Package 'PopED'

Title: Population (and Individual) Optimal Experimental Design
Description: Optimal experimental designs for both population and individual studies based on nonlinear mixed-effect models. Often this is based on a computation of the Fisher Information Matrix. This package was developed for pharmacometric problems, and examples and predefined models are available for these types of systems. The methods are described in Nyberg et al. (2012) <doi:10.1016/j.cmpb.2012.05.005>, and Foracchia et al. (2004) <doi:10.1016/S0169-2607(03)00073-7>.
Authors: Andrew C. Hooker [aut, cre, trl, cph] , Marco Foracchia [aut] (O-Matrix version), Eric Stroemberg [ctb] (MATLAB version), Martin Fink [ctb] (Streamlining code, added functionality, vignettes), Giulia Lestini [ctb] (Streamlining code, added functionality, vignettes), Sebastian Ueckert [aut] (MATLAB version, <https://orcid.org/0000-0002-3712-0255>), Joakim Nyberg [aut] (MATLAB version)
Maintainer: Andrew C. Hooker <[email protected]>
License: LGPL (>= 3)
Version: 0.7.0
Built: 2024-12-07 06:32:39 UTC
Source: CRAN

Help Index

Optimize using line search

Description

The function performs a grid search sequentially along design variables. The grid is defined by ls_step_size.

Usage

a_line_search(
  poped.db,
  out_file = "",
  bED = FALSE,
  diff = 0,
  fmf_initial = 0,
  dmf_initial = 0,
  opt_xt = poped.db$settings$optsw[2],
  opt_a = poped.db$settings$optsw[4],
  opt_x = poped.db$settings$optsw[3],
  opt_samps = poped.db$settings$optsw[1],
  opt_inds = poped.db$settings$optsw[5],
  ls_step_size = poped.db$settings$ls_step_size
)

Arguments

poped.db

A PopED database.
out_file

The output file to write to.
bED

If the algorithm should use E-family methods. Logical.
diff

The OFV difference that is deemed significant for changing a design. If, by changing a design variable the difference between the new and old OFV is less than diff the change is not made.
fmf_initial

The initial value of the FIM. If 0 then the FIM is calculated from poped.db.
dmf_initial

The initial value of the objective function value (OFV). If 0 then the OFV is calculated from poped.db.
opt_xt

Should the sample times be optimized?
opt_a

Should the continuous design variables be optimized?
opt_x

Should the discrete design variables be optimized?
opt_samps

Are the number of sample times per group being optimized?
opt_inds

Are the number of individuals per group being optimized?
ls_step_size

Number of grid points in the line search.

Value

A list containing:

fmf

The FIM.
dmf

The final value of the objective function value.
best_changed

If the algorithm has found a better design than the starting design.
xt

A matrix of sample times. Each row is a vector of sample times for a group.
x

A matrix for the discrete design variables. Each row is a group.
a

A matrix of covariates. Each row is a group.
poped.db

A PopED database.

See Also

Other Optimize: Doptim(), LEDoptim(), RS_opt(), bfgsb_min(), calc_autofocus(), calc_ofv_and_grad(), mfea(), optim_ARS(), optim_LS(), poped_optim(), poped_optim_1(), poped_optim_2(), poped_optim_3(), poped_optimize()

Examples

library(PopED)

############# START #################
## Create PopED database
## (warfarin model for optimization)
#####################################

## Warfarin example from software comparison in:
## Nyberg et al., "Methods and software tools for design evaluation 
##   for population pharmacokinetics-pharmacodynamics studies", 
##   Br. J. Clin. Pharm., 2014. 

## Optimization using an additive + proportional reidual error  
## to avoid sample times at very low concentrations (time 0 or very late samples).

## find the parameters that are needed to define from the structural model
ff.PK.1.comp.oral.sd.CL

## -- parameter definition function 
## -- names match parameters in function ff
sfg <- function(x,a,bpop,b,bocc){
  parameters=c(CL=bpop[1]*exp(b[1]),
               V=bpop[2]*exp(b[2]),
               KA=bpop[3]*exp(b[3]),
               Favail=bpop[4],
               DOSE=a[1])
  return(parameters) 
}

## -- Define initial design  and design space
poped.db <- create.poped.database(ff_fun=ff.PK.1.comp.oral.sd.CL,
                                  fg_fun=sfg,
                                  fError_fun=feps.add.prop,
                                  bpop=c(CL=0.15, V=8, KA=1.0, Favail=1), 
                                  notfixed_bpop=c(1,1,1,0),
                                  d=c(CL=0.07, V=0.02, KA=0.6), 
                                  sigma=c(prop=0.01,add=0.25),
                                  groupsize=32,
                                  xt=c( 0.5,1,2,6,24,36,72,120),
                                  minxt=0.01,
                                  maxxt=120,
                                  a=c(DOSE=70),
                                  mina=c(DOSE=0.01),
                                  maxa=c(DOSE=100))

############# END ###################
## Create PopED database
## (warfarin model for optimization)
#####################################


# very sparse grid to evaluate (4 points for each design valiable)
output <- a_line_search(poped.db, opt_xt=TRUE, opt_a=TRUE, ls_step_size=4)

## Not run:   
  
  # longer run time
  output <- a_line_search(poped.db,opt_xt=TRUE)
  
  # output to a text file
  output <- a_line_search(poped.db,opt_xt=TRUE,out_file="tmp.txt")
  

## End(Not run)

Build PopED parameter function from a model function

Description

Build PopED parameter function from a model function

Usage

build_sfg(
  model = "ff.PK.1.comp.oral.sd.CL",
  covariates = c("dose", "tau"),
  par_names = NULL,
  etas = "exp",
  no_etas = c("F", "Favail"),
  env = parent.frame()
)

Arguments

model

A string of text describing the model function name
covariates

A list of covariate names to be filtered out of the model
par_names

A list of parameter names in the model file. If not supplied then all undefined variables in the model file are extracted and the covariate names are filtered out of that list.
etas

Can be "exp", "prop", "add" or "none". Either one value for all parameters or a list defining the model per parameter.
no_etas

Parameters that should not have etas associated with them.
env

The environment to create the function in.

Value

A parameter model function to be used as input to PopED calculations.

Examples

build_sfg(model="ff.PK.1.comp.oral.md.CL")

etas <- c(Favail="exp",KA="exp",V="add",CL="exp")
build_sfg(model="ff.PK.1.comp.oral.md.CL",etas = etas)

Calculate the Fisher Information Matrix (FIM) and the OFV(FIM) for either point values or parameters or distributions.

Description

This function computes the expectation of the FIM and OFV(FIM) for either point values of parameter estimates or parameter distributions given the model, parameters, distributions of parameter uncertainty, design and methods defined in the PopED database.

Usage

calc_ofv_and_fim(
  poped.db,
  ofv = 0,
  fim = 0,
  d_switch = poped.db$settings$d_switch,
  bpopdescr = poped.db$parameters$bpop,
  ddescr = poped.db$parameters$d,
  bpop = bpopdescr[, 2, drop = F],
  d = getfulld(ddescr[, 2, drop = F], poped.db$parameters$covd),
  docc_full = getfulld(poped.db$parameters$docc[, 2, drop = F],
    poped.db$parameters$covdocc),
  model_switch = poped.db$design$model_switch,
  ni = poped.db$design$ni,
  xt = poped.db$design$xt,
  x = poped.db$design$x,
  a = poped.db$design$a,
  fim.calc.type = poped.db$settings$iFIMCalculationType,
  use_laplace = poped.db$settings$iEDCalculationType,
  laplace.fim = FALSE,
  ofv_fun = poped.db$settings$ofv_fun,
  evaluate_fim = TRUE,
  ...
)

Arguments

poped.db

A PopED database.
ofv

The current ofv. If other than zero then this value is simply returned unchanged.
fim

The current FIM. If other than zero then this value is simply returned unchanged.
d_switch

  • ******START OF CRITERION SPECIFICATION OPTIONS**********

D-family design (1) or ED-family design (0) (with or without parameter uncertainty)
bpopdescr

Matrix defining the fixed effects, per row (row number = parameter_number) we should have:

  • column 1 the type of the distribution for E-family designs (0 = Fixed, 1 = Normal, 2 = Uniform, 3 = User Defined Distribution, 4 = lognormal and 5 = truncated normal)

  • column 2 defines the mean.

  • column 3 defines the variance of the distribution (or length of uniform distribution).

ddescr

Matrix defining the diagonals of the IIV (same logic as for the bpopdescr).
bpop

Matrix defining the fixed effects, per row (row number = parameter_number) we should have:

  • column 1 the type of the distribution for E-family designs (0 = Fixed, 1 = Normal, 2 = Uniform, 3 = User Defined Distribution, 4 = lognormal and 5 = truncated normal)

  • column 2 defines the mean.

  • column 3 defines the variance of the distribution (or length of uniform distribution).

Can also just supply the parameter values as a vector c() if no uncertainty around the parameter value is to be used. The parameter order of 'bpop' is defined in the 'fg_fun' or 'fg_file'. If you use named arguments in 'bpop' then the order of this vector can be rearranged to match the 'fg_fun' or 'fg_file'. See 'reorder_parameter_vectors'.
d

Matrix defining the diagonals of the IIV (same logic as for the fixed effects matrix bpop to define uncertainty). One can also just supply the parameter values as a c(). The parameter order of 'd' is defined in the 'fg_fun' or 'fg_file'. If you use named arguments in 'd' then the order of this vector can be rearranged to match the 'fg_fun' or 'fg_file'. See 'reorder_parameter_vectors'.
docc_full

A between occasion variability matrix.
model_switch

A matrix that is the same size as xt, specifying which model each sample belongs to.
ni

A vector of the number of samples in each group.
xt

A matrix of sample times. Each row is a vector of sample times for a group.
x

A matrix for the discrete design variables. Each row is a group.
a

A matrix of covariates. Each row is a group.
fim.calc.type

The method used for calculating the FIM. Potential values:

  • 0 = Full FIM. No assumption that fixed and random effects are uncorrelated.

  • 1 = Reduced FIM. Assume that there is no correlation in the FIM between the fixed and random effects, and set these elements in the FIM to zero.

  • 2 = weighted models (placeholder).

  • 3 = Not currently used.

  • 4 = Reduced FIM and computing all derivatives with respect to the standard deviation of the residual unexplained variation (sqrt(SIGMA) in NONMEM). This matches what is done in PFIM, and assumes that the standard deviation of the residual unexplained variation is the estimated parameter (NOTE: NONMEM estimates the variance of the residual unexplained variation by default).

  • 5 = Full FIM parameterized with A,B,C matrices & derivative of variance.

  • 6 = Calculate one model switch at a time, good for large matrices.

  • 7 = Reduced FIM parameterized with A,B,C matrices & derivative of variance.

use_laplace

Should the Laplace method be used in calculating the expectation of the OFV?
laplace.fim

Should an E(FIM) be calculated when computing the Laplace approximated E(OFV). Typically the FIM does not need to be computed and, if desired, this calculation is done using the standard MC integration technique, so can be slow.
ofv_fun

User defined function used to compute the objective function. The function must have a poped database object as its first argument and have "..." in its argument list. Can be referenced as a function or as a file name where the function defined in the file has the same name as the file. e.g. "cost.txt" has a function named "cost" in it.
evaluate_fim

Should the FIM be calculated?
...

Other arguments passed to the function.

Value

A list containing the FIM and OFV(FIM) or the E(FIM) and E(OFV(FIM)) according to the function arguments.

See Also

Other FIM: LinMatrixH(), LinMatrixLH(), LinMatrixL_occ(), ed_laplace_ofv(), ed_mftot(), efficiency(), evaluate.e.ofv.fim(), evaluate.fim(), gradf_eps(), mf3(), mf7(), mftot(), ofv_criterion(), ofv_fim()

Other E-family: ed_laplace_ofv(), ed_mftot(), evaluate.e.ofv.fim()

Other evaluate_FIM: evaluate.e.ofv.fim(), evaluate.fim(), ofv_fim()

Examples

library(PopED)

############# START #################
## Create PopED database
## (warfarin model for optimization
##  with parameter uncertainty)
#####################################

## Warfarin example from software comparison in:
## Nyberg et al., "Methods and software tools for design evaluation 
##   for population pharmacokinetics-pharmacodynamics studies", 
##   Br. J. Clin. Pharm., 2014. 

## Optimization using an additive + proportional reidual error
## to avoid sample times at very low concentrations (time 0 or very late samoples).

## find the parameters that are needed to define from the structural model
ff.PK.1.comp.oral.sd.CL

## -- parameter definition function 
## -- names match parameters in function ff
sfg <- function(x,a,bpop,b,bocc){
  parameters=c(CL=bpop[1]*exp(b[1]),
               V=bpop[2]*exp(b[2]),
               KA=bpop[3]*exp(b[3]),
               Favail=bpop[4],
               DOSE=a[1])
  return(parameters) 
}

# Adding 10% log-normal Uncertainty to fixed effects (not Favail)
bpop_vals <- c(CL=0.15, V=8, KA=1.0, Favail=1)
bpop_vals_ed_ln <- cbind(ones(length(bpop_vals),1)*4, # log-normal distribution
                         bpop_vals,
                         ones(length(bpop_vals),1)*(bpop_vals*0.1)^2) # 10% of bpop value
bpop_vals_ed_ln["Favail",]  <- c(0,1,0)
bpop_vals_ed_ln

## -- Define initial design  and design space
poped.db <- create.poped.database(ff_fun=ff.PK.1.comp.oral.sd.CL,
                                  fg_fun=sfg,
                                  fError_fun=feps.add.prop,
                                  bpop=bpop_vals_ed_ln, 
                                  notfixed_bpop=c(1,1,1,0),
                                  d=c(CL=0.07, V=0.02, KA=0.6), 
                                  sigma=c(0.01,0.25),
                                  groupsize=32,
                                  xt=c( 0.5,1,2,6,24,36,72,120),
                                  minxt=0,
                                  maxxt=120,
                                  a=70,
                                  mina=0,
                                  maxa=100)

############# END ###################
## Create PopED database
## (warfarin model for optimization
##  with parameter uncertainty)
#####################################


calc_ofv_and_fim(poped.db)

## Not run: 
  
  calc_ofv_and_fim(poped.db,d_switch=0)
  calc_ofv_and_fim(poped.db,d_switch=0,use_laplace=TRUE)
  calc_ofv_and_fim(poped.db,d_switch=0,use_laplace=TRUE,laplace.fim=TRUE)


## End(Not run)

Create a cell array (a matrix of lists)

Description

Create a cell array as in MATLAB.

Usage

cell(...)

Arguments

...

Dimensions for the cell array.

Value

A list of empty lists.

Note

This is a modified version of the same function in the matlab R-package.

See Also

Other MATLAB: diag_matlab(), feval(), fileparts(), isempty(), ones(), rand(), randn(), size(), tic(), toc(), zeros()

Examples

cell(3)
cell(2,3)

## define possible values of 2 categorical design variable
x.space <- cell(1,2)
x.space[1,1] <- list(seq(10,100,10))
x.space[1,2] <- list(seq(10,300,10))
x.space
x.space[1,1]
x.space[1,2]

Create design variables for a full description of a design.

Description

Create design variables to fully describe a design. If variables are supplied then these variables are checked for consistency and, if possible, changed to sizes that make sense if there are inconsistencies. Returns a list of matricies compatible with PopED.

Usage

create_design(
  xt,
  groupsize,
  m = NULL,
  x = NULL,
  a = NULL,
  ni = NULL,
  model_switch = NULL
)

Arguments

xt

Matrix defining the sampling schedule. Each row is a group.
groupsize

Vector defining the size of the different groups (number of individuals in each group).
m

A number defining the number of groups. Computed from xt if not defined.
x

A matrix defining the discrete design variables for the model Each row is a group.
a

Matrix defining the continuous design variables. Each row is a group.
ni

Vector defining the number of samples for each group, computed as all elements of xt for each group by default.
model_switch

Matrix defining which response a certain sampling time belongs to. Defaults to one for all elements of xt.

Details

If a value (or a vector/list of values) is supplied that corresponds to only one group and the design has multiple groups then all groups will have the same value(s). If a matrix is expected then a list of lists can be supplied instead, each list corresponding to a group.

See Also

Other poped_input: convert_variables(), create.poped.database(), create_design_space(), downsizing_general_design(), poped.choose()

Examples

library(PopED)

xt1 <- list(c(1,2,3),c(1,2,3,4))
xt4 <- list(c(1,2,3,4,5),c(1,2,3,4))
xt2 <- rbind(c(1,2,3,4),c(1,2,3,4))
xt3 <- c(1,2,3,4)

design_1 <- create_design(xt=xt1,groupsize=20)
design_2 <- create_design(xt=xt4,groupsize=20)
design_3 <- create_design(xt=xt2,groupsize=20)
design_4 <- create_design(xt=xt3,groupsize=20)

design_5 <- create_design(xt=xt3,groupsize=20,m=3)

design_6 <- create_design(xt=xt1,groupsize=20,model_switch=ones(2,4))

design_7 <-create_design(xt=xt1,groupsize=20,a=c(2,3,4))
design_8 <-create_design(xt=xt1,groupsize=20,a=rbind(c(2,3,4),c(4,5,6)))
design_9 <-create_design(xt=xt1,groupsize=20,a=list(c(2,3,4,6),c(4,5,6)))
design_10 <-create_design(xt=xt1,groupsize=20,a=list(c(2,3,4),c(4,5,6)))

design_11 <-create_design(xt=c(0,1,2,4,6,8,24),
                         groupsize=50,
                         a=c(WT=70,DOSE=1000))

design_12 <-create_design(xt=c(0,1,2,4,6,8,24),
                         groupsize=50,
                         a=c(WT=70,DOSE=1000),m=2)

design_13 <-create_design(xt=c(0,1,2,4,6,8,24),
                         groupsize=50,
                         a=list(c(WT=70,DOSE=1000),c(DOSE=90,WT=200,AGE=45)),m=2)

design_14 <-create_design(xt=c(0,1,2,4,6,8,24),
                         groupsize=50,
                         a=list(list(WT=70,DOSE=1000),list(DOSE=90,WT=200,AGE=45)),m=2)

design_15 <-create_design(xt=xt4,
                          groupsize=c(50,20),
                          a=rbind(c("DOSE"=2,"WT"=3,"AGE"=4),
                                  c(4,5,6)))

Create design variables and a design space for a full description of an optimization problem.

Description

create_design_space takes an initial design and arguments for a design space and creates a design and design space for design optimization. Checks the sizes of supplied design space variables and changes them to sizes that make sense if there are inconsistencies. Function arguments can use shorthand notation (single values, vectors, lists of vectors and list of list) or matricies. Returns a list of matricies compatible with PopED.

Usage

create_design_space(
  design,
  maxni = NULL,
  minni = NULL,
  maxtotni = NULL,
  mintotni = NULL,
  maxgroupsize = NULL,
  mingroupsize = NULL,
  maxtotgroupsize = NULL,
  mintotgroupsize = NULL,
  maxxt = NULL,
  minxt = NULL,
  xt_space = NULL,
  maxa = NULL,
  mina = NULL,
  a_space = NULL,
  x_space = NULL,
  use_grouped_xt = FALSE,
  grouped_xt = NULL,
  use_grouped_a = FALSE,
  grouped_a = NULL,
  use_grouped_x = FALSE,
  grouped_x = NULL,
  our_zero = NULL
)

Arguments

design

The output from a call to create_design.
maxni

Vector defining the maximum number of samples per group.
minni

Vector defining the minimum number of samples per group.
maxtotni

Number defining the maximum number of samples allowed in the experiment.
mintotni

Number defining the minimum number of samples allowed in the experiment.
maxgroupsize

Vector defining the maximum size of the different groups (maximum number of individuals in each group)
mingroupsize

Vector defining the minimum size of the different groups (minimum num individuals in each group)
maxtotgroupsize

The total maximal groupsize over all groups
mintotgroupsize

The total minimal groupsize over all groups
maxxt

Matrix or single value defining the maximum value for each xt sample. If a single value is supplied then all xt values are given the same maximum value.
minxt

Matrix or single value defining the minimum value for each xt sample. If a single value is supplied then all xt values are given the same minimum value
xt_space

Cell array cell defining the discrete variables allowed for each xt value. Can also be a vector of values c(1:10) (same values allowed for all xt), or a list of lists list(1:10, 2:23, 4:6) (one for each value in xt in row major order or just for one row in xt, and all other rows will be duplicated).
maxa

Vector defining the maximum value for each covariate. IF a single value is supplied then all a values are given the same maximum value
mina

Vector defining the minimum value for each covariate. IF a single value is supplied then all a values are given the same minimum value
a_space

Cell array cell defining the discrete variables allowed for each a value. Can also be a list of values list(1:10) (same values allowed for all a), or a list of lists list(1:10, 2:23, 4:6) (one for each value in a).
x_space

Cell array cell defining the discrete variables for each x value.
use_grouped_xt

Group sampling times between groups so that each group has the same values (TRUE or FALSE).
grouped_xt

Matrix defining the grouping of sample points. Matching integers mean that the points are matched. Allows for finer control than use_grouped_xt
use_grouped_a

Group continuous design variables between groups so that each group has the same values (TRUE or FALSE).
grouped_a

Matrix defining the grouping of continuous design variables. Matching integers mean that the values are matched. Allows for finer control than use_grouped_a.
use_grouped_x

Group discrete design variables between groups so that each group has the same values (TRUE or FALSE).
grouped_x

Matrix defining the grouping of discrete design variables. Matching integers mean that the values are matched. Allows for finer control than use_grouped_x.
our_zero

Value to interpret as zero in design.

Details

If a value (or a vector or a list of values) is supplied that corresponds to only one group and the design has multiple groups then all groups will have the same value(s). If a matrix is expected then a list of lists can be supplied instead, each list corresponding to a group.

See Also

Other poped_input: convert_variables(), create.poped.database(), create_design(), downsizing_general_design(), poped.choose()

Examples

library(PopED)

design_1 <- create_design(xt=list(c(1,2,3,4,5),
                                  c(1,2,3,4)),
                          groupsize=c(50,20),
                          a=list(c(WT=70,DOSE=1000),
                                 c(DOSE=1000,WT=35)))

ds_1 <- create_design_space(design_1)

ds_1_a <- create_design_space(design_1,our_zero = 1e-5)

ds_2 <- create_design_space(design_1,maxni=10,maxxt=10,minxt=0)

ds_3 <- create_design_space(design_1,maxni=10,mingroupsize=20,maxxt=10,minxt=0)

ds_4 <- create_design_space(design_1,maxa=c(100,2000))

ds_5 <- create_design_space(design_1,mina=c(10,20))

design_2 <- create_design(xt=list(c(1,2,3,4,5),
                                  c(1,2,3,4)),
                          groupsize=c(50,20),
                          a=list(c(WT=70,DOSE=1000),
                                 c(WT=35,DOSE=1000)),
                          x=list(c(SEX=1,DOSE_discrete=100),
                                 c(SEX=2,DOSE_discrete=200)))

ds_6 <- create_design_space(design_2) 

ds_7 <- create_design_space(design_2,
                            x_space=list(SEX=c(1,2),
                                         DOSE_discrete=seq(100,400,by=20)))

ds_8 <- create_design_space(design_2,
                            x_space=list(SEX=c(1,2),
                                         DOSE_discrete=seq(100,400,by=20)),
                            grouped_xt=c(1,2,3,4,5))

ds_9 <- create_design_space(design_2,
                            x_space=list(SEX=c(1,2),
                                         DOSE_discrete=seq(100,400,by=20)),
                            use_grouped_xt=TRUE)

design_3 <- create_design(xt=list(c(1,2,3,4,5),
                                  c(1,2,3,4)),
                          groupsize=c(50,20),
                          a=list(c(WT=35,DOSE=1000)),
                          x=list(c(SEX=1,DOSE_discrete=100)))

ds_10 <- create_design_space(design_3,
                             x_space=list(SEX=c(1,2),DOSE_discrete=seq(100,400,by=20)),
                             use_grouped_a=TRUE)

ds_11 <- create_design_space(design_2,
                             x_space=list(SEX=c(1,2),DOSE_discrete=seq(100,400,by=20)),
                             grouped_a=list(c(1,2),c(3,2)))

ds_12 <- create_design_space(design_3,
                             x_space=list(SEX=c(1,2),DOSE_discrete=seq(100,400,by=20)),
                             use_grouped_x=TRUE)

ds_13 <- create_design_space(design_3,
                             x_space=list(SEX=c(1,2),DOSE_discrete=seq(100,400,by=20)),
                             grouped_x=list(c(1,2),c(3,2)))

seq_1 <- 1:10
ds_14 <- create_design_space(design_1,maxxt=10,minxt=0,
                             xt_space = list(seq_1,seq_1,seq_1,seq_1,seq_1))
ds_15 <- create_design_space(design_1,maxxt=10,minxt=0,xt_space = list(seq_1))

possible_values <- as.matrix(cbind(list(0:10),list(0:10),list(0:10),list(0:20),list(0:20)))
xt_space <- as.matrix(rbind(possible_values,possible_values))

ds_16 <- create_design_space(design_1,maxxt=10,minxt=0,xt_space = xt_space)

ds_17 <- create_design_space(design_1,a_space = list(1:100,seq(1000,100000,by=1000)))

Create a PopED database

Description

This function takes the input file (a previously created poped database) supplied by the user, or function arguments, and creates a database that can then be used to run all other PopED functions. The function supplies default values to elements of the database that are not specified in the input file or as function arguments. Default arguments are supplied in the Usage section (easiest to use a text search to find values you are interested in).

Usage

create.poped.database(
  popedInput = list(),
  ff_file = NULL,
  ff_fun = poped.choose(popedInput$model$ff_pointer, NULL),
  fg_file = NULL,
  fg_fun = poped.choose(popedInput$model$fg_pointer, NULL),
  fError_file = NULL,
  fError_fun = poped.choose(popedInput$model$ferror_pointer, NULL),
  optsw = poped.choose(popedInput$settings$optsw, cbind(0, 0, 0, 0, 0)),
  xt = poped.choose(popedInput$design[["xt"]], stop("'xt' needs to be defined")),
  m = poped.choose(popedInput$design[["m"]], NULL),
  x = poped.choose(popedInput$design[["x"]], NULL),
  nx = poped.choose(popedInput$design$nx, NULL),
  a = poped.choose(popedInput$design[["a"]], NULL),
  groupsize = poped.choose(popedInput$design$groupsize,
    stop("'groupsize' needs to be defined")),
  ni = poped.choose(popedInput$design$ni, NULL),
  model_switch = poped.choose(popedInput$design$model_switch, NULL),
  maxni = poped.choose(popedInput$design_space$maxni, NULL),
  minni = poped.choose(popedInput$design_space$minni, NULL),
  maxtotni = poped.choose(popedInput$design_space$maxtotni, NULL),
  mintotni = poped.choose(popedInput$design_space$mintotni, NULL),
  maxgroupsize = poped.choose(popedInput$design_space$maxgroupsize, NULL),
  mingroupsize = poped.choose(popedInput$design_space$mingroupsize, NULL),
  maxtotgroupsize = poped.choose(popedInput$design_space$maxtotgroupsize, NULL),
  mintotgroupsize = poped.choose(popedInput$design_space$mintotgroupsize, NULL),
  maxxt = poped.choose(popedInput$design_space$maxxt, NULL),
  minxt = poped.choose(popedInput$design_space$minxt, NULL),
  discrete_xt = poped.choose(popedInput$design_space$xt_space, NULL),
  discrete_x = poped.choose(popedInput$design_space$discrete_x, NULL),
  maxa = poped.choose(popedInput$design_space$maxa, NULL),
  mina = poped.choose(popedInput$design_space$mina, NULL),
  discrete_a = poped.choose(popedInput$design_space$a_space, NULL),
  bUseGrouped_xt = poped.choose(popedInput$design_space$bUseGrouped_xt, FALSE),
  G_xt = poped.choose(popedInput$design_space$G_xt, NULL),
  bUseGrouped_a = poped.choose(popedInput$design_space$bUseGrouped_a, FALSE),
  G_a = poped.choose(popedInput$design_space$G_a, NULL),
  bUseGrouped_x = poped.choose(popedInput$design_space$bUseGrouped_x, FALSE),
  G_x = poped.choose(popedInput$design_space[["G_x"]], NULL),
  iFIMCalculationType = poped.choose(popedInput$settings$iFIMCalculationType, 1),
  iApproximationMethod = poped.choose(popedInput$settings$iApproximationMethod, 0),
  iFOCENumInd = poped.choose(popedInput$settings$iFOCENumInd, 1000),
  prior_fim = poped.choose(popedInput$settings$prior_fim, matrix(0, 0, 1)),
  strAutoCorrelationFile = poped.choose(popedInput$model$auto_pointer, ""),
  d_switch = poped.choose(popedInput$settings$d_switch, 1),
  ofv_calc_type = poped.choose(popedInput$settings$ofv_calc_type, 4),
  ds_index = popedInput$parameters$ds_index,
  strEDPenaltyFile = poped.choose(popedInput$settings$strEDPenaltyFile, ""),
  ofv_fun = poped.choose(popedInput$settings$ofv_fun, NULL),
  iEDCalculationType = poped.choose(popedInput$settings$iEDCalculationType, 0),
  ED_samp_size = poped.choose(popedInput$settings$ED_samp_size, 45),
  bLHS = poped.choose(popedInput$settings$bLHS, 1),
  strUserDistributionFile = poped.choose(popedInput$model$user_distribution_pointer, ""),
  nbpop = popedInput$parameters$nbpop,
  NumRanEff = popedInput$parameters$NumRanEff,
  NumDocc = popedInput$parameters$NumDocc,
  NumOcc = popedInput$parameters$NumOcc,
  bpop = poped.choose(popedInput$parameters$bpop, stop("bpop must be defined")),
  d = poped.choose(popedInput$parameters$d, NULL),
  covd = popedInput$parameters$covd,
  sigma = popedInput$parameters$sigma,
  docc = poped.choose(popedInput$parameters$docc, matrix(0, 0, 3)),
  covdocc = poped.choose(popedInput$parameters$covdocc, zeros(1, length(docc[, 2, drop =
    F]) * (length(docc[, 2, drop = F]) - 1)/2)),
  notfixed_bpop = popedInput$parameters$notfixed_bpop,
  notfixed_d = popedInput$parameters$notfixed_d,
  notfixed_covd = popedInput$parameters$notfixed_covd,
  notfixed_docc = popedInput$parameters$notfixed_docc,
  notfixed_covdocc = poped.choose(popedInput$parameters$notfixed_covdocc, zeros(1,
    length(covdocc))),
  notfixed_sigma = poped.choose(popedInput$parameters$notfixed_sigma, t(rep(1,
    size(sigma, 2)))),
  notfixed_covsigma = poped.choose(popedInput$parameters$notfixed_covsigma, zeros(1,
    length(notfixed_sigma) * (length(notfixed_sigma) - 1)/2)),
  reorder_parameter_vectors = FALSE,
  bUseRandomSearch = poped.choose(popedInput$settings$bUseRandomSearch, TRUE),
  bUseStochasticGradient = poped.choose(popedInput$settings$bUseStochasticGradient, TRUE),
  bUseLineSearch = poped.choose(popedInput$settings$bUseLineSearch, TRUE),
  bUseExchangeAlgorithm = poped.choose(popedInput$settings$bUseExchangeAlgorithm, FALSE),
  bUseBFGSMinimizer = poped.choose(popedInput$settings$bUseBFGSMinimizer, FALSE),
  EACriteria = poped.choose(popedInput$settings$EACriteria, 1),
  strRunFile = poped.choose(popedInput$settings$run_file_pointer, ""),
  poped_version = poped.choose(popedInput$settings$poped_version,
    packageVersion("PopED")),
  modtit = poped.choose(popedInput$settings$modtit, "PopED model"),
  output_file = poped.choose(popedInput$settings$output_file, paste("PopED_output",
    "_summary", sep = "")),
  output_function_file = poped.choose(popedInput$settings$output_function_file,
    paste("PopED", "_output_", sep = "")),
  strIterationFileName = poped.choose(popedInput$settings$strIterationFileName,
    paste("PopED", "_current.R", sep = "")),
  user_data = poped.choose(popedInput$settings$user_data, cell(0, 0)),
  ourzero = poped.choose(popedInput$settings$ourzero, 1e-05),
  dSeed = poped.choose(popedInput$settings$dSeed, NULL),
  line_opta = poped.choose(popedInput$settings$line_opta, NULL),
  line_optx = poped.choose(popedInput$settings$line_optx, NULL),
  bShowGraphs = poped.choose(popedInput$settings$bShowGraphs, FALSE),
  use_logfile = poped.choose(popedInput$settings$use_logfile, FALSE),
  m1_switch = poped.choose(popedInput$settings$m1_switch, 1),
  m2_switch = poped.choose(popedInput$settings$m2_switch, 1),
  hle_switch = poped.choose(popedInput$settings$hle_switch, 1),
  gradff_switch = poped.choose(popedInput$settings$gradff_switch, 1),
  gradfg_switch = poped.choose(popedInput$settings$gradfg_switch, 1),
  grad_all_switch = poped.choose(popedInput$settings$grad_all_switch, 1),
  rsit_output = poped.choose(popedInput$settings$rsit_output, 5),
  sgit_output = poped.choose(popedInput$settings$sgit_output, 1),
  hm1 = poped.choose(popedInput$settings[["hm1"]], 1e-05),
  hlf = poped.choose(popedInput$settings[["hlf"]], 1e-05),
  hlg = poped.choose(popedInput$settings[["hlg"]], 1e-05),
  hm2 = poped.choose(popedInput$settings[["hm2"]], 1e-05),
  hgd = poped.choose(popedInput$settings[["hgd"]], 1e-05),
  hle = poped.choose(popedInput$settings[["hle"]], 1e-05),
  AbsTol = poped.choose(popedInput$settings$AbsTol, 1e-06),
  RelTol = poped.choose(popedInput$settings$RelTol, 1e-06),
  iDiffSolverMethod = poped.choose(popedInput$settings$iDiffSolverMethod, NULL),
  bUseMemorySolver = poped.choose(popedInput$settings$bUseMemorySolver, FALSE),
  rsit = poped.choose(popedInput$settings[["rsit"]], 300),
  sgit = poped.choose(popedInput$settings[["sgit"]], 150),
  intrsit = poped.choose(popedInput$settings$intrsit, 250),
  intsgit = poped.choose(popedInput$settings$intsgit, 50),
  maxrsnullit = poped.choose(popedInput$settings$maxrsnullit, 50),
  convergence_eps = poped.choose(popedInput$settings$convergence_eps, 1e-08),
  rslxt = poped.choose(popedInput$settings$rslxt, 10),
  rsla = poped.choose(popedInput$settings$rsla, 10),
  cfaxt = poped.choose(popedInput$settings$cfaxt, 0.001),
  cfaa = poped.choose(popedInput$settings$cfaa, 0.001),
  bGreedyGroupOpt = poped.choose(popedInput$settings$bGreedyGroupOpt, FALSE),
  EAStepSize = poped.choose(popedInput$settings$EAStepSize, 0.01),
  EANumPoints = poped.choose(popedInput$settings$EANumPoints, FALSE),
  EAConvergenceCriteria = poped.choose(popedInput$settings$EAConvergenceCriteria, 1e-20),
  bEANoReplicates = poped.choose(popedInput$settings$bEANoReplicates, FALSE),
  BFGSConvergenceCriteriaMinStep = NULL,
  BFGSProjectedGradientTol = poped.choose(popedInput$settings$BFGSProjectedGradientTol,
    1e-04),
  BFGSTolerancef = poped.choose(popedInput$settings$BFGSTolerancef, 0.001),
  BFGSToleranceg = poped.choose(popedInput$settings$BFGSToleranceg, 0.9),
  BFGSTolerancex = poped.choose(popedInput$settings$BFGSTolerancex, 0.1),
  ED_diff_it = poped.choose(popedInput$settings$ED_diff_it, 30),
  ED_diff_percent = poped.choose(popedInput$settings$ED_diff_percent, 10),
  line_search_it = poped.choose(popedInput$settings$ls_step_size, 50),
  Doptim_iter = poped.choose(popedInput$settings$iNumSearchIterationsIfNotLineSearch, 1),
  iCompileOption = poped.choose(popedInput$settings$parallel$iCompileOption, -1),
  iUseParallelMethod = poped.choose(popedInput$settings$parallel$iUseParallelMethod, 1),
  MCC_Dep = NULL,
  strExecuteName = poped.choose(popedInput$settings$parallel$strExecuteName,
    "calc_fim.exe"),
  iNumProcesses = poped.choose(popedInput$settings$parallel$iNumProcesses, 2),
  iNumChunkDesignEvals = poped.choose(popedInput$settings$parallel$iNumChunkDesignEvals,
    -2),
  Mat_Out_Pre = poped.choose(popedInput$settings$parallel$strMatFileOutputPrefix,
    "parallel_output"),
  strExtraRunOptions = poped.choose(popedInput$settings$parallel$strExtraRunOptions, ""),
  dPollResultTime = poped.choose(popedInput$settings$parallel$dPollResultTime, 0.1),
  strFunctionInputName = poped.choose(popedInput$settings$parallel$strFunctionInputName,
    "function_input"),
  bParallelRS = poped.choose(popedInput$settings$parallel$bParallelRS, FALSE),
  bParallelSG = poped.choose(popedInput$settings$parallel$bParallelSG, FALSE),
  bParallelMFEA = poped.choose(popedInput$settings$parallel$bParallelMFEA, FALSE),
  bParallelLS = poped.choose(popedInput$settings$parallel$bParallelLS, FALSE)
)

Arguments

popedInput

A PopED database file or an empty list list(). List elements should match the values seen in the Usage section (the defaults to function arguments).
ff_file

  • ******START OF MODEL DEFINITION OPTIONS**********

A string giving the function name or filename and path of the structural model. The filename and the function name must be the same if giving a filename. e.g. "ff.PK.1.comp.oral.md.KE"
ff_fun

Function describing the structural model. e.g. ff.PK.1.comp.oral.md.KE.
fg_file

A string giving the function name or filename and path of the parameter model. The filename and the function name must be the same if giving a filename. e.g. "parameter.model"
fg_fun

Function describing the parameter model. e.g. parameter.model.
fError_file

A string giving the function name or filename and path of the residual error model. The filename and the function name must be the same if giving a filename. e.g. "feps.prop".
fError_fun

Function describing the residual error model. e.g. feps.prop.
optsw

  • ******WHAT TO OPTIMIZE**********

Row vector of optimization tasks (1=TRUE,0=FALSE) in the following order: (Samples per subject, Sampling schedule, Discrete design variable, Continuous design variable, Number of id per group). All elements set to zero => only calculate the FIM with current design
xt

  • ******START OF INITIAL DESIGN OPTIONS**********

Matrix defining the initial sampling schedule. Each row is a group/individual. If only one vector is supplied, e.g. c(1,2,3,4), then all groups will have the same initial design.
m

Number of groups in the study. Each individual in a group will have the same design.
x

A matrix defining the initial discrete values for the model Each row is a group/individual.
nx

Number of discrete design variables.
a

Matrix defining the initial continuous covariate values. n_rows=number of groups, n_cols=number of covariates. If the number of rows is one and the number of groups > 1 then all groups are assigned the same values.
groupsize

Vector defining the size of the different groups (num individuals in each group). If only one number then the number will be the same in every group.
ni

Vector defining the number of samples for each group.
model_switch

Matrix defining which response a certain sampling time belongs to.
maxni

  • ******START OF DESIGN SPACE OPTIONS**********

Max number of samples per group/individual
minni

Min number of samples per group/individual
maxtotni

Number defining the maximum number of samples allowed in the experiment.
mintotni

Number defining the minimum number of samples allowed in the experiment.
maxgroupsize

Vector defining the max size of the different groups (max number of individuals in each group)
mingroupsize

Vector defining the min size of the different groups (min num individuals in each group) –
maxtotgroupsize

The total maximal groupsize over all groups
mintotgroupsize

The total minimal groupsize over all groups
maxxt

Matrix or single value defining the maximum value for each xt sample. If a single value is supplied then all xt values are given the same maximum value.
minxt

Matrix or single value defining the minimum value for each xt sample. If a single value is supplied then all xt values are given the same minimum value
discrete_xt

Cell array cell defining the discrete variables allowed for each xt value. Can also be a list of values list(1:10) (same values allowed for all xt), or a list of lists list(1:10, 2:23, 4:6) (one for each value in xt). See examples in create_design_space.
discrete_x

Cell array defining the discrete variables for each x value. See examples in create_design_space.
maxa

Vector defining the max value for each covariate. If a single value is supplied then all a values are given the same max value
mina

Vector defining the min value for each covariate. If a single value is supplied then all a values are given the same max value
discrete_a

Cell array cell defining the discrete variables allowed for each a value. Can also be a list of values list(1:10) (same values allowed for all a), or a list of lists list(1:10, 2:23, 4:6) (one for each value in a). See examples in create_design_space.
bUseGrouped_xt

Use grouped time points (1=TRUE, 0=FALSE).
G_xt

Matrix defining the grouping of sample points. Matching integers mean that the points are matched.
bUseGrouped_a

Use grouped covariates (1=TRUE, 0=FALSE)
G_a

Matrix defining the grouping of covariates. Matching integers mean that the points are matched.
bUseGrouped_x

Use grouped discrete design variables (1=TRUE, 0=FALSE).
G_x

Matrix defining the grouping of discrete design variables. Matching integers mean that the points are matched.
iFIMCalculationType

  • ******START OF FIM CALCULATION OPTIONS**********

Fisher Information Matrix type

  • 0=Full FIM

  • 1=Reduced FIM

  • 2=weighted models

  • 3=Loc models

  • 4=reduced FIM with derivative of SD of sigma as in PFIM

  • 5=FULL FIM parameterized with A,B,C matrices & derivative of variance

  • 6=Calculate one model switch at a time, good for large matrices

  • 7=Reduced FIM parameterized with A,B,C matrices & derivative of variance

iApproximationMethod

Approximation method for model, 0=FO, 1=FOCE, 2=FOCEI, 3=FOI
iFOCENumInd

Num individuals in each step of FOCE
prior_fim

The prior FIM (added to calculated FIM)
strAutoCorrelationFile

Filename and path, or function name, for the Autocorrelation function, empty string means no autocorrelation.
d_switch

  • ******START OF CRITERION SPECIFICATION OPTIONS**********

D-family design (1) or ED-family design (0) (with or without parameter uncertainty)
ofv_calc_type

OFV calculation type for FIM

  • 1 = "D-optimality". Determinant of the FIM: det(FIM)

  • 2 = "A-optimality". Inverse of the sum of the expected parameter variances: 1/trace_matrix(inv(FIM))

  • 4 = "lnD-optimality". Natural logarithm of the determinant of the FIM: log(det(FIM))

  • 6 = "Ds-optimality". Ratio of the Determinant of the FIM and the Determinant of the uninteresting rows and columns of the FIM: det(FIM)/det(FIM_u)

  • 7 = Inverse of the sum of the expected parameter RSE: 1/sum(get_rse(FIM,poped.db,use_percent=FALSE))

ds_index

Ds_index is a vector set to 1 if a parameter is uninteresting, otherwise 0. size=(1,num unfixed parameters). First unfixed bpop, then unfixed d, then unfixed docc and last unfixed sigma. Default is the fixed effects being important, everything else not important. Used in conjunction with ofv_calc_type=6.
strEDPenaltyFile

Penalty function name or path and filename, empty string means no penalty. User defined criterion can be defined this way.
ofv_fun

User defined function used to compute the objective function. The function must have a poped database object as its first argument and have "..." in its argument list. Can be referenced as a function or as a file name where the function defined in the file has the same name as the file. e.g. "cost.txt" has a function named "cost" in it.
iEDCalculationType

  • ******START OF E-FAMILY CRITERION SPECIFICATION OPTIONS**********

ED Integral Calculation, 0=Monte-Carlo-Integration, 1=Laplace Approximation, 2=BFGS Laplace Approximation – –
ED_samp_size

Sample size for E-family sampling
bLHS

How to sample from distributions in E-family calculations. 0=Random Sampling, 1=LatinHyperCube –
strUserDistributionFile

Filename and path, or function name, for user defined distributions for E-family designs
nbpop

  • ******START OF Model parameters SPECIFICATION OPTIONS**********

Number of typical values
NumRanEff

Number of IIV parameters. Typically can be computed from other values and not supplied.
NumDocc

Number of IOV variance parameters. Typically can be computed from other values and not supplied.
NumOcc

Number of occasions. Typically can be computed from other values and not supplied.
bpop

Matrix defining the fixed effects, per row (row number = parameter_number) we should have:

  • column 1 the type of the distribution for E-family designs (0 = Fixed, 1 = Normal, 2 = Uniform, 3 = User Defined Distribution, 4 = lognormal and 5 = truncated normal)

  • column 2 defines the mean.

  • column 3 defines the variance of the distribution (or length of uniform distribution).

Can also just supply the parameter values as a vector c() if no uncertainty around the parameter value is to be used. The parameter order of 'bpop' is defined in the 'fg_fun' or 'fg_file'. If you use named arguments in 'bpop' then the order of this vector can be rearranged to match the 'fg_fun' or 'fg_file'. See 'reorder_parameter_vectors'.
d

Matrix defining the diagonals of the IIV (same logic as for the fixed effects matrix bpop to define uncertainty). One can also just supply the parameter values as a c(). The parameter order of 'd' is defined in the 'fg_fun' or 'fg_file'. If you use named arguments in 'd' then the order of this vector can be rearranged to match the 'fg_fun' or 'fg_file'. See 'reorder_parameter_vectors'.
covd

Column major vector defining the covariances of the IIV variances. That is, from your full IIV matrix covd <- IIV[lower.tri(IIV)].
sigma

Matrix defining the variances can covariances of the residual variability terms of the model. can also just supply the diagonal parameter values (variances) as a c().
docc

Matrix defining the IOV, the IOV variances and the IOV distribution as for d and bpop.
covdocc

Column major vector defining the covariance of the IOV, as in covd.
notfixed_bpop

  • ******START OF Model parameters fixed or not SPECIFICATION OPTIONS**********

Vector defining if a typical value is fixed or not (1=not fixed, 0=fixed). The parameter order of 'notfixed_bpop' is defined in the 'fg_fun' or 'fg_file'. If you use named arguments in 'notfixed_bpop' then the order of this vector can be rearranged to match the 'fg_fun' or 'fg_file'. See 'reorder_parameter_vectors'.
notfixed_d

Vector defining if a IIV is fixed or not (1=not fixed, 0=fixed). The parameter order of 'notfixed_d' is defined in the 'fg_fun' or 'fg_file'. If you use named arguments in 'notfixed_d' then the order of this vector can be rearranged to match the 'fg_fun' or 'fg_file'. See 'reorder_parameter_vectors'. .
notfixed_covd

Vector defining if a covariance IIV is fixed or not (1=not fixed, 0=fixed)
notfixed_docc

Vector defining if an IOV variance is fixed or not (1=not fixed, 0=fixed)
notfixed_covdocc

Vector row major order for lower triangular matrix defining if a covariance IOV is fixed or not (1=not fixed, 0=fixed)
notfixed_sigma

Vector defining if a residual error parameter is fixed or not (1=not fixed, 0=fixed)
notfixed_covsigma

Vector defining if a covariance residual error parameter is fixed or not (1=not fixed, 0=fixed). Default is fixed.
reorder_parameter_vectors

If you use named arguments in 'bpop' or 'd' then PopED will try to figure out the order of the parameters based on what is found in the 'fg_fun'. See the resulting ‘poped_db$parameters' and make sure the order matches with ’fg_fun'.
bUseRandomSearch

  • ******START OF Optimization algorithm SPECIFICATION OPTIONS**********

Use random search (1=TRUE, 0=FALSE)
bUseStochasticGradient

Use Stochastic Gradient search (1=TRUE, 0=FALSE)
bUseLineSearch

Use Line search (1=TRUE, 0=FALSE)
bUseExchangeAlgorithm

Use Exchange algorithm (1=TRUE, 0=FALSE)
bUseBFGSMinimizer

Use BFGS Minimizer (1=TRUE, 0=FALSE)
EACriteria

Exchange Algorithm Criteria, 1 = Modified, 2 = Fedorov
strRunFile

Filename and path, or function name, for a run file that is used instead of the regular PopED call.
poped_version

  • ******START OF Labeling and file names SPECIFICATION OPTIONS**********

The current PopED version
modtit

The model title
output_file

Filename and path of the output file during search
output_function_file

Filename suffix of the result function file
strIterationFileName

Filename and path for storage of current optimal design
user_data

  • ******START OF Miscellaneous SPECIFICATION OPTIONS**********

User defined data structure that, for example could be used to send in data to the model
ourzero

Value to interpret as zero in design
dSeed

The seed number used for optimization and sampling – integer or -1 which creates a random seed as.integer(Sys.time()) or NULL.
line_opta

Vector for line search on continuous design variables (1=TRUE,0=FALSE)
line_optx

Vector for line search on discrete design variables (1=TRUE,0=FALSE)
bShowGraphs

Use graph output during search
use_logfile

If a log file should be used (0=FALSE, 1=TRUE)
m1_switch

Method used to calculate M1 (0=Complex difference, 1=Central difference, 20=Analytic derivative, 30=Automatic differentiation)
m2_switch

Method used to calculate M2 (0=Central difference, 1=Central difference, 20=Analytic derivative, 30=Automatic differentiation)
hle_switch

Method used to calculate linearization of residual error (0=Complex difference, 1=Central difference, 30=Automatic differentiation)
gradff_switch

Method used to calculate the gradient of the model (0=Complex difference, 1=Central difference, 20=Analytic derivative, 30=Automatic differentiation)
gradfg_switch

Method used to calculate the gradient of the parameter vector g (0=Complex difference, 1=Central difference, 20=Analytic derivative, 30=Automatic differentiation)
grad_all_switch

Method used to calculate all the gradients (0=Complex difference, 1=Central difference)
rsit_output

Number of iterations in random search between screen output
sgit_output

Number of iterations in stochastic gradient search between screen output
hm1

Step length of derivative of linearized model w.r.t. typical values
hlf

Step length of derivative of model w.r.t. g
hlg

Step length of derivative of g w.r.t. b
hm2

Step length of derivative of variance w.r.t. typical values
hgd

Step length of derivative of OFV w.r.t. time
hle

Step length of derivative of model w.r.t. sigma
AbsTol

The absolute tolerance for the diff equation solver
RelTol

The relative tolerance for the diff equation solver
iDiffSolverMethod

The diff equation solver method, NULL as default.
bUseMemorySolver

If the differential equation results should be stored in memory (1) or not (0)
rsit

Number of Random search iterations
sgit

Number of stochastic gradient iterations
intrsit

Number of Random search iterations with discrete optimization.
intsgit

Number of Stochastic Gradient search iterations with discrete optimization
maxrsnullit

Iterations until adaptive narrowing in random search
convergence_eps

Stochastic Gradient convergence value, (difference in OFV for D-optimal, difference in gradient for ED-optimal)
rslxt

Random search locality factor for sample times
rsla

Random search locality factor for covariates
cfaxt

Stochastic Gradient search first step factor for sample times
cfaa

Stochastic Gradient search first step factor for covariates
bGreedyGroupOpt

Use greedy algorithm for group assignment optimization
EAStepSize

Exchange Algorithm StepSize
EANumPoints

Exchange Algorithm NumPoints
EAConvergenceCriteria

Exchange Algorithm Convergence Limit/Criteria
bEANoReplicates

Avoid replicate samples when using Exchange Algorithm
BFGSConvergenceCriteriaMinStep

BFGS Minimizer Convergence Criteria Minimum Step
BFGSProjectedGradientTol

BFGS Minimizer Convergence Criteria Normalized Projected Gradient Tolerance
BFGSTolerancef

BFGS Minimizer Line Search Tolerance f
BFGSToleranceg

BFGS Minimizer Line Search Tolerance g
BFGSTolerancex

BFGS Minimizer Line Search Tolerance x
ED_diff_it

Number of iterations in ED-optimal design to calculate convergence criteria
ED_diff_percent

ED-optimal design convergence criteria in percent
line_search_it

Number of grid points in the line search
Doptim_iter

Number of iterations of full Random search and full Stochastic Gradient if line search is not used
iCompileOption

******START OF PARALLEL OPTIONS********** Compile options for PopED

  • -1 = No compilation,

  • 0 or 3 = Full compilation,

  • 1 or 4 = Only using MCC (shared lib),

  • 2 or 5 = Only MPI,

  • Option 0,1,2 runs PopED and option 3,4,5 stops after compilation

iUseParallelMethod

Parallel method to use (0 = Matlab PCT, 1 = MPI)
MCC_Dep

Additional dependencies used in MCC compilation (mat-files), if several space separated
strExecuteName

Compilation output executable name
iNumProcesses

Number of processes to use when running in parallel (e.g. 3 = 2 workers, 1 job manager)
iNumChunkDesignEvals

Number of design evaluations that should be evaluated in each process before getting new work from job manager
Mat_Out_Pre

The prefix of the output mat file to communicate with the executable
strExtraRunOptions

Extra options send to e$g. the MPI executable or a batch script, see execute_parallel$m for more information and options
dPollResultTime

Polling time to check if the parallel execution is finished
strFunctionInputName

The file containing the popedInput structure that should be used to evaluate the designs
bParallelRS

If the random search is going to be executed in parallel
bParallelSG

If the stochastic gradient search is going to be executed in parallel
bParallelMFEA

If the modified exchange algorithm is going to be executed in parallel
bParallelLS

If the line search is going to be executed in parallel

Value

A PopED database

See Also

Other poped_input: convert_variables(), create_design(), create_design_space(), downsizing_general_design(), poped.choose()

Examples

## Warfarin example from software comparison in:
## Nyberg et al., "Methods and software tools for design evaluation 
##   for population pharmacokinetics-pharmacodynamics studies", 
##   Br. J. Clin. Pharm., 2014. 

library(PopED)

## find the parameters that are needed to define from the structural model
ff.PK.1.comp.oral.md.CL

## -- parameter definition function 
## -- names match parameters in function ff
sfg <- function(x,a,bpop,b,bocc){
  parameters=c(CL=bpop[1]*exp(b[1]),
               V=bpop[2]*exp(b[2]),
               KA=bpop[3]*exp(b[3]),
               Favail=bpop[4],
               DOSE=a[1])
    return(parameters) 
}

## -- Define initial design  and design space
poped.db <- create.poped.database(
  ff_fun=ff.PK.1.comp.oral.sd.CL,
  fg_fun=sfg,
  fError_fun=feps.prop,
  bpop=c(CL=0.15, V=8, KA=1.0, Favail=1), 
  notfixed_bpop=c(1,1,1,0),
  d=c(CL=0.07, V=0.02, KA=0.6), 
  sigma=0.01,
  groupsize=32,
  xt=c( 0.5,1,2,6,24,36,72,120),
  minxt=0,
  maxxt=120,
  a=70)


## evaluate initial design
evaluate_design(poped.db)

Display a summary of output from poped_db

Description

Display a summary of output from poped_db

Usage

design_summary(poped_db, file = "", ...)

Arguments

poped_db

An object returned from create.poped.database to summarize.
file

A file handle to write to. Default is to the R console.
...

Additional arguments. Passed to blockfinal.

Compute efficiency.

Description

Efficiency calculation between two designs.

Usage

efficiency(
  ofv_init,
  ofv_final,
  poped_db,
  npar = get_fim_size(poped_db),
  ofv_calc_type = poped_db$settings$ofv_calc_type,
  ds_index = poped_db$parameters$ds_index,
  use_log = TRUE,
  ...
)

Arguments

ofv_init

An initial objective function
ofv_final

A final objective function.
poped_db

a poped database
npar

The number of parameters to use for normalization.
ofv_calc_type

OFV calculation type for FIM

  • 1 = "D-optimality". Determinant of the FIM: det(FIM)

  • 2 = "A-optimality". Inverse of the sum of the expected parameter variances: 1/trace_matrix(inv(FIM))

  • 4 = "lnD-optimality". Natural logarithm of the determinant of the FIM: log(det(FIM))

  • 6 = "Ds-optimality". Ratio of the Determinant of the FIM and the Determinant of the uninteresting rows and columns of the FIM: det(FIM)/det(FIM_u)

  • 7 = Inverse of the sum of the expected parameter RSE: 1/sum(get_rse(FIM,poped.db,use_percent=FALSE))

ds_index

Ds_index is a vector set to 1 if a parameter is uninteresting, otherwise 0. size=(1,num unfixed parameters). First unfixed bpop, then unfixed d, then unfixed docc and last unfixed sigma. Default is the fixed effects being important, everything else not important. Used in conjunction with ofv_calc_type=6.
use_log

Are the 'ofv' arguments in the log space?
...

arguments passed to evaluate.fim and ofv_fim.

Value

The specified efficiency value depending on the ofv_calc_type. The attribute "description" tells you how the calculation was made attr(return_vale,"description")

See Also

Other FIM: LinMatrixH(), LinMatrixLH(), LinMatrixL_occ(), calc_ofv_and_fim(), ed_laplace_ofv(), ed_mftot(), evaluate.e.ofv.fim(), evaluate.fim(), gradf_eps(), mf3(), mf7(), mftot(), ofv_criterion(), ofv_fim()

Evaluate a design

Description

This function evaluates the design defined in a poped database.

Usage

evaluate_design(poped.db, ...)

Arguments

poped.db

A poped database
...

Extra parameters passed to calc_ofv_and_fim and get_rse

Value

A list of elements evaluating the current design.

See Also

Other evaluate_design: evaluate.fim(), evaluate_power(), get_rse(), model_prediction(), plot_efficiency_of_windows(), plot_model_prediction()

Examples

library(PopED)

############# START #################
## Create PopED database
## (warfarin example)
#####################################

## Warfarin example from software comparison in:
## Nyberg et al., "Methods and software tools for design evaluation 
##   for population pharmacokinetics-pharmacodynamics studies", 
##   Br. J. Clin. Pharm., 2014. 

## find the parameters that are needed to define from the structural model
ff.PK.1.comp.oral.sd.CL

## -- parameter definition function 
## -- names match parameters in function ff
sfg <- function(x,a,bpop,b,bocc){
  parameters=c(CL=bpop[1]*exp(b[1]),
               V=bpop[2]*exp(b[2]),
               KA=bpop[3]*exp(b[3]),
               Favail=bpop[4],
               DOSE=a[1])
  return(parameters) 
}

## -- Define model, parameters, initial design
poped.db <- create.poped.database(ff_fun=ff.PK.1.comp.oral.sd.CL,
                                  fg_fun=sfg,
                                  fError_fun=feps.prop,
                                  bpop=c(CL=0.15, V=8, KA=1.0, Favail=1), 
                                  notfixed_bpop=c(1,1,1,0),
                                  d=c(CL=0.07, V=0.02, KA=0.6), 
                                  sigma=c(prop=0.01),
                                  groupsize=32,
                                  xt=c( 0.5,1,2,6,24,36,72,120),
                                  a=c(DOSE=70))

############# END ###################
## Create PopED database
## (warfarin example)
#####################################

evaluate_design(poped.db)

Compute the Bayesian Fisher information matrix

Description

Computation of the Bayesian Fisher information matrix for individual parameters of a population model based on Maximum A Posteriori (MAP) estimation of the empirical Bayes estimates (EBEs) in a population model

Usage

evaluate_fim_map(
  poped.db,
  use_mc = FALSE,
  num_sim_ids = 1000,
  use_purrr = FALSE,
  shrink_mat = F
)

Arguments

poped.db

A PopED database
use_mc

Should the calculation be based on monte-carlo simulations. If not then then a first order approximation is used
num_sim_ids

If use_mc=TRUE, how many individuals should be simulated to make the computations.
use_purrr

If use_mc=TRUE then should the method use the package purrr in calculations? This may speed up computations (potentially).
shrink_mat

Should the shrinkage matrix be returned. Calculated as the inverse of the Bayesian Fisher information matrix times the inverse of the omega matrix (variance matrix of the between-subject variability).

Value

The Bayesian Fisher information matrix for each design group

References

  1. Combes, F. P., Retout, S., Frey, N., & Mentre, F. (2013). Prediction of shrinkage of individual parameters using the Bayesian information matrix in non-linear mixed effect models with evaluation in pharmacokinetics. Pharmaceutical Research, 30(9), 2355-67. doi:10.1007/s11095-013-1079-3.

  2. Hennig, S., Nyberg, J., Fanta, S., Backman, J. T., Hoppu, K., Hooker, A. C., & Karlsson, M. O. (2012). Application of the optimal design approach to improve a pretransplant drug dose finding design for ciclosporin. Journal of Clinical Pharmacology, 52(3), 347-360. doi:10.1177/0091270010397731.

Examples

library(PopED)

############# START #################
## Create PopED database
## (warfarin example)
#####################################

## Warfarin example from software comparison in:
## Nyberg et al., "Methods and software tools for design evaluation 
##   for population pharmacokinetics-pharmacodynamics studies", 
##   Br. J. Clin. Pharm., 2014. 

## find the parameters that are needed to define from the structural model
ff.PK.1.comp.oral.sd.CL

## -- parameter definition function 
## -- names match parameters in function ff
sfg <- function(x,a,bpop,b,bocc){
  parameters=c(CL=bpop[1]*exp(b[1]),
               V=bpop[2]*exp(b[2]),
               KA=bpop[3]*exp(b[3]),
               Favail=bpop[4],
               DOSE=a[1])
  return(parameters) 
}

## -- Define model, parameters, initial design
poped.db <- create.poped.database(ff_fun=ff.PK.1.comp.oral.sd.CL,
                                  fg_fun=sfg,
                                  fError_fun=feps.prop,
                                  bpop=c(CL=0.15, V=8, KA=1.0, Favail=1), 
                                  notfixed_bpop=c(1,1,1,0),
                                  d=c(CL=0.07, V=0.02, KA=0.6), 
                                  sigma=c(prop=0.01),
                                  groupsize=32,
                                  xt=c( 0.5,1,2,6,24,36,72,120),
                                  a=c(DOSE=70))

############# END ###################
## Create PopED database
## (warfarin example)
#####################################

shrinkage(poped.db)

Power of a design to estimate a parameter.

Description

Evaluate the power of a design to estimate a parameter value different than some assumed value (often the assumed value is zero). The power is calculated using the linear Wald test and the the design is defined in a poped database.

Usage

evaluate_power(
  poped.db,
  bpop_idx,
  h0 = 0,
  alpha = 0.05,
  power = 0.8,
  twoSided = TRUE,
  find_min_n = TRUE,
  fim = NULL,
  out = NULL,
  ...
)

Arguments

poped.db

A poped database
bpop_idx

Index for an unfixed population parameter (bpop) for which the power should be evaluated for being different than the null hypothesis (h0).
h0

The null hypothesized value for the parameter.
alpha

Type 1 error.
power

Targeted power.
twoSided

Is this a two-sided test.
find_min_n

Should the function compute the minimum n needed (given the current design) to achieve the desired power?
fim

Provide the FIM from a previous calculation
out

provide output from a previous calculation (e.g., calc_ofv_and_fim, ...)
...

Extra parameters passed to calc_ofv_and_fim and get_rse

Value

A list of elements evaluating the current design including the power.

References

  1. Retout, S., Comets, E., Samson, A., and Mentre, F. (2007). Design in nonlinear mixed effects models: Optimization using the Fedorov-Wynn algorithm and power of the Wald test for binary covariates. Statistics in Medicine, 26(28), 5162-5179. doi:10.1002/sim.2910.

  2. Ueckert, S., Hennig, S., Nyberg, J., Karlsson, M. O., and Hooker, A. C. (2013). Optimizing disease progression study designs for drug effect discrimination. Journal of Pharmacokinetics and Pharmacodynamics, 40(5), 587-596. doi:10.1007/s10928-013-9331-3.

See Also

Other evaluate_design: evaluate.fim(), evaluate_design(), get_rse(), model_prediction(), plot_efficiency_of_windows(), plot_model_prediction()

Examples

# Folowing the examples presented in Retout, 2007

ff <- function(model_switch,xt,parameters,poped.db){
  with(as.list(parameters),{
    
    lambda1 <- lam1a
    if(TREAT==2) lambda1 <- lam1b
    
    y=log10(P1*exp(-lambda1*xt)+P2*exp(-lam2*xt))
    
    return(list(y=y,poped.db=poped.db))
  })
}

sfg <- function(x,a,bpop,b,bocc){
  parameters=c(P1=exp(bpop[1]+b[1]),
               P2=exp(bpop[2]+b[2]),
               lam1a=exp(bpop[3]+b[3]),
               lam1b=exp(bpop[3]+bpop[4]+b[3]),
               lam2=exp(bpop[5]+b[4]),
               TREAT=a[1])
  return(parameters) 
}
  

poped.db <- create.poped.database(ff_fun = ff,
                                  fg_fun = sfg,
                                  fError_fun = feps.add,
                                  bpop=c(P1=12, P2=8,
                                         lam1=-0.7,beta=0,lam2=-3.0),
                                  d=c(P1=0.3, P2=0.3,
                                      lam1=0.3,lam2=0.3), 
                                  sigma=c(0.065^2),
                                  groupsize=100,
                                  m=2,
                                  xt=c(1, 3, 7, 14, 28, 56),
                                  minxt=0,
                                  maxxt=100,
                                  a=list(c(TREAT=1),c(TREAT=2)))

plot_model_prediction(poped.db)
evaluate_design(poped.db)

poped.db_2 <- create.poped.database(poped.db,bpop=c(P1=12, P2=8,
                                      lam1=-0.7,beta=0.262,lam2=-3.0))

plot_model_prediction(poped.db_2)
evaluate_design(poped.db_2)

evaluate_power(poped.db_2,bpop_idx = 4)

Evaluate the expectation of the Fisher Information Matrix (FIM) and the expectation of the OFV(FIM).

Description

Compute the expectation of the FIM and OFV(FIM) given the model, parameters, distributions of parameter uncertainty, design and methods defined in the PopED database. Some of the arguments coming from the PopED database can be overwritten; by default these arguments are NULL in the function, if they are supplied then they are used instead of the arguments from the PopED database.

Usage

evaluate.e.ofv.fim(
  poped.db,
  fim.calc.type = NULL,
  bpop = poped.db$parameters$bpop,
  d = poped.db$parameters$d,
  covd = poped.db$parameters$covd,
  docc = poped.db$parameters$docc,
  sigma = poped.db$parameters$sigma,
  model_switch = NULL,
  ni = NULL,
  xt = NULL,
  x = NULL,
  a = NULL,
  groupsize = poped.db$design$groupsize,
  deriv.type = NULL,
  bLHS = poped.db$settings$bLHS,
  ofv_calc_type = poped.db$settings$ofv_calc_type,
  ED_samp_size = poped.db$settings$ED_samp_size,
  use_laplace = poped.db$settings$iEDCalculationType,
  laplace.fim = FALSE,
  ...
)

Arguments

poped.db

A PopED database.
fim.calc.type

The method used for calculating the FIM. Potential values:

  • 0 = Full FIM. No assumption that fixed and random effects are uncorrelated.

  • 1 = Reduced FIM. Assume that there is no correlation in the FIM between the fixed and random effects, and set these elements in the FIM to zero.

  • 2 = weighted models (placeholder).

  • 3 = Not currently used.

  • 4 = Reduced FIM and computing all derivatives with respect to the standard deviation of the residual unexplained variation (sqrt(SIGMA) in NONMEM). This matches what is done in PFIM, and assumes that the standard deviation of the residual unexplained variation is the estimated parameter (NOTE: NONMEM estimates the variance of the residual unexplained variation by default).

  • 5 = Full FIM parameterized with A,B,C matrices & derivative of variance.

  • 6 = Calculate one model switch at a time, good for large matrices.

  • 7 = Reduced FIM parameterized with A,B,C matrices & derivative of variance.

bpop

Matrix defining the fixed effects, per row (row number = parameter_number) we should have:

  • column 1 the type of the distribution for E-family designs (0 = Fixed, 1 = Normal, 2 = Uniform, 3 = User Defined Distribution, 4 = lognormal and 5 = truncated normal)

  • column 2 defines the mean.

  • column 3 defines the variance of the distribution (or length of uniform distribution).

Can also just supply the parameter values as a vector c() if no uncertainty around the parameter value is to be used. The parameter order of 'bpop' is defined in the 'fg_fun' or 'fg_file'. If you use named arguments in 'bpop' then the order of this vector can be rearranged to match the 'fg_fun' or 'fg_file'. See 'reorder_parameter_vectors'.
d

Matrix defining the diagonals of the IIV (same logic as for the fixed effects matrix bpop to define uncertainty). One can also just supply the parameter values as a c(). The parameter order of 'd' is defined in the 'fg_fun' or 'fg_file'. If you use named arguments in 'd' then the order of this vector can be rearranged to match the 'fg_fun' or 'fg_file'. See 'reorder_parameter_vectors'.
covd

Column major vector defining the covariances of the IIV variances. That is, from your full IIV matrix covd <- IIV[lower.tri(IIV)].
docc

Matrix defining the IOV, the IOV variances and the IOV distribution as for d and bpop.
sigma

Matrix defining the variances can covariances of the residual variability terms of the model. can also just supply the diagonal parameter values (variances) as a c().
model_switch

A matrix that is the same size as xt, specifying which model each sample belongs to.
ni

A vector of the number of samples in each group.
xt

A matrix of sample times. Each row is a vector of sample times for a group.
x

A matrix for the discrete design variables. Each row is a group.
a

A matrix of covariates. Each row is a group.
groupsize

A vector of the number of individuals in each group.
deriv.type

A number indicating the type of derivative to use:

  • 0=Complex difference

  • 1=Central difference

  • 20=Analytic derivative (placeholder)

  • 30=Automatic differentiation (placeholder)

bLHS

How to sample from distributions in E-family calculations. 0=Random Sampling, 1=LatinHyperCube –
ofv_calc_type

OFV calculation type for FIM

  • 1 = "D-optimality". Determinant of the FIM: det(FIM)

  • 2 = "A-optimality". Inverse of the sum of the expected parameter variances: 1/trace_matrix(inv(FIM))

  • 4 = "lnD-optimality". Natural logarithm of the determinant of the FIM: log(det(FIM))

  • 6 = "Ds-optimality". Ratio of the Determinant of the FIM and the Determinant of the uninteresting rows and columns of the FIM: det(FIM)/det(FIM_u)

  • 7 = Inverse of the sum of the expected parameter RSE: 1/sum(get_rse(FIM,poped.db,use_percent=FALSE))

ED_samp_size

Sample size for E-family sampling
use_laplace

Should the Laplace method be used in calculating the expectation of the OFV?
laplace.fim

Should an E(FIM) be calculated when computing the Laplace approximated E(OFV). Typically the FIM does not need to be computed and, if desired, this calculation is done using the standard MC integration technique, so can be slow.
...

Other arguments passed to the function.

Value

A list containing the E(FIM) and E(OFV(FIM)) and the a poped.db updated according to the function arguments.

See Also

Other FIM: LinMatrixH(), LinMatrixLH(), LinMatrixL_occ(), calc_ofv_and_fim(), ed_laplace_ofv(), ed_mftot(), efficiency(), evaluate.fim(), gradf_eps(), mf3(), mf7(), mftot(), ofv_criterion(), ofv_fim()

Other E-family: calc_ofv_and_fim(), ed_laplace_ofv(), ed_mftot()

Other evaluate_FIM: calc_ofv_and_fim(), evaluate.fim(), ofv_fim()

Examples

library(PopED)

############# START #################
## Create PopED database
## (warfarin model for optimization
##  with parameter uncertainty)
#####################################

## Warfarin example from software comparison in:
## Nyberg et al., "Methods and software tools for design evaluation 
##   for population pharmacokinetics-pharmacodynamics studies", 
##   Br. J. Clin. Pharm., 2014. 

## Optimization using an additive + proportional reidual error
## to avoid sample times at very low concentrations (time 0 or very late samoples).

## find the parameters that are needed to define from the structural model
ff.PK.1.comp.oral.sd.CL

## -- parameter definition function 
## -- names match parameters in function ff
sfg <- function(x,a,bpop,b,bocc){
  parameters=c(CL=bpop[1]*exp(b[1]),
               V=bpop[2]*exp(b[2]),
               KA=bpop[3]*exp(b[3]),
               Favail=bpop[4],
               DOSE=a[1])
  return(parameters) 
}

# Adding 10% log-normal Uncertainty to fixed effects (not Favail)
bpop_vals <- c(CL=0.15, V=8, KA=1.0, Favail=1)
bpop_vals_ed_ln <- cbind(ones(length(bpop_vals),1)*4, # log-normal distribution
                         bpop_vals,
                         ones(length(bpop_vals),1)*(bpop_vals*0.1)^2) # 10% of bpop value
bpop_vals_ed_ln["Favail",]  <- c(0,1,0)
bpop_vals_ed_ln

## -- Define initial design  and design space
poped.db <- create.poped.database(ff_fun=ff.PK.1.comp.oral.sd.CL,
                                  fg_fun=sfg,
                                  fError_fun=feps.add.prop,
                                  bpop=bpop_vals_ed_ln, 
                                  notfixed_bpop=c(1,1,1,0),
                                  d=c(CL=0.07, V=0.02, KA=0.6), 
                                  sigma=c(0.01,0.25),
                                  groupsize=32,
                                  xt=c( 0.5,1,2,6,24,36,72,120),
                                  minxt=0,
                                  maxxt=120,
                                  a=70,
                                  mina=0,
                                  maxa=100)

############# END ###################
## Create PopED database
## (warfarin model for optimization
##  with parameter uncertainty)
#####################################


## ED evaluate (with very few samples)
output <- evaluate.e.ofv.fim(poped.db,ED_samp_size=10)
output$E_ofv

## API evaluate (with very few samples)
output <- evaluate.e.ofv.fim(poped.db,ED_samp_size=10,ofv_calc_type=4)
output$E_ofv

## ED evaluate using Laplace approximation 
tic()
output <- evaluate.e.ofv.fim(poped.db,use_laplace=TRUE)
toc()
output$E_ofv

## Not run: 

  ## ED expected value with more precision. 
  ## Compare time and value to Laplace approximation.
  ## Run a couple of times to see stochasticity of calculation.
  tic()
  e_ofv_mc <- evaluate.e.ofv.fim(poped.db,ED_samp_size=500)
  toc()
  e_ofv_mc$E_ofv
  
  # If you want to get an E(FIM) from the laplace approximation you have to ask for it
  # and it will take more time.
  output <- evaluate.e.ofv.fim(poped.db,use_laplace=TRUE,laplace.fim=TRUE)
  output$E_fim
  
 


## End(Not run)

Evaluate the Fisher Information Matrix (FIM)

Description

Compute the FIM given the model, parameters, design and methods defined in the PopED database. Some of the arguments coming from the PopED database can be overwritten; by default these arguments are NULL in the function, if they are supplied then they are used instead of the arguments from the PopED database.

Usage

evaluate.fim(
  poped.db,
  fim.calc.type = NULL,
  approx.method = NULL,
  FOCE.num = NULL,
  bpop.val = NULL,
  d_full = NULL,
  docc_full = NULL,
  sigma_full = NULL,
  model_switch = NULL,
  ni = NULL,
  xt = NULL,
  x = NULL,
  a = NULL,
  groupsize = NULL,
  deriv.type = NULL,
  ...
)

Arguments

poped.db

A PopED database.
fim.calc.type

The method used for calculating the FIM. Potential values:

  • 0 = Full FIM. No assumption that fixed and random effects are uncorrelated.

  • 1 = Reduced FIM. Assume that there is no correlation in the FIM between the fixed and random effects, and set these elements in the FIM to zero.

  • 2 = weighted models (placeholder).

  • 3 = Not currently used.

  • 4 = Reduced FIM and computing all derivatives with respect to the standard deviation of the residual unexplained variation (sqrt(SIGMA) in NONMEM). This matches what is done in PFIM, and assumes that the standard deviation of the residual unexplained variation is the estimated parameter (NOTE: NONMEM estimates the variance of the residual unexplained variation by default).

  • 5 = Full FIM parameterized with A,B,C matrices & derivative of variance.

  • 6 = Calculate one model switch at a time, good for large matrices.

  • 7 = Reduced FIM parameterized with A,B,C matrices & derivative of variance.

approx.method

Approximation method for model, 0=FO, 1=FOCE, 2=FOCEI, 3=FOI
FOCE.num

Number individuals in each step of FOCE approximation method
bpop.val

The fixed effects parameter values. Supplied as a vector.
d_full

A between subject variability matrix (OMEGA in NONMEM).
docc_full

A between occasion variability matrix.
sigma_full

A residual unexplained variability matrix (SIGMA in NONMEM).
model_switch

A matrix that is the same size as xt, specifying which model each sample belongs to.
ni

A vector of the number of samples in each group.
xt

A matrix of sample times. Each row is a vector of sample times for a group.
x

A matrix for the discrete design variables. Each row is a group.
a

A matrix of covariates. Each row is a group.
groupsize

A vector of the number of individuals in each group.
deriv.type

A number indicating the type of derivative to use:

  • 0=Complex difference

  • 1=Central difference

  • 20=Analytic derivative (placeholder)

  • 30=Automatic differentiation (placeholder)

...

Other arguments passed to the function.

Value

The FIM.

See Also

Other FIM: LinMatrixH(), LinMatrixLH(), LinMatrixL_occ(), calc_ofv_and_fim(), ed_laplace_ofv(), ed_mftot(), efficiency(), evaluate.e.ofv.fim(), gradf_eps(), mf3(), mf7(), mftot(), ofv_criterion(), ofv_fim()

Other evaluate_design: evaluate_design(), evaluate_power(), get_rse(), model_prediction(), plot_efficiency_of_windows(), plot_model_prediction()

Other evaluate_FIM: calc_ofv_and_fim(), evaluate.e.ofv.fim(), ofv_fim()

Examples

## Warfarin example from software comparison in:
## Nyberg et al., "Methods and software tools for design evaluation 
##   for population pharmacokinetics-pharmacodynamics studies", 
##   Br. J. Clin. Pharm., 2014. 

library(PopED)

## find the parameters that are needed to define from the structural model
ff.PK.1.comp.oral.md.CL

## -- parameter definition function 
## -- names match parameters in function ff
sfg <- function(x,a,bpop,b,bocc){
  parameters=c(CL=bpop[1]*exp(b[1]),
               V=bpop[2]*exp(b[2]),
               KA=bpop[3]*exp(b[3]),
               Favail=bpop[4],
               DOSE=a[1])
    return(parameters) 
}

## -- Define initial design  and design space
poped.db <- create.poped.database(ff_fun = ff.PK.1.comp.oral.sd.CL,
                                  fg_fun = sfg,
                                  fError_fun = feps.prop,
                                  bpop=c(CL=0.15, V=8, KA=1.0, Favail=1), 
                                  # notfixed_bpop=c(1,1,1,0),
                                  notfixed_bpop=c(CL=1,V=1,KA=1,Favail=0),
                                  d=c(CL=0.07, V=0.02, KA=0.6), 
                                  sigma=0.01,
                                  groupsize=32,
                                  xt=c( 0.5,1,2,6,24,36,72,120),
                                  minxt=0,
                                  maxxt=120,
                                  a=70)


## evaluate initial design with the reduced FIM
FIM.1 <- evaluate.fim(poped.db) 
FIM.1
det(FIM.1)
det(FIM.1)^(1/7)
get_rse(FIM.1,poped.db)

## evaluate initial design with the full FIM
FIM.0 <- evaluate.fim(poped.db,fim.calc.type=0) 
FIM.0
det(FIM.0)
det(FIM.0)^(1/7)
get_rse(FIM.0,poped.db)

## evaluate initial design with the reduced FIM 
## computing all derivatives with respect to the 
## standard deviation of the residual unexplained variation 
FIM.4 <- evaluate.fim(poped.db,fim.calc.type=4) 
FIM.4
det(FIM.4)
get_rse(FIM.4,poped.db,fim.calc.type=4)

## evaluate initial design with the full FIM with A,B,C matricies
## should give same answer as fim.calc.type=0
FIM.5 <- evaluate.fim(poped.db,fim.calc.type=5) 
FIM.5
det(FIM.5)
get_rse(FIM.5,poped.db,fim.calc.type=5)

## evaluate initial design with the reduced FIM with 
## A,B,C matricies and derivative of variance
## should give same answer as fim.calc.type=1 (default)
FIM.7 <- evaluate.fim(poped.db,fim.calc.type=7) 
FIM.7
det(FIM.7)
get_rse(FIM.7,poped.db,fim.calc.type=7)

## evaluate FIM and rse with prior FIM.1
poped.db.prior = create.poped.database(poped.db, prior_fim = FIM.1)
FIM.1.prior <- evaluate.fim(poped.db.prior)
all.equal(FIM.1.prior,FIM.1) # the FIM is only computed from the design in the poped.db
get_rse(FIM.1.prior,poped.db.prior) # the RSE is computed with the prior information

RUV model: Additive .

Description

This is a residual unexplained variability (RUV) model function that encodes the model described above. The function is suitable for input to the create.poped.database function using the fError_file argument.

Usage

feps.add(model_switch, xt, parameters, epsi, poped.db)

Arguments

model_switch

a vector of values, the same size as xt, identifying which model response should be computed for the corresponding xt value. Used for multiple response models.
xt

a vector of independent variable values (often time).
parameters

A named list of parameter values.
epsi

A matrix with the same number of rows as the xt vector, columns match the numbers defined in this function.
poped.db

a poped database. This can be used to extract information that may be needed in the model file.

Value

A list consisting of:

  1. y the values of the model at the specified points.

  2. poped.db A (potentially modified) poped database.

See Also

Other models: feps.add.prop(), feps.prop(), ff.PK.1.comp.oral.md.CL(), ff.PK.1.comp.oral.md.KE(), ff.PK.1.comp.oral.sd.CL(), ff.PK.1.comp.oral.sd.KE(), ff.PKPD.1.comp.oral.md.CL.imax(), ff.PKPD.1.comp.sd.CL.emax()

Other RUV_models: feps.add.prop(), feps.prop()

Examples

library(PopED)

## find the parameters that are needed to define from the structural model
ff.PK.1.comp.oral.sd.KE

## -- parameter definition function 
## -- names match parameters in function ff
sfg <- function(x,a,bpop,b,bocc){
  parameters=c(KE=bpop[1]*exp(b[1]),
               V=bpop[2]*exp(b[2]),
               KA=bpop[3]*exp(b[3]),
               Favail=bpop[4],
               DOSE=a[1])
  return(parameters) 
}

## -- Define initial design  and design space
poped.db <- create.poped.database(ff_fun=ff.PK.1.comp.oral.sd.KE,
                                  fg_fun=sfg,
                                  fError_fun=feps.add,
                                  bpop=c(KE=0.15/8, V=8, KA=1.0, Favail=1), 
                                  notfixed_bpop=c(1,1,1,0),
                                  d=c(KE=0.07, V=0.02, KA=0.6), 
                                  sigma=1,
                                  groupsize=32,
                                  xt=c( 0.5,1,2,6,24,36,72,120),
                                  minxt=0,
                                  maxxt=120,
                                  a=70)

##  create plot of model without variability 
plot_model_prediction(poped.db)

## evaluate initial design
FIM <- evaluate.fim(poped.db) 
FIM
det(FIM)
get_rse(FIM,poped.db)

RUV model: Additive and Proportional.

Description

This is a residual unexplained variability (RUV) model function that encodes the model described above. The function is suitable for input to the create.poped.database function using the fError_file argument.

Usage

feps.add.prop(model_switch, xt, parameters, epsi, poped.db)

Arguments

model_switch

a vector of values, the same size as xt, identifying which model response should be computed for the corresponding xt value. Used for multiple response models.
xt

a vector of independent variable values (often time).
parameters

A named list of parameter values.
epsi

A matrix with the same number of rows as the xt vector, columns match the numbers defined in this function.
poped.db

a poped database. This can be used to extract information that may be needed in the model file.

Value

A list consisting of:

  1. y the values of the model at the specified points.

  2. poped.db A (potentially modified) poped database.

See Also

Other models: feps.add(), feps.prop(), ff.PK.1.comp.oral.md.CL(), ff.PK.1.comp.oral.md.KE(), ff.PK.1.comp.oral.sd.CL(), ff.PK.1.comp.oral.sd.KE(), ff.PKPD.1.comp.oral.md.CL.imax(), ff.PKPD.1.comp.sd.CL.emax()

Other RUV_models: feps.add(), feps.prop()

Examples

library(PopED)

## find the parameters that are needed to define in the structural model
ff.PK.1.comp.oral.md.CL

## -- parameter definition function 
## -- names match parameters in function ff
sfg <- function(x,a,bpop,b,bocc){
  parameters=c( V=bpop[1]*exp(b[1]),
                KA=bpop[2]*exp(b[2]),
                CL=bpop[3]*exp(b[3]),
                Favail=bpop[4],
                DOSE=a[1],
                TAU=a[2])
  return( parameters ) 
}

## -- Define design and design space
poped.db <- create.poped.database(ff_fun=ff.PK.1.comp.oral.md.CL,
                                  fg_fun=sfg,
                                  fError_fun=feps.add.prop,
                                  groupsize=20,
                                  m=2,
                                  sigma=c(0.04,5e-6),
                                  bpop=c(V=72.8,KA=0.25,CL=3.75,Favail=0.9), 
                                  d=c(V=0.09,KA=0.09,CL=0.25^2), 
                                  notfixed_bpop=c(1,1,1,0),
                                  notfixed_sigma=c(0,0),
                                  xt=c( 1,2,8,240,245),
                                  minxt=c(0,0,0,240,240),
                                  maxxt=c(10,10,10,248,248),
                                  a=cbind(c(20,40),c(24,24)),
                                  bUseGrouped_xt=1,
                                  maxa=c(200,24),
                                  mina=c(0,24))

##  create plot of model without variability 
plot_model_prediction(poped.db)

## evaluate initial design
FIM <- evaluate.fim(poped.db) 
FIM
det(FIM)
get_rse(FIM,poped.db)

RUV model: Proportional.

Description

This is a residual unexplained variability (RUV) model function that encodes the model described above. The function is suitable for input to the create.poped.database function using the fError_file argument.

Usage

feps.prop(model_switch, xt, parameters, epsi, poped.db)

Arguments

model_switch

a vector of values, the same size as xt, identifying which model response should be computed for the corresponding xt value. Used for multiple response models.
xt

a vector of independent variable values (often time).
parameters

A named list of parameter values.
epsi

A matrix with the same number of rows as the xt vector, columns match the numbers defined in this function.
poped.db

a poped database. This can be used to extract information that may be needed in the model file.

Value

A list consisting of:

  1. y the values of the model at the specified points.

  2. poped.db A (potentially modified) poped database.

See Also

Other models: feps.add(), feps.add.prop(), ff.PK.1.comp.oral.md.CL(), ff.PK.1.comp.oral.md.KE(), ff.PK.1.comp.oral.sd.CL(), ff.PK.1.comp.oral.sd.KE(), ff.PKPD.1.comp.oral.md.CL.imax(), ff.PKPD.1.comp.sd.CL.emax()

Other RUV_models: feps.add(), feps.add.prop()

Examples

library(PopED)

############# START #################
## Create PopED database
## (warfarin example)
#####################################

## Warfarin example from software comparison in:
## Nyberg et al., "Methods and software tools for design evaluation 
##   for population pharmacokinetics-pharmacodynamics studies", 
##   Br. J. Clin. Pharm., 2014. 

## find the parameters that are needed to define from the structural model
ff.PK.1.comp.oral.sd.CL

## -- parameter definition function 
## -- names match parameters in function ff
sfg <- function(x,a,bpop,b,bocc){
  parameters=c(CL=bpop[1]*exp(b[1]),
               V=bpop[2]*exp(b[2]),
               KA=bpop[3]*exp(b[3]),
               Favail=bpop[4],
               DOSE=a[1])
  return(parameters) 
}

## -- Define model, parameters, initial design
poped.db <- create.poped.database(ff_fun=ff.PK.1.comp.oral.sd.CL,
                                  fg_fun=sfg,
                                  fError_fun=feps.prop,
                                  bpop=c(CL=0.15, V=8, KA=1.0, Favail=1), 
                                  notfixed_bpop=c(1,1,1,0),
                                  d=c(CL=0.07, V=0.02, KA=0.6), 
                                  sigma=c(prop=0.01),
                                  groupsize=32,
                                  xt=c( 0.5,1,2,6,24,36,72,120),
                                  a=c(DOSE=70))

############# END ###################
## Create PopED database
## (warfarin example)
#####################################


##  create plot of model without variability 
plot_model_prediction(poped.db)

## evaluate initial design
FIM <- evaluate.fim(poped.db) 
FIM
det(FIM)
get_rse(FIM,poped.db)

Structural model: one-compartment, oral absorption, multiple bolus dose, parameterized using CL.

Description

This is a structural model function that encodes a model that is one-compartment, oral absorption, multiple bolus dose, parameterized using CL. The function is suitable for input to the create.poped.database function using the ff_fun or ff_file argument.

Usage

ff.PK.1.comp.oral.md.CL(model_switch, xt, parameters, poped.db)

Arguments

model_switch

a vector of values, the same size as xt, identifying which model response should be computed for the corresponding xt value. Used for multiple response models.
xt

a vector of independent variable values (often time).
parameters

A named list of parameter values.
poped.db

a poped database. This can be used to extract information that may be needed in the model file.

Value

A list consisting of:

  1. y the values of the model at the specified points.

  2. poped.db A (potentially modified) poped database.

See Also

Other models: feps.add(), feps.add.prop(), feps.prop(), ff.PK.1.comp.oral.md.KE(), ff.PK.1.comp.oral.sd.CL(), ff.PK.1.comp.oral.sd.KE(), ff.PKPD.1.comp.oral.md.CL.imax(), ff.PKPD.1.comp.sd.CL.emax()

Other structural_models: ff.PK.1.comp.oral.md.KE(), ff.PK.1.comp.oral.sd.CL(), ff.PK.1.comp.oral.sd.KE(), ff.PKPD.1.comp.oral.md.CL.imax(), ff.PKPD.1.comp.sd.CL.emax()

Examples

library(PopED)

## find the parameters that are needed to define in the structural model
ff.PK.1.comp.oral.md.CL

## -- parameter definition function 
## -- names match parameters in function ff
sfg <- function(x,a,bpop,b,bocc){
  parameters=c( V=bpop[1]*exp(b[1]),
                KA=bpop[2]*exp(b[2]),
                CL=bpop[3]*exp(b[3]),
                Favail=bpop[4],
                DOSE=a[1],
                TAU=a[2])
  return( parameters ) 
}

## -- Define design and design space
poped.db <- create.poped.database(ff_fun=ff.PK.1.comp.oral.md.CL,
                                  fg_fun=sfg,
                                  fError_fun=feps.add.prop,
                                  groupsize=20,
                                  m=2,
                                  sigma=c(0.04,5e-6),
                                  bpop=c(V=72.8,KA=0.25,CL=3.75,Favail=0.9), 
                                  d=c(V=0.09,KA=0.09,CL=0.25^2), 
                                  notfixed_bpop=c(1,1,1,0),
                                  notfixed_sigma=c(0,0),
                                  xt=c( 1,2,8,240,245),
                                  minxt=c(0,0,0,240,240),
                                  maxxt=c(10,10,10,248,248),
                                  a=cbind(c(20,40),c(24,24)),
                                  bUseGrouped_xt=1,
                                  maxa=c(200,24),
                                  mina=c(0,24))

##  create plot of model without variability 
plot_model_prediction(poped.db)

## evaluate initial design
FIM <- evaluate.fim(poped.db) 
FIM
det(FIM)
get_rse(FIM,poped.db)

Structural model: one-compartment, oral absorption, multiple bolus dose, parameterized using KE.

Description

This is a structural model function that encodes a model that is one-compartment, oral absorption, multiple bolus dose, parameterized using KE. The function is suitable for input to the create.poped.database function using the ff_fun or ff_file argument.

Usage

ff.PK.1.comp.oral.md.KE(model_switch, xt, parameters, poped.db)

Arguments

model_switch

a vector of values, the same size as xt, identifying which model response should be computed for the corresponding xt value. Used for multiple response models.
xt

a vector of independent variable values (often time).
parameters

A named list of parameter values.
poped.db

a poped database. This can be used to extract information that may be needed in the model file.

Value

A list consisting of:

  1. y the values of the model at the specified points.

  2. poped.db A (potentially modified) poped database.

See Also

Other models: feps.add(), feps.add.prop(), feps.prop(), ff.PK.1.comp.oral.md.CL(), ff.PK.1.comp.oral.sd.CL(), ff.PK.1.comp.oral.sd.KE(), ff.PKPD.1.comp.oral.md.CL.imax(), ff.PKPD.1.comp.sd.CL.emax()

Other structural_models: ff.PK.1.comp.oral.md.CL(), ff.PK.1.comp.oral.sd.CL(), ff.PK.1.comp.oral.sd.KE(), ff.PKPD.1.comp.oral.md.CL.imax(), ff.PKPD.1.comp.sd.CL.emax()

Examples

library(PopED)

## find the parameters that are needed to define in the structural model
ff.PK.1.comp.oral.md.KE

## -- parameter definition function 
## -- names match parameters in function ff
sfg <- function(x,a,bpop,b,bocc){
  ## -- parameter definition function 
  parameters=c( V=bpop[1]*exp(b[1]),
                KA=bpop[2]*exp(b[2]), 
                KE=bpop[3]*exp(b[3]),
                Favail=bpop[4],
                DOSE=a[1],
                TAU=a[2])
  return( parameters ) 
}

## -- Define design and design space
poped.db <- create.poped.database(ff_fun=ff.PK.1.comp.oral.md.KE,
                                  fg_fun=sfg,
                                  fError_fun=feps.add.prop,
                                  groupsize=20,
                                  m=2,
                                  sigma=c(0.04,5e-6),
                                  bpop=c(V=72.8,KA=0.25,KE=3.75/72.8,Favail=0.9), 
                                  d=c(V=0.09,KA=0.09,KE=0.25^2), 
                                  notfixed_bpop=c(1,1,1,0),
                                  notfixed_sigma=c(0,0),
                                  xt=c( 1,2,8,240,245),
                                  minxt=c(0,0,0,240,240),
                                  maxxt=c(10,10,10,248,248),
                                  a=cbind(c(20,40),c(24,24)),
                                  bUseGrouped_xt=1,
                                  maxa=c(200,40),
                                  mina=c(0,2))

##  create plot of model without variability 
plot_model_prediction(poped.db)

## evaluate initial design
FIM <- evaluate.fim(poped.db) 
FIM
det(FIM)
get_rse(FIM,poped.db)

Structural model: one-compartment, oral absorption, single bolus dose, parameterized using CL.

Description

This is a structural model function that encodes a model that is one-compartment, oral absorption, single bolus dose, parameterized using CL. The function is suitable for input to the create.poped.database function using the ff_fun or ff_file argument.

Usage

ff.PK.1.comp.oral.sd.CL(model_switch, xt, parameters, poped.db)

Arguments

model_switch

a vector of values, the same size as xt, identifying which model response should be computed for the corresponding xt value. Used for multiple response models.
xt

a vector of independent variable values (often time).
parameters

A named list of parameter values.
poped.db

a poped database. This can be used to extract information that may be needed in the model file.

Value

A list consisting of:

  1. y the values of the model at the specified points.

  2. poped.db A (potentially modified) poped database.

See Also

Other models: feps.add(), feps.add.prop(), feps.prop(), ff.PK.1.comp.oral.md.CL(), ff.PK.1.comp.oral.md.KE(), ff.PK.1.comp.oral.sd.KE(), ff.PKPD.1.comp.oral.md.CL.imax(), ff.PKPD.1.comp.sd.CL.emax()

Other structural_models: ff.PK.1.comp.oral.md.CL(), ff.PK.1.comp.oral.md.KE(), ff.PK.1.comp.oral.sd.KE(), ff.PKPD.1.comp.oral.md.CL.imax(), ff.PKPD.1.comp.sd.CL.emax()

Examples

library(PopED)

############# START #################
## Create PopED database
## (warfarin example)
#####################################

## Warfarin example from software comparison in:
## Nyberg et al., "Methods and software tools for design evaluation 
##   for population pharmacokinetics-pharmacodynamics studies", 
##   Br. J. Clin. Pharm., 2014. 

## find the parameters that are needed to define from the structural model
ff.PK.1.comp.oral.sd.CL

## -- parameter definition function 
## -- names match parameters in function ff
sfg <- function(x,a,bpop,b,bocc){
  parameters=c(CL=bpop[1]*exp(b[1]),
               V=bpop[2]*exp(b[2]),
               KA=bpop[3]*exp(b[3]),
               Favail=bpop[4],
               DOSE=a[1])
  return(parameters) 
}

## -- Define model, parameters, initial design
poped.db <- create.poped.database(ff_fun=ff.PK.1.comp.oral.sd.CL,
                                  fg_fun=sfg,
                                  fError_fun=feps.prop,
                                  bpop=c(CL=0.15, V=8, KA=1.0, Favail=1), 
                                  notfixed_bpop=c(1,1,1,0),
                                  d=c(CL=0.07, V=0.02, KA=0.6), 
                                  sigma=c(prop=0.01),
                                  groupsize=32,
                                  xt=c( 0.5,1,2,6,24,36,72,120),
                                  a=c(DOSE=70))

############# END ###################
## Create PopED database
## (warfarin example)
#####################################


##  create plot of model without variability 
plot_model_prediction(poped.db)

## evaluate initial design
FIM <- evaluate.fim(poped.db) 
FIM
det(FIM)
get_rse(FIM,poped.db)

Structural model: one-compartment, oral absorption, single bolus dose, parameterized using KE.

Description

This is a structural model function that encodes a model that is one-compartment, oral absorption, single bolus dose, parameterized using KE. The function is suitable for input to the create.poped.database function using the ff_fun or ff_file argument.

Usage

ff.PK.1.comp.oral.sd.KE(model_switch, xt, parameters, poped.db)

Arguments

model_switch

a vector of values, the same size as xt, identifying which model response should be computed for the corresponding xt value. Used for multiple response models.
xt

a vector of independent variable values (often time).
parameters

A named list of parameter values.
poped.db

a poped database. This can be used to extract information that may be needed in the model file.

Value

A list consisting of:

  1. y the values of the model at the specified points.

  2. poped.db A (potentially modified) poped database.

See Also

Other models: feps.add(), feps.add.prop(), feps.prop(), ff.PK.1.comp.oral.md.CL(), ff.PK.1.comp.oral.md.KE(), ff.PK.1.comp.oral.sd.CL(), ff.PKPD.1.comp.oral.md.CL.imax(), ff.PKPD.1.comp.sd.CL.emax()

Other structural_models: ff.PK.1.comp.oral.md.CL(), ff.PK.1.comp.oral.md.KE(), ff.PK.1.comp.oral.sd.CL(), ff.PKPD.1.comp.oral.md.CL.imax(), ff.PKPD.1.comp.sd.CL.emax()

Examples

library(PopED)

## find the parameters that are needed to define from the structural model
ff.PK.1.comp.oral.sd.KE

## -- parameter definition function 
## -- names match parameters in function ff
sfg <- function(x,a,bpop,b,bocc){
  parameters=c(KE=bpop[1]*exp(b[1]),
               V=bpop[2]*exp(b[2]),
               KA=bpop[3]*exp(b[3]),
               Favail=bpop[4],
               DOSE=a[1])
  return(parameters) 
}

## -- Define initial design  and design space
poped.db <- create.poped.database(ff_fun=ff.PK.1.comp.oral.sd.KE,
                                  fg_fun=sfg,
                                  fError_fun=feps.prop,
                                  bpop=c(KE=0.15/8, V=8, KA=1.0, Favail=1), 
                                  notfixed_bpop=c(1,1,1,0),
                                  d=c(KE=0.07, V=0.02, KA=0.6), 
                                  sigma=0.01,
                                  groupsize=32,
                                  xt=c( 0.5,1,2,6,24,36,72,120),
                                  minxt=0,
                                  maxxt=120,
                                  a=70)

##  create plot of model without variability 
plot_model_prediction(poped.db)

## evaluate initial design
FIM <- evaluate.fim(poped.db) 
FIM
det(FIM)
get_rse(FIM,poped.db)

Structural model: one-compartment, oral absorption, multiple bolus dose, parameterized using CL driving an inhibitory IMAX model with a direct effect.

Description

This is a structural model function that encodes the model described above. The function is suitable for input to the create.poped.database function using the ff_fun or ff_file argument.

Usage

ff.PKPD.1.comp.oral.md.CL.imax(model_switch, xt, parameters, poped.db)

Arguments

model_switch

a vector of values, the same size as xt, identifying which model response should be computed for the corresponding xt value. Used for multiple response models.
xt

a vector of independent variable values (often time).
parameters

A named list of parameter values.
poped.db

a poped database. This can be used to extract information that may be needed in the model file.

Value

A list consisting of:

  1. y the values of the model at the specified points.

  2. poped.db A (potentially modified) poped database.

See Also

Other models: feps.add(), feps.add.prop(), feps.prop(), ff.PK.1.comp.oral.md.CL(), ff.PK.1.comp.oral.md.KE(), ff.PK.1.comp.oral.sd.CL(), ff.PK.1.comp.oral.sd.KE(), ff.PKPD.1.comp.sd.CL.emax()

Other structural_models: ff.PK.1.comp.oral.md.CL(), ff.PK.1.comp.oral.md.KE(), ff.PK.1.comp.oral.sd.CL(), ff.PK.1.comp.oral.sd.KE(), ff.PKPD.1.comp.sd.CL.emax()

Examples

library(PopED)

## find the parameters that are needed to define from the structural model
ff.PKPD.1.comp.oral.md.CL.imax
ff.PK.1.comp.oral.md.CL

## -- parameter definition function 
## -- names match parameters in function ff
sfg <- function(x,a,bpop,b,bocc){
  ## -- parameter definition function 
  parameters=c( V=bpop[1]*exp(b[1]),
                KA=bpop[2]*exp(b[2]),
                CL=bpop[3]*exp(b[3]),
                Favail=bpop[4],
                DOSE=a[1],
                TAU = a[2],
                E0=bpop[5]*exp(b[4]),
                IMAX=bpop[6],
                IC50=bpop[7])
  return( parameters ) 
}



feps <- function(model_switch,xt,parameters,epsi,poped.db){
  ## -- Residual Error function
  returnArgs <- do.call(poped.db$model$ff_pointer,list(model_switch,xt,parameters,poped.db)) 
  y <- returnArgs[[1]]
  poped.db <- returnArgs[[2]]
  
  MS <- model_switch
  
  pk.dv <- y*(1+epsi[,1])+epsi[,2]
  pd.dv <-  y*(1+epsi[,3])+epsi[,4]
  
  y[MS==1] = pk.dv[MS==1]
  y[MS==2] = pd.dv[MS==2]
  
  return(list( y= y,poped.db =poped.db )) 
}


## -- Define initial design  and design space
poped.db <- create.poped.database(ff_fun=ff.PKPD.1.comp.oral.md.CL.imax,
                                  fError_fun=feps,
                                  fg_fun=sfg,
                                  groupsize=20,
                                  m=3,
                                  bpop=c(V=72.8,KA=0.25,CL=3.75,Favail=0.9,
                                         E0=1120,IMAX=0.807,IC50=0.0993),  
                                  notfixed_bpop=c(1,1,1,0,1,1,1),
                                  d=c(V=0.09,KA=0.09,CL=0.25^2,E0=0.09), 
                                  sigma=c(0.04,5e-6,0.09,100),
                                  notfixed_sigma=c(0,0,0,0),
                                  xt=c( 1,2,8,240,240,1,2,8,240,240),
                                  minxt=c(0,0,0,240,240,0,0,0,240,240),
                                  maxxt=c(10,10,10,248,248,10,10,10,248,248),
                                  G_xt=c(1,2,3,4,5,1,2,3,4,5),
                                  model_switch=c(1,1,1,1,1,2,2,2,2,2),
                                  a=cbind(c(20,40,0),c(24,24,24)),
                                  bUseGrouped_xt=1,
                                  ourzero=0,
                                  maxa=c(200,40),
                                  mina=c(0,2))


##  create plot of model without variability 
plot_model_prediction(poped.db,facet_scales="free")

## evaluate initial design
FIM <- evaluate.fim(poped.db) 
FIM
det(FIM)
get_rse(FIM,poped.db)

Structural model: one-compartment, single bolus IV dose, parameterized using CL driving an EMAX model with a direct effect.

Description

This is a structural model function that encodes the model described above. The function is suitable for input to the create.poped.database function using the ff_fun or ff_file argument.

Usage

ff.PKPD.1.comp.sd.CL.emax(model_switch, xt, parameters, poped.db)

Arguments

model_switch

a vector of values, the same size as xt, identifying which model response should be computed for the corresponding xt value. Used for multiple response models.
xt

a vector of independent variable values (often time).
parameters

A named list of parameter values.
poped.db

a poped database. This can be used to extract information that may be needed in the model file.

Value

A list consisting of:

  1. y the values of the model at the specified points.

  2. poped.db A (potentially modified) poped database.

See Also

Other models: feps.add(), feps.add.prop(), feps.prop(), ff.PK.1.comp.oral.md.CL(), ff.PK.1.comp.oral.md.KE(), ff.PK.1.comp.oral.sd.CL(), ff.PK.1.comp.oral.sd.KE(), ff.PKPD.1.comp.oral.md.CL.imax()

Other structural_models: ff.PK.1.comp.oral.md.CL(), ff.PK.1.comp.oral.md.KE(), ff.PK.1.comp.oral.sd.CL(), ff.PK.1.comp.oral.sd.KE(), ff.PKPD.1.comp.oral.md.CL.imax()

Examples

library(PopED)

## find the parameters that are needed to define from the structural model
ff.PKPD.1.comp.sd.CL.emax

## -- parameter definition function 
## -- names match parameters in function ff
sfg <- function(x,a,bpop,b,bocc){
  ## -- parameter definition function
  parameters=c( 
    CL=bpop[1]*exp(b[1])  ,
    V=bpop[2]*exp(b[2])  ,
    E0=bpop[3]*exp(b[3])  ,
    EMAX=bpop[4]*exp(b[4])	,
    EC50=bpop[5]*exp(b[5])	,
    DOSE=a[1]
  )
  return( parameters ) 
}

feps <- function(model_switch,xt,parameters,epsi,poped.db){
  ## -- Residual Error function
  ## -- Proportional PK + additive PD
  returnArgs <- do.call(poped.db$model$ff_pointer,list(model_switch,xt,parameters,poped.db)) 
  y <- returnArgs[[1]]
  poped.db <- returnArgs[[2]]
  
  MS <- model_switch
  
  prop.err <- y*(1+epsi[,1])
  add.err <- y+epsi[,2]
  
  y[MS==1] = prop.err[MS==1]
  y[MS==2] = add.err[MS==2]
  
  return(list( y= y,poped.db =poped.db )) 
}

## -- Define initial design  and design space
poped.db <- create.poped.database(ff_fun=ff.PKPD.1.comp.sd.CL.emax,
                                  fError_fun=feps,
                                  fg_fun=sfg,
                                  groupsize=20,
                                  m=3,
                                  sigma=diag(c(0.15,0.15)),
                                  bpop=c(CL=0.5,V=0.2,E0=1,EMAX=1,EC50=1),  
                                  d=c(CL=0.01,V=0.01,E0=0.01,EMAX=0.01,EC50=0.01), 
                                  xt=c( 0.33,0.66,0.9,5,0.1,1,2,5),
                                  model_switch=c( 1,1,1,1,2,2,2,2),
                                  minxt=0,
                                  maxxt=5,
                                  a=rbind(2.75,5,10),
                                  bUseGrouped_xt=1,
                                  maxa=10,
                                  mina=0.1)


##  create plot of model without variability 
plot_model_prediction(poped.db,facet_scales="free")

## evaluate initial design
FIM <- evaluate.fim(poped.db) 
FIM
det(FIM)
get_rse(FIM,poped.db)

Compute the expected parameter relative standard errors

Description

This function computes the expected relative standard errors of a model given a design and a previously computed FIM.

Usage

get_rse(
  fim,
  poped.db,
  bpop = poped.db$parameters$bpop[, 2],
  d = poped.db$parameters$d[, 2],
  docc = poped.db$parameters$docc,
  sigma = poped.db$parameters$sigma,
  use_percent = TRUE,
  fim.calc.type = poped.db$settings$iFIMCalculationType,
  prior_fim = poped.db$settings$prior_fim,
  ...
)

Arguments

fim

A Fisher Information Matrix (FIM).
poped.db

A PopED database.
bpop

A vector containing the values of the fixed effects used to compute the fim.
d

A vector containing the values of the diagonals of the between subject variability matrix.
docc

Matrix defining the IOV, the IOV variances and the IOV distribution as for d and bpop.
sigma

Matrix defining the variances can covariances of the residual variability terms of the model. can also just supply the diagonal parameter values (variances) as a c().
use_percent

Should RSE be reported as percent?
fim.calc.type

The method used for calculating the FIM. Potential values:

  • 0 = Full FIM. No assumption that fixed and random effects are uncorrelated.

  • 1 = Reduced FIM. Assume that there is no correlation in the FIM between the fixed and random effects, and set these elements in the FIM to zero.

  • 2 = weighted models (placeholder).

  • 3 = Not currently used.

  • 4 = Reduced FIM and computing all derivatives with respect to the standard deviation of the residual unexplained variation (sqrt(SIGMA) in NONMEM). This matches what is done in PFIM, and assumes that the standard deviation of the residual unexplained variation is the estimated parameter (NOTE: NONMEM estimates the variance of the residual unexplained variation by default).

  • 5 = Full FIM parameterized with A,B,C matrices & derivative of variance.

  • 6 = Calculate one model switch at a time, good for large matrices.

  • 7 = Reduced FIM parameterized with A,B,C matrices & derivative of variance.

prior_fim

A prior FIM to be added to the fim. Should be the same size as the fim.
...

Additional arguments passed to inv.

Value

A named list of RSE values. If the estimated parameter is assumed to be zero then for that parameter the standard error is returned.

See Also

Other evaluate_design: evaluate.fim(), evaluate_design(), evaluate_power(), model_prediction(), plot_efficiency_of_windows(), plot_model_prediction()

Examples

## Warfarin example from software comparison in:
## Nyberg et al., "Methods and software tools for design evaluation 
##   for population pharmacokinetics-pharmacodynamics studies", 
##   Br. J. Clin. Pharm., 2014. 

library(PopED)

## find the parameters that are needed to define from the structural model
ff.PK.1.comp.oral.md.CL

## -- parameter definition function 
## -- names match parameters in function ff
sfg <- function(x,a,bpop,b,bocc){
  parameters=c(CL=bpop[1]*exp(b[1]),
               V=bpop[2]*exp(b[2]),
               KA=bpop[3]*exp(b[3]),
               Favail=bpop[4],
               DOSE=a[1])
    return(parameters) 
}

## -- Define initial design  and design space
poped.db <- create.poped.database(ff_fun = ff.PK.1.comp.oral.sd.CL,
                                  fg_fun = sfg,
                                  fError_fun = feps.prop,
                                  bpop=c(CL=0.15, V=8, KA=1.0, Favail=1), 
                                  # notfixed_bpop=c(1,1,1,0),
                                  notfixed_bpop=c(CL=1,V=1,KA=1,Favail=0),
                                  d=c(CL=0.07, V=0.02, KA=0.6), 
                                  sigma=0.01,
                                  groupsize=32,
                                  xt=c( 0.5,1,2,6,24,36,72,120),
                                  minxt=0,
                                  maxxt=120,
                                  a=70)


## evaluate initial design with the reduced FIM
FIM.1 <- evaluate.fim(poped.db) 
FIM.1
det(FIM.1)
det(FIM.1)^(1/7)
get_rse(FIM.1,poped.db)

## evaluate initial design with the full FIM
FIM.0 <- evaluate.fim(poped.db,fim.calc.type=0) 
FIM.0
det(FIM.0)
det(FIM.0)^(1/7)
get_rse(FIM.0,poped.db)

## evaluate initial design with the reduced FIM 
## computing all derivatives with respect to the 
## standard deviation of the residual unexplained variation 
FIM.4 <- evaluate.fim(poped.db,fim.calc.type=4) 
FIM.4
det(FIM.4)
get_rse(FIM.4,poped.db,fim.calc.type=4)

## evaluate initial design with the full FIM with A,B,C matricies
## should give same answer as fim.calc.type=0
FIM.5 <- evaluate.fim(poped.db,fim.calc.type=5) 
FIM.5
det(FIM.5)
get_rse(FIM.5,poped.db,fim.calc.type=5)

## evaluate initial design with the reduced FIM with 
## A,B,C matricies and derivative of variance
## should give same answer as fim.calc.type=1 (default)
FIM.7 <- evaluate.fim(poped.db,fim.calc.type=7) 
FIM.7
det(FIM.7)
get_rse(FIM.7,poped.db,fim.calc.type=7)

## evaluate FIM and rse with prior FIM.1
poped.db.prior = create.poped.database(poped.db, prior_fim = FIM.1)
FIM.1.prior <- evaluate.fim(poped.db.prior)
all.equal(FIM.1.prior,FIM.1) # the FIM is only computed from the design in the poped.db
get_rse(FIM.1.prior,poped.db.prior) # the RSE is computed with the prior information

Optimization function for D-family, E-family and Laplace approximated ED designs

Description

Optimize the objective function for D-family, E-family and Laplace approximated ED designs. Right now there is only one optimization algorithm used in this function

  1. Adaptive random search. See RS_opt.

This function takes information from the PopED database supplied as an argument. The PopED database supplies information about the the model, parameters, design and methods to use. Some of the arguments coming from the PopED database can be overwritten; if they are supplied then they are used instead of the arguments from the PopED database.

Usage

LEDoptim(
  poped.db,
  model_switch = NULL,
  ni = NULL,
  xt = NULL,
  x = NULL,
  a = NULL,
  bpopdescr = NULL,
  ddescr = NULL,
  maxxt = NULL,
  minxt = NULL,
  maxa = NULL,
  mina = NULL,
  ofv_init = 0,
  fim_init = 0,
  trflag = TRUE,
  header_flag = TRUE,
  footer_flag = TRUE,
  opt_xt = poped.db$settings$optsw[2],
  opt_a = poped.db$settings$optsw[4],
  opt_x = poped.db$settings$optsw[3],
  out_file = NULL,
  d_switch = FALSE,
  use_laplace = T,
  laplace.fim = FALSE,
  use_RS = poped.db$settings$bUseRandomSearch,
  ...
)

Arguments

poped.db

A PopED database.
model_switch

A matrix that is the same size as xt, specifying which model each sample belongs to.
ni

A vector of the number of samples in each group.
xt

A matrix of sample times. Each row is a vector of sample times for a group.
x

A matrix for the discrete design variables. Each row is a group.
a

A matrix of covariates. Each row is a group.
bpopdescr

Matrix defining the fixed effects, per row (row number = parameter_number) we should have:

  • column 1 the type of the distribution for E-family designs (0 = Fixed, 1 = Normal, 2 = Uniform, 3 = User Defined Distribution, 4 = lognormal and 5 = truncated normal)

  • column 2 defines the mean.

  • column 3 defines the variance of the distribution (or length of uniform distribution).

ddescr

Matrix defining the diagonals of the IIV (same logic as for the bpopdescr).
maxxt

Matrix or single value defining the maximum value for each xt sample. If a single value is supplied then all xt values are given the same maximum value.
minxt

Matrix or single value defining the minimum value for each xt sample. If a single value is supplied then all xt values are given the same minimum value
maxa

Vector defining the max value for each covariate. If a single value is supplied then all a values are given the same max value
mina

Vector defining the min value for each covariate. If a single value is supplied then all a values are given the same max value
ofv_init

The initial OFV. If set to zero then it is computed.
fim_init

The initial value of the FIM. If set to zero then it is computed.
trflag

Should the optimization be output to the screen and to a file?
header_flag

Should the header text be printed out?
footer_flag

Should the footer text be printed out?
opt_xt

Should the sample times be optimized?
opt_a

Should the continuous design variables be optimized?
opt_x

Should the discrete design variables be optimized?
out_file

Which file should the output be directed to? A string, a file handle using file or "" will output to the screen.
d_switch

  • ******START OF CRITERION SPECIFICATION OPTIONS**********

D-family design (1) or ED-family design (0) (with or without parameter uncertainty)
use_laplace

Should the Laplace method be used in calculating the expectation of the OFV?
laplace.fim

Should an E(FIM) be calculated when computing the Laplace approximated E(OFV). Typically the FIM does not need to be computed and, if desired, this calculation is done using the standard MC integration technique, so can be slow.
use_RS

should the function use a random search algorithm?
...

arguments passed to evaluate.fim and ofv_fim.

See Also

Other Optimize: Doptim(), RS_opt(), a_line_search(), bfgsb_min(), calc_autofocus(), calc_ofv_and_grad(), mfea(), optim_ARS(), optim_LS(), poped_optim(), poped_optim_1(), poped_optim_2(), poped_optim_3(), poped_optimize()

Examples

library(PopED)

############# START #################
## Create PopED database
## (warfarin model for optimization
##  with parameter uncertainty)
#####################################

## Warfarin example from software comparison in:
## Nyberg et al., "Methods and software tools for design evaluation 
##   for population pharmacokinetics-pharmacodynamics studies", 
##   Br. J. Clin. Pharm., 2014. 

## Optimization using an additive + proportional reidual error
## to avoid sample times at very low concentrations (time 0 or very late samoples).

## find the parameters that are needed to define from the structural model
ff.PK.1.comp.oral.sd.CL

## -- parameter definition function 
## -- names match parameters in function ff
sfg <- function(x,a,bpop,b,bocc){
  parameters=c(CL=bpop[1]*exp(b[1]),
               V=bpop[2]*exp(b[2]),
               KA=bpop[3]*exp(b[3]),
               Favail=bpop[4],
               DOSE=a[1])
  return(parameters) 
}

# Adding 10% log-normal Uncertainty to fixed effects (not Favail)
bpop_vals <- c(CL=0.15, V=8, KA=1.0, Favail=1)
bpop_vals_ed_ln <- cbind(ones(length(bpop_vals),1)*4, # log-normal distribution
                         bpop_vals,
                         ones(length(bpop_vals),1)*(bpop_vals*0.1)^2) # 10% of bpop value
bpop_vals_ed_ln["Favail",]  <- c(0,1,0)
bpop_vals_ed_ln

## -- Define initial design  and design space
poped.db <- create.poped.database(ff_fun=ff.PK.1.comp.oral.sd.CL,
                                  fg_fun=sfg,
                                  fError_fun=feps.add.prop,
                                  bpop=bpop_vals_ed_ln, 
                                  notfixed_bpop=c(1,1,1,0),
                                  d=c(CL=0.07, V=0.02, KA=0.6), 
                                  sigma=c(0.01,0.25),
                                  groupsize=32,
                                  xt=c( 0.5,1,2,6,24,36,72,120),
                                  minxt=0,
                                  maxxt=120,
                                  a=70,
                                  mina=0,
                                  maxa=100)

############# END ###################
## Create PopED database
## (warfarin model for optimization
##  with parameter uncertainty)
#####################################

# warfarin ed model

## Not run: 
  
  LEDoptim(poped.db) 
  
  LEDoptim(poped.db,opt_xt=T,rsit=10) 
  
  LEDoptim(poped.db,opt_xt=T,rsit=10,d_switch=TRUE) 

  LEDoptim(poped.db,opt_xt=T,rsit=10,laplace.fim=TRUE) 
  
  LEDoptim(poped.db,opt_xt=T,rsit=10,use_laplace=FALSE) 
  
  ## testing header and footer
  LEDoptim(poped.db,opt_xt=T,rsit=10,d_switch=TRUE,
           out_file="foobar.txt") 
  
  ff <- LEDoptim(poped.db,opt_xt=T,rsit=10,d_switch=TRUE,
                 trflag=FALSE) 
  
  LEDoptim(poped.db,opt_xt=T,rsit=10,d_switch=TRUE,
           header_flag=FALSE) 
  
  LEDoptim(poped.db,opt_xt=T,rsit=10,d_switch=TRUE,
           out_file="") 
  
  LEDoptim(poped.db,opt_xt=T,rsit=10,d_switch=TRUE,
           footer_flag=FALSE) 
  
  LEDoptim(poped.db,opt_xt=T,rsit=10,d_switch=TRUE,
           footer_flag=FALSE, header_flag=FALSE) 
  
  LEDoptim(poped.db,opt_xt=T,rsit=10,d_switch=TRUE,
           footer_flag=FALSE, header_flag=FALSE,out_file="foobar.txt") 
  
  LEDoptim(poped.db,opt_xt=T,rsit=10,d_switch=TRUE,
           footer_flag=FALSE, header_flag=FALSE,out_file="") 


## End(Not run)

Compute the monte-carlo mean of a function

Description

Function computes the monte-carlo mean of a function by varying the parameter inputs to the function

Usage

mc_mean(
  ofv_fcn,
  poped.db,
  bpopdescr = poped.db$parameters$bpop,
  ddescr = poped.db$parameters$d,
  doccdescr = poped.db$parameters$d,
  user_distribution_pointer = poped.db$model$user_distribution_pointer,
  ED_samp_size = poped.db$settings$ED_samp_size,
  bLHS = poped.db$settings$bLHS,
  ...
)

Arguments

ofv_fcn

A function with poped.db as the first input
poped.db

A PopED database.
bpopdescr

Matrix defining the fixed effects, per row (row number = parameter_number) we should have:

  • column 1 the type of the distribution for E-family designs (0 = Fixed, 1 = Normal, 2 = Uniform, 3 = User Defined Distribution, 4 = lognormal and 5 = truncated normal)

  • column 2 defines the mean.

  • column 3 defines the variance of the distribution (or length of uniform distribution).

ddescr

Matrix defining the diagonals of the IIV (same logic as for the bpopdescr).
doccdescr

Matrix defining the IOV. per row (row number = parameter_number) we should have:

  • column 1 the type of the distribution for E-family designs (0 = Fixed, 1 = Normal, 2 = Uniform, 3 = User Defined Distribution, 4 = lognormal and 5 = truncated normal)

  • column 2 defines the mean of the variance.

  • column 3 defines the variance of the distribution (or length of uniform distribution).

user_distribution_pointer

Function name for user defined distributions for E-family designs
ED_samp_size

Sample size for E-family sampling
bLHS

How to sample from distributions in E-family calculations. 0=Random Sampling, 1=LatinHyperCube –
...

Other arguments passed to the function.

Value

The mean of the function evaluated at different parameter values.

Wrap summary functions from Hmisc and ggplot to work with stat_summary in ggplot

Description

Created for back compatibility with older versions of ggplot, and so that PopED does not have to load ggplot when started.

Usage

median_hilow_poped(x, ...)

Arguments

x

A numeric vector
...

Additional arguments passed to Hmisc's smedian.hilow function or ggplot2's median_hilow function, depending on your version of ggplot.

Model predictions

Description

Function generates a data frame of model predictions for the typical value in the population, individual predictions and data predictions. The function can also be used to generate datasets without predictions using the design specified in the arguments.

Usage

model_prediction(
  poped.db = NULL,
  design = list(xt = poped.db$design[["xt"]], groupsize = poped.db$design$groupsize, m =
    poped.db$design[["m"]], x = poped.db$design[["x"]], a = poped.db$design[["a"]], ni =
    poped.db$design$ni, model_switch = poped.db$design$model_switch),
  model = list(fg_pointer = poped.db$model$fg_pointer, ff_pointer =
    poped.db$model$ff_pointer, ferror_pointer = poped.db$model$ferror_pointer),
  parameters = list(docc = poped.db$parameters$docc, d = poped.db$parameters$d, bpop =
    poped.db$parameters$bpop, covd = poped.db$parameters$covd, covdocc =
    poped.db$parameters$covdocc, sigma = poped.db$parameters$sigma),
  IPRED = FALSE,
  DV = FALSE,
  dosing = NULL,
  predictions = NULL,
  filename = NULL,
  models_to_use = "all",
  model_num_points = NULL,
  model_minxt = NULL,
  model_maxxt = NULL,
  include_sample_times = T,
  groups_to_use = "all",
  include_a = TRUE,
  include_x = TRUE,
  manipulation = NULL,
  PI = FALSE,
  PI_conf_level = 0.95,
  PI_ln_dist = TRUE
)

Arguments

poped.db

A PopED database created by create.poped.database.
design

A list that is passed as arguments to the function create_design to create a design object.
model

A list containing the model elements to use for the predictions
parameters

A list of parameters to use in the model predictions.
IPRED

Should we simulate individual predictions?
DV

should we simulate observations?
dosing

A list of lists that adds dosing records to the data frame (Each inner list corresponding to a group in the design).
predictions

Should the resulting data frame have predictions? Either TRUE or FALSE or NULL in which case the function decides based on other arguments.
filename

A filename that the data frame should be written to in comma separate value (csv) format.
models_to_use

Which model numbers should we use? Model numbers are defined in design below using model_switch. For an explanation see create_design.
model_num_points

How many extra observation rows should be created in the data frame for each group or individual per model. If used then the points are placed evenly between model_minxt and model_maxxt. This option is used by plot_model_prediction to simulate the response of the model on a finer grid then the defined design. If NULL then only the input design is used. Can be a single value or a vector the same length as the number of models.
model_minxt

The minimum time value for extra observation rows indicated by model_num_points. A vector the same length as the number of models
model_maxxt

The minimum time value for extra observation rows indicated by model_num_points. A vector the same length as the number of models
include_sample_times

Should observations rows in the output data frame include the times indicated in the input design?
groups_to_use

Which groups should we include in the output data frame?Allowed values are "all" or a vector of numbers indicating the groups to include, e.g. c(1,3,6).
include_a

Should we include the continuous design variables in the output?
include_x

Should we include the discrete design variables in the output?
manipulation

A list of one or more expression arguments. Each expression is evaluated using the code for(i in 1:length(manipulation)){df <- within(df,{eval(manipulation[[i]])})}. Can be used to transform or create new columns in the resulting data frame. Note that these transformations are created after any model predictions occur, so transformations in columns having to do with input to model predictions will not affect the predictions.
PI

Compute prediction intervals for the data given the model. Predictions are based on first-order approximations to the model variance and a log-normality assumption of that variance (by default), if all predictions are positive, otherwise a normal distribution is assumed.
PI_conf_level

The confidence level for the prediction interval computed.
PI_ln_dist

Should the PI calculation be done assuming log-normal or a normal distribution. TRUE is the default and indicates a log-normal distribution. If any of the PRED values from the model are negative then a normal distribution is assumed.

Value

A dataframe containing a design and (potentially) simulated data with some dense grid of samples and/or based on the input design.

See Also

Other evaluate_design: evaluate.fim(), evaluate_design(), evaluate_power(), get_rse(), plot_efficiency_of_windows(), plot_model_prediction()

Other Simulation: plot_efficiency_of_windows(), plot_model_prediction()

Examples

## Warfarin example from software comparison in:
## Nyberg et al., "Methods and software tools for design evaluation 
##   for population pharmacokinetics-pharmacodynamics studies", 
##   Br. J. Clin. Pharm., 2014. 

library(PopED)

## find the parameters that are needed to define from the structural model
ff.PK.1.comp.oral.md.CL

## -- parameter definition function 
## -- names match parameters in function ff
sfg <- function(x,a,bpop,b,bocc){
  parameters=c(CL=bpop[1]*exp(b[1]),
               V=bpop[2]*exp(b[2]),
               KA=bpop[3]*exp(b[3]),
               Favail=bpop[4],
               DOSE=a[1])
    return(parameters) 
}

## -- Define initial design  and design space
poped.db <- create.poped.database(ff_fun=ff.PK.1.comp.oral.sd.CL,
                                  fg_fun=sfg,
                                  fError_fun=feps.prop,
                                  bpop=c(CL=0.15, V=8, KA=1.0, Favail=1), 
                                  notfixed_bpop=c(1,1,1,0),
                                  d=c(CL=0.07, V=0.02, KA=0.6), 
                                  sigma=0.01,
                                  groupsize=32,
                                  xt=c( 0.5,1,2,6,24,36,72,120),
                                  minxt=0,
                                  maxxt=120,
                                  a=70)

## data frame with model predictions
df_1 <- model_prediction(poped.db)
head(df_1,n=20)

##  data frame with variability 
df_2 <- model_prediction(poped.db,DV=TRUE)
head(df_2,n=20)

## data frame with variability (only IPRED, no DV)
df_3 <- model_prediction(poped.db,IPRED=TRUE)
head(df_3,n=20)

## data frame with model predictions, no continuous design variables in data frame
df_4 <- model_prediction(poped.db,include_a = FALSE)
head(df_4,n=20)

## -- 2 groups
poped.db.2 <- create.poped.database(ff_fun=ff.PK.1.comp.oral.sd.CL,
                                    fg_fun=sfg,
                                    fError_fun=feps.prop,
                                    bpop=c(CL=0.15, V=8, KA=1.0, Favail=1), 
                                    notfixed_bpop=c(1,1,1,0),
                                    d=c(CL=0.07, V=0.02, KA=0.6), 
                                    sigma=0.01,
                                    groupsize=rbind(3,3),
                                    m=2,
                                    xt=c( 0.5,1,2,6,24,36,72,120),
                                    minxt=0,
                                    maxxt=120,
                                    a=rbind(70,50))

df_5 <- model_prediction(poped.db.2,DV=TRUE)
head(df_5,n=20)

## without a poped database, just describing the design
## Useful for creating datasets for use in other software (like NONMEM)
design_1 <- list(
  xt=c( 0.5,1,2,6,24,36,72,120),
  m=2,
  groupsize=3)

design_2 <- list(
  xt=c( 0.5,1,2,6,24,36,72,120),
  m=2,
  groupsize=3,
  a=c(WT=70,AGE=50))

design_3 <- list(
  xt=c( 0.5,1,2,6,24,36,72,120),
  m=2,
  groupsize=3,
  a=list(c(WT=70,AGE=50),c(AGE=45,WT=60)))

(df_6 <- model_prediction(design=design_1))
(df_7 <- model_prediction(design=design_2))
(df_8 <- model_prediction(design=design_3))
(df_9 <- model_prediction(design=design_3,DV=TRUE))

# generate random deviations in WT for each individual
df_10 <- model_prediction(design=design_3,DV=TRUE,
                          manipulation=expression({for(id in unique(ID)) 
                              WT[ID==id] = rnorm(1,WT[ID==id],WT[ID==id]*0.1);id <- NULL}))
head(df_10,n=20)

# generate random deviations in WT and AGE for each individual
df_11 <- model_prediction(design=design_3,DV=TRUE,
                          manipulation=list(
                            expression(for(id in unique(ID)) 
                              WT[ID==id] = rnorm(1,WT[ID==id],WT[ID==id]*0.1)),
                            expression(for(id in unique(ID)) 
                              AGE[ID==id] = rnorm(1,AGE[ID==id],AGE[ID==id]*0.2)),
                            expression(id <- NULL)
                          ))
head(df_10,n=20)

## create dosing rows 
dosing_1 <- list(list(AMT=1000,RATE=NA,Time=0.5),list(AMT=3000,RATE=NA,Time=0.5))
dosing_2 <- list(list(AMT=1000,RATE=NA,Time=0.5))
dosing_3 <- list(list(AMT=1000,Time=0.5))
dosing_4 <- list(list(AMT=c(1000,20),Time=c(0.5,10))) # multiple dosing


(df_12 <- model_prediction(design=design_3,DV=TRUE,dosing=dosing_1))
(df_13 <- model_prediction(design=design_3,DV=TRUE,dosing=dosing_2))
(df_14 <- model_prediction(design=design_3,DV=TRUE,dosing=dosing_3))
(df_15 <- model_prediction(design=design_3,DV=TRUE,dosing=dosing_4))


model_prediction(design=design_3,DV=TRUE,dosing=dosing_4,model_num_points = 10)
model_prediction(design=design_3,DV=TRUE,dosing=dosing_4,model_num_points = 10,model_minxt=20)

design_4 <- list(
  xt=c( 0.5,1,2,6,24,36,72,120),
  model_switch=c(1,1,1,1,2,2,2,2),
  m=2,
  groupsize=3,
  a=list(c(WT=70,AGE=50),c(AGE=45,WT=60)))

model_prediction(design=design_4,DV=TRUE,dosing=dosing_4)
model_prediction(design=design_4,DV=TRUE,dosing=dosing_4,model_num_points = 10)
model_prediction(design=design_4,DV=TRUE,dosing=dosing_4,model_num_points = 10,
                 model_minxt=10,model_maxxt=100)
model_prediction(design=design_4,DV=TRUE,dosing=dosing_4,model_num_points = 10,
                 model_minxt=c(20,20),model_maxxt=c(100,100))
model_prediction(design=design_4,DV=TRUE,dosing=dosing_4,model_num_points = c(10,10),
                 model_minxt=c(20,20),model_maxxt=c(100,100))

Normalize an objective function by the size of the FIM matrix

Description

Compute a normalized OFV based on the size of the FIM matrix. This value can then be used in efficiency calculations. This is NOT the OFV used in optimization, see ofv_fim.

Usage

ofv_criterion(
  ofv_f,
  num_parameters,
  poped.db,
  ofv_calc_type = poped.db$settings$ofv_calc_type
)

Arguments

ofv_f

An objective function
num_parameters

The number of parameters to use for normalization
poped.db

a poped database
ofv_calc_type

OFV calculation type for FIM

  • 1 = "D-optimality". Determinant of the FIM: det(FIM)

  • 2 = "A-optimality". Inverse of the sum of the expected parameter variances: 1/trace_matrix(inv(FIM))

  • 4 = "lnD-optimality". Natural logarithm of the determinant of the FIM: log(det(FIM))

  • 6 = "Ds-optimality". Ratio of the Determinant of the FIM and the Determinant of the uninteresting rows and columns of the FIM: det(FIM)/det(FIM_u)

  • 7 = Inverse of the sum of the expected parameter RSE: 1/sum(get_rse(FIM,poped.db,use_percent=FALSE))

Value

The specified criterion value.

See Also

Other FIM: LinMatrixH(), LinMatrixLH(), LinMatrixL_occ(), calc_ofv_and_fim(), ed_laplace_ofv(), ed_mftot(), efficiency(), evaluate.e.ofv.fim(), evaluate.fim(), gradf_eps(), mf3(), mf7(), mftot(), ofv_fim()

Examples

library(PopED)

############# START #################
## Create PopED database
## (warfarin model for optimization)
#####################################

## Warfarin example from software comparison in:
## Nyberg et al., "Methods and software tools for design evaluation 
##   for population pharmacokinetics-pharmacodynamics studies", 
##   Br. J. Clin. Pharm., 2014. 

## Optimization using an additive + proportional reidual error  
## to avoid sample times at very low concentrations (time 0 or very late samples).

## find the parameters that are needed to define from the structural model
ff.PK.1.comp.oral.sd.CL

## -- parameter definition function 
## -- names match parameters in function ff
sfg <- function(x,a,bpop,b,bocc){
  parameters=c(CL=bpop[1]*exp(b[1]),
               V=bpop[2]*exp(b[2]),
               KA=bpop[3]*exp(b[3]),
               Favail=bpop[4],
               DOSE=a[1])
  return(parameters) 
}

## -- Define initial design  and design space
poped.db <- create.poped.database(ff_fun=ff.PK.1.comp.oral.sd.CL,
                                  fg_fun=sfg,
                                  fError_fun=feps.add.prop,
                                  bpop=c(CL=0.15, V=8, KA=1.0, Favail=1), 
                                  notfixed_bpop=c(1,1,1,0),
                                  d=c(CL=0.07, V=0.02, KA=0.6), 
                                  sigma=c(prop=0.01,add=0.25),
                                  groupsize=32,
                                  xt=c( 0.5,1,2,6,24,36,72,120),
                                  minxt=0.01,
                                  maxxt=120,
                                  a=c(DOSE=70),
                                  mina=c(DOSE=0.01),
                                  maxa=c(DOSE=100))

############# END ###################
## Create PopED database
## (warfarin model for optimization)
#####################################


## evaluate initial design 
FIM <- evaluate.fim(poped.db) # new name for function needed
FIM
get_rse(FIM,poped.db)

ofv_criterion(ofv_fim(FIM,poped.db,ofv_calc_type=1),
              length(get_unfixed_params(poped.db)[["all"]]),
              poped.db,
              ofv_calc_type=1) # det(FIM)

ofv_criterion(ofv_fim(FIM,poped.db,ofv_calc_type=2),
              length(get_unfixed_params(poped.db)[["all"]]),
              poped.db,
              ofv_calc_type=2) 

ofv_criterion(ofv_fim(FIM,poped.db,ofv_calc_type=4),
              length(get_unfixed_params(poped.db)[["all"]]),
              poped.db,
              ofv_calc_type=4)

ofv_criterion(ofv_fim(FIM,poped.db,ofv_calc_type=6),
              length(get_unfixed_params(poped.db)[["all"]]),
              poped.db,
              ofv_calc_type=6)

ofv_criterion(ofv_fim(FIM,poped.db,ofv_calc_type=7),
              length(get_unfixed_params(poped.db)[["all"]]),
              poped.db,
              ofv_calc_type=7)

Evaluate a criterion of the Fisher Information Matrix (FIM)

Description

Compute a criterion of the FIM given the model, parameters, design and methods defined in the PopED database.

Usage

ofv_fim(
  fmf,
  poped.db,
  ofv_calc_type = poped.db$settings$ofv_calc_type,
  ds_index = poped.db$parameters$ds_index,
  use_log = TRUE,
  ...
)

Arguments

fmf

The FIM
poped.db

A poped database
ofv_calc_type

OFV calculation type for FIM

  • 1 = "D-optimality". Determinant of the FIM: det(FIM)

  • 2 = "A-optimality". Inverse of the sum of the expected parameter variances: 1/trace_matrix(inv(FIM))

  • 4 = "lnD-optimality". Natural logarithm of the determinant of the FIM: log(det(FIM))

  • 6 = "Ds-optimality". Ratio of the Determinant of the FIM and the Determinant of the uninteresting rows and columns of the FIM: det(FIM)/det(FIM_u)

  • 7 = Inverse of the sum of the expected parameter RSE: 1/sum(get_rse(FIM,poped.db,use_percent=FALSE))

ds_index

Ds_index is a vector set to 1 if a parameter is uninteresting, otherwise 0. size=(1,num unfixed parameters). First unfixed bpop, then unfixed d, then unfixed docc and last unfixed sigma. Default is the fixed effects being important, everything else not important. Used in conjunction with ofv_calc_type=6.
use_log

Should the criterion be in the log domain?
...

arguments passed to evaluate.fim and ofv_fim.

Value

The specified criterion value.

See Also

Other FIM: LinMatrixH(), LinMatrixLH(), LinMatrixL_occ(), calc_ofv_and_fim(), ed_laplace_ofv(), ed_mftot(), efficiency(), evaluate.e.ofv.fim(), evaluate.fim(), gradf_eps(), mf3(), mf7(), mftot(), ofv_criterion()

Other evaluate_FIM: calc_ofv_and_fim(), evaluate.e.ofv.fim(), evaluate.fim()

Examples

library(PopED)

############# START #################
## Create PopED database
## (warfarin model for optimization)
#####################################

## Warfarin example from software comparison in:
## Nyberg et al., "Methods and software tools for design evaluation 
##   for population pharmacokinetics-pharmacodynamics studies", 
##   Br. J. Clin. Pharm., 2014. 

## Optimization using an additive + proportional reidual error  
## to avoid sample times at very low concentrations (time 0 or very late samples).

## find the parameters that are needed to define from the structural model
ff.PK.1.comp.oral.sd.CL

## -- parameter definition function 
## -- names match parameters in function ff
sfg <- function(x,a,bpop,b,bocc){
  parameters=c(CL=bpop[1]*exp(b[1]),
               V=bpop[2]*exp(b[2]),
               KA=bpop[3]*exp(b[3]),
               Favail=bpop[4],
               DOSE=a[1])
  return(parameters) 
}

## -- Define initial design  and design space
poped.db <- create.poped.database(ff_fun=ff.PK.1.comp.oral.sd.CL,
                                  fg_fun=sfg,
                                  fError_fun=feps.add.prop,
                                  bpop=c(CL=0.15, V=8, KA=1.0, Favail=1), 
                                  notfixed_bpop=c(1,1,1,0),
                                  d=c(CL=0.07, V=0.02, KA=0.6), 
                                  sigma=c(prop=0.01,add=0.25),
                                  groupsize=32,
                                  xt=c( 0.5,1,2,6,24,36,72,120),
                                  minxt=0.01,
                                  maxxt=120,
                                  a=c(DOSE=70),
                                  mina=c(DOSE=0.01),
                                  maxa=c(DOSE=100))

############# END ###################
## Create PopED database
## (warfarin model for optimization)
#####################################


## evaluate initial design 
FIM <- evaluate.fim(poped.db) 
FIM
get_rse(FIM,poped.db)

det(FIM)
ofv_fim(FIM,poped.db,ofv_calc_type=1) # det(FIM)
ofv_fim(FIM,poped.db,ofv_calc_type=2) # 1/trace_matrix(inv(FIM))
ofv_fim(FIM,poped.db,ofv_calc_type=4) # log(det(FIM)) 
ofv_fim(FIM,poped.db,ofv_calc_type=6) # Ds with fixed effects as "important"
ofv_fim(FIM,poped.db,ofv_calc_type=6,
        ds_index=c(1,1,1,0,0,0,1,1)) # Ds with random effects as "important"
ofv_fim(FIM,poped.db,ofv_calc_type=7) # 1/sum(get_rse(FIM,poped.db,use_percent=FALSE))

Create a matrix of ones

Description

Create a matrix of ones of size (dim1 x dim2).

Usage

ones(dim1, dim2 = NULL)

Arguments

dim1

The dimension of the matrix (if square) or the number of rows.
dim2

The number of columns

Value

A matrix of ones

See Also

Other MATLAB: cell(), diag_matlab(), feval(), fileparts(), isempty(), rand(), randn(), size(), tic(), toc(), zeros()

Examples

ones(4)
ones(3,4)

Optimize a function using adaptive random search.

Description

Optimize an objective function using an adaptive random search algorithm. The function works for both discrete and continuous optimization parameters and allows for box-constraints and sets of allowed values.

Usage

optim_ARS(
  par,
  fn,
  lower = NULL,
  upper = NULL,
  allowed_values = NULL,
  loc_fac = 4,
  no_bounds_sd = par,
  iter = 400,
  iter_adapt = 50,
  adapt_scale = 1,
  max_run = 200,
  trace = TRUE,
  trace_iter = 5,
  new_par_max_it = 200,
  maximize = F,
  parallel = F,
  parallel_type = NULL,
  num_cores = NULL,
  mrgsolve_model = NULL,
  seed = round(runif(1, 0, 1e+07)),
  allow_replicates = TRUE,
  replicates_index = seq(1, length(par)),
  generator = NULL,
  ...
)

Arguments

par

A vector of initial values for the parameters to be optimized over.
fn

A function to be minimized (or maximized), with first argument the vector of parameters over which minimization is to take place. It should return a scalar result.
lower

Lower bounds on the parameters. A vector.
upper

Upper bounds on the parameters. A vector.
allowed_values

A list containing allowed values for each parameter list(par1=c(2,3,4,5,6),par2=c(5,6,7,8)). A vector containing allowed values for all parameters is also allowed c(2,3,4,5,6).
loc_fac

Locality factor for determining the standard deviation of the sampling distribution around the current position of the parameters. The initial standard deviation is normally calculated as (upper - lower)/loc_fac except in cases when there are no upper or lower limits (e.g. when upper=Inf or lower=-Inf).
no_bounds_sd

The standard deviation of the sampling distribution around the current position of the parameters when there are no upper or lower limits (e.g. when upper=Inf or lower=-Inf).
iter

The number of iterations for the algorithm to perform (this is a maximum number, it could be less).
iter_adapt

The number of iterations before adapting (shrinking) the parameter search space.
adapt_scale

The scale for adapting the size of the sampling distribution. The adaptation of the standard deviation of the sampling distribution around the current position of the parameters is done after iter_adapt iteration with no change in the best objective function. When adapting, the standard deviation of the sampling distribution is calculated as (upper - lower)/(loc_fac*ff*adapt_scale) where ff starts at 1 and increases by 1 for each adaptation.
max_run

The maximum number of iterations to run without a change in the best parameter estimates.
trace

Should the algorithm output results intermittently.
trace_iter

How many iterations between each update to the screen about the result of the search.
new_par_max_it

The algorithm randomly chooses samples based on the current best set of parameters. If when drawing these samples the new parameter set has already been tested then a new draw is performed. After new_par_max_it draws, with no new parameter sets, then the algorithm stops.
maximize

Should the function be maximized? Default is to minimize.
parallel

Should we use parallel computations?
parallel_type

Which type of parallelization should be used? Can be "snow" or "multicore". "snow" works on Linux-like systems & Windows. "multicore" works only on Linux-like systems. By default this is chosen for you depending on your operating system. See start_parallel.
num_cores

The number of cores to use in the parallelization. By default is set to the number output from parallel::detectCores(). See start_parallel.
mrgsolve_model

If the computations require a mrgsolve model and you are using the "snow" method then you need to specify the name of the model object created by mread or mcode.
seed

The random seed to use in the algorithm,
allow_replicates

Should the algorithm allow parameters to have the same value?
replicates_index

A vector, the same length as the parameters. If two values are the same in this vector then the parameters may not assume the same value in the optimization.
generator

A user-defined function that generates new parameter sets to try in the algorithm. See examples below.
...

Additional arguments passed to fn and start_parallel.

References

  1. M. Foracchia, A.C. Hooker, P. Vicini and A. Ruggeri, "PopED, a software fir optimal experimental design in population kinetics", Computer Methods and Programs in Biomedicine, 74, 2004.

  2. J. Nyberg, S. Ueckert, E.A. Stroemberg, S. Hennig, M.O. Karlsson and A.C. Hooker, "PopED: An extended, parallelized, nonlinear mixed effects models optimal design tool", Computer Methods and Programs in Biomedicine, 108, 2012.

See Also

Other Optimize: Doptim(), LEDoptim(), RS_opt(), a_line_search(), bfgsb_min(), calc_autofocus(), calc_ofv_and_grad(), mfea(), optim_LS(), poped_optim(), poped_optim_1(), poped_optim_2(), poped_optim_3(), poped_optimize()

Examples

## "wild" function , global minimum at about -15.81515
fw <- function(x) 10*sin(0.3*x)*sin(1.3*x^2) + 0.00001*x^4 + 0.2*x+80

# optimization with fewer function evaluations compared to SANN
res1 <- optim_ARS(50, fw,lower = -50, upper=100)

# often not as good performance when upper and lower bounds are poor
res2 <- optim_ARS(50, fw, lower=-Inf,upper=Inf)

# Only integer values allowed
## Not run:  
res_int <- optim_ARS(50, fw, allowed_values = seq(-50,100,by=1))

## End(Not run)

## Not run:  
  #plot of the function and solutions
  require(graphics)
  plot(fw, -50, 50, n = 1000, main = "Minimizing 'wild function'")
  points(-15.81515, fw(-15.81515), pch = 16, col = "red", cex = 1)
  points(res1$par, res1$ofv, pch = 16, col = "green", cex = 1)
  points(res2$par, res2$ofv, pch = 16, col = "blue", cex = 1)

## End(Not run) 

# optim_ARS does not work great for hard to find minima on flat surface:
# Rosenbrock Banana function
# f(x, y) = (a-x)^2 + b(y-x^2)^2
# global minimum at (x, y)=(a, a^2), where f(x, y)=0. 
# Usually a = 1 and b = 100.
## Not run:  
  fr <- function(x,a=1,b=100) {   
    x1 <- x[1]
    x2 <- x[2]
    b*(x2 - x1*x1)^2 + (a - x1)^2
  }
  
  res3 <- optim_ARS(c(-1.2,1), fr,lower = -5, upper = 5)
  
  # plot the surface
  x <- seq(-50, 50, length= 30)
  y <- x
  f <- function(x,y){apply(cbind(x,y),1,fr)}
  z <- outer(x, y, f)
  persp(x, y, z, theta = 30, phi = 30, expand = 0.5, col = "lightblue", ticktype="detailed") -> res
  points(trans3d(1, 1, 0, pmat = res), col = 2, pch = 16,cex=2)
  points(trans3d(res3$par[1], res3$par[1], res3$ofv, pmat = res), col = "green", pch = 16,cex=2)

## End(Not run)

# box constraints
flb <- function(x){
  p <- length(x) 
  sum(c(1, rep(4, p-1)) * (x - c(1, x[-p])^2)^2) 
}
## 25-dimensional box constrained
#optim(rep(3, 25), flb,lower = rep(2, 25), upper = rep(4, 25),method = "L-BFGS-B") 
res_box <- optim_ARS(rep(3, 25), flb,lower = rep(2, 25), upper = rep(4, 25)) 


## Combinatorial optimization: Traveling salesman problem
eurodistmat <- as.matrix(eurodist)

distance <- function(sq) {  # Target function
  sq2 <- embed(sq, 2)
  sum(eurodistmat[cbind(sq2[,2], sq2[,1])])
}

genseq <- function(sq) {  # Generate new candidate sequence
  idx <- seq(2, NROW(eurodistmat)-1)
  changepoints <- sample(idx, size = 2, replace = FALSE)
  tmp <- sq[changepoints[1]]
  sq[changepoints[1]] <- sq[changepoints[2]]
  sq[changepoints[2]] <- tmp
  sq
}

sq <- c(1:nrow(eurodistmat), 1)  # Initial sequence: alphabetic
res3 <- optim_ARS(sq,distance,generator=genseq) # Near optimum distance around 12842

## Not run:  
  # plot of initial sequence
  # rotate for conventional orientation
  loc <- -cmdscale(eurodist, add = TRUE)$points
  x <- loc[,1]; y <- loc[,2]
  s <- seq_len(nrow(eurodistmat))
  tspinit <- loc[sq,]
  
  plot(x, y, type = "n", asp = 1, xlab = "", ylab = "",
       main = paste("Initial sequence of traveling salesman problem\n",
                    "Distance =",distance(sq)), axes = FALSE)
  arrows(tspinit[s,1], tspinit[s,2], tspinit[s+1,1], tspinit[s+1,2],
         angle = 10, col = "green")
  text(x, y, labels(eurodist), cex = 0.8)
  
  # plot of final sequence from optim_ARS
  tspres <- loc[res3$par,]
  plot(x, y, type = "n", asp = 1, xlab = "", ylab = "",
       main = paste("optim_ARS() 'solving' traveling salesman problem\n",
                    "Distance =",distance(c(1,res3$par,1))),axes = FALSE)
  arrows(tspres[s,1], tspres[s,2], tspres[s+1,1], tspres[s+1,2],
         angle = 10, col = "red")
  text(x, y, labels(eurodist), cex = 0.8)
  
  # using optim
  set.seed(123) # chosen to get a good soln relatively quickly
  (res4 <- optim(sq, distance, genseq, method = "SANN",
                 control = list(maxit = 30000, temp = 2000, trace = TRUE,
                                REPORT = 500))) 
  
  tspres <- loc[res4$par,]
  plot(x, y, type = "n", asp = 1, xlab = "", ylab = "",
       main = paste("optim() 'solving' traveling salesman problem\n",
                    "Distance =",distance(res4$par)),axes = FALSE)
  arrows(tspres[s,1], tspres[s,2], tspres[s+1,1], tspres[s+1,2],
         angle = 10, col = "red")
  text(x, y, labels(eurodist), cex = 0.8)

## End(Not run)  

# one-dimensional function
## Not run:  
  f <- function(x)  abs(x)+cos(x)
  res5 <- optim_ARS(-20,f,lower=-20, upper=20)
  
  curve(f, -20, 20)
  abline(v = res5$par, lty = 4,col="green")

## End(Not run)  

# one-dimensional function
f <- function(x)  (x^2+x)*cos(x) # -10 < x < 10
res_max <- optim_ARS(0,f,lower=-10, upper=10,maximize=TRUE) # sometimes to local maxima

## Not run:  
  res_min <- optim_ARS(0,f,lower=-10, upper=10) # sometimes to local minima
  
  curve(f, -10, 10)
  abline(v = res_min$par, lty = 4,col="green")
  abline(v = res_max$par, lty = 4,col="red")

## End(Not run)


# two-dimensional Rastrigin function
#It has a global minimum at f(x) = f(0) = 0.
## Not run:  
  Rastrigin <- function(x1, x2){
    20 + x1^2 + x2^2 - 10*(cos(2*pi*x1) + cos(2*pi*x2))
  }
  
  
  x1 <- x2 <- seq(-5.12, 5.12, by = 0.1)
  z <- outer(x1, x2, Rastrigin)
  
  res6 <- optim_ARS(c(-4,4),function(x) Rastrigin(x[1], x[2]),lower=-5.12, upper=5.12)
  
  # color scale
  nrz <- nrow(z)
  ncz <- ncol(z)
  jet.colors <-
    colorRampPalette(c("#00007F", "blue", "#007FFF", "cyan",
                       "#7FFF7F", "yellow", "#FF7F00", "red", "#7F0000"))
  # Generate the desired number of colors from this palette
  nbcol <- 100
  color <- jet.colors(nbcol)
  # Compute the z-value at the facet centres
  zfacet <- z[-1, -1] + z[-1, -ncz] + z[-nrz, -1] + z[-nrz, -ncz]
  # Recode facet z-values into color indices
  facetcol <- cut(zfacet, nbcol)
  persp(x1, x2, z, col = color[facetcol], phi = 30, theta = 30)
  filled.contour(x1, x2, z, color.palette = jet.colors)

## End(Not run)


## Parallel computation  
## works better when each evaluation takes longer
## here we have added extra time to the computations
## just to show that it works
## Not run:  
  res7 <- optim_ARS(c(-4,4),function(x){Sys.sleep(0.01); Rastrigin(x[1], x[2])},
                    lower=-5.12, upper=5.12)
  res8 <- optim_ARS(c(-4,4),function(x){Sys.sleep(0.01); Rastrigin(x[1], x[2])},
                    lower=-5.12, upper=5.12,parallel = T)
  res9 <- optim_ARS(c(-4,4),function(x){Sys.sleep(0.01); Rastrigin(x[1], x[2])},
                    lower=-5.12, upper=5.12,parallel = T,parallel_type = "snow")

## End(Not run)

Optimize a function using a line search algorithm.

Description

optim_LS performs sequential grid search optimization of an arbitrary function with respect to each of the parameters to be optimized over. The function works for both discrete and continuous optimization parameters and allows for box-constraints (by using the upper and lower function arguments) or sets of allowed values (by using the allowed_values function argument) for all parameters, or on a parameter per parameter basis.

Usage

optim_LS(
  par,
  fn,
  lower = NULL,
  upper = NULL,
  allowed_values = NULL,
  line_length = 50,
  trace = TRUE,
  maximize = F,
  parallel = F,
  parallel_type = NULL,
  num_cores = NULL,
  mrgsolve_model = NULL,
  seed = round(runif(1, 0, 1e+07)),
  allow_replicates = TRUE,
  replicates_index = seq(1, length(par)),
  ofv_initial = NULL,
  closed_bounds = TRUE,
  ...
)

Arguments

par

A vector of initial values for the parameters to be optimized over.
fn

A function to be minimized (or maximized), with first argument the vector of parameters over which minimization is to take place. It should return a scalar result.
lower

Lower bounds on the parameters. A vector.
upper

Upper bounds on the parameters. A vector.
allowed_values

A list containing allowed values for each parameter list(par1=c(2,3,4,5,6),par2=c(5,6,7,8)). A vector containing allowed values for all parameters is also allowed c(2,3,4,5,6).
line_length

The number of different parameter values per parameter to evaluate. The values are selected as an evenly spaced grid between the upper and lower bounds.
trace

Should the algorithm output results intermittently.
maximize

Should the function be maximized? Default is to minimize.
parallel

Should we use parallel computations?
parallel_type

Which type of parallelization should be used? Can be "snow" or "multicore". "snow" works on Linux-like systems & Windows. "multicore" works only on Linux-like systems. By default this is chosen for you depending on your operating system. See start_parallel.
num_cores

The number of cores to use in the parallelization. By default is set to the number output from parallel::detectCores(). See start_parallel.
mrgsolve_model

If the computations require a mrgsolve model and you are using the "snow" method then you need to specify the name of the model object created by mread or mcode.
seed

The random seed to use in the algorithm,
allow_replicates

Should the algorithm allow parameters to have the same value?
replicates_index

A vector, the same length as the parameters. If two values are the same in this vector then the parameters may not assume the same value in the optimization.
ofv_initial

An initial objective function value (OFV). If not NULL then the initial design is not evaluated and the OFV value is assumed to be this number.
closed_bounds

Are the upper and lower limits open (boundaries not allowed) or closed (boundaries allowed) bounds?
...

Additional arguments passed to fn and start_parallel.

References

  1. M. Foracchia, A.C. Hooker, P. Vicini and A. Ruggeri, "PopED, a software fir optimal experimental design in population kinetics", Computer Methods and Programs in Biomedicine, 74, 2004.

  2. J. Nyberg, S. Ueckert, E.A. Stroemberg, S. Hennig, M.O. Karlsson and A.C. Hooker, "PopED: An extended, parallelized, nonlinear mixed effects models optimal design tool", Computer Methods and Programs in Biomedicine, 108, 2012.

See Also

Other Optimize: Doptim(), LEDoptim(), RS_opt(), a_line_search(), bfgsb_min(), calc_autofocus(), calc_ofv_and_grad(), mfea(), optim_ARS(), poped_optim(), poped_optim_1(), poped_optim_2(), poped_optim_3(), poped_optimize()

Examples

# "wild" function 
fw <- function(x) 10*sin(0.3*x)*sin(1.3*x^2) + 0.00001*x^4 + 0.2*x+80

# Global minimum of 67.47 at about -15.81515
(fw_min <- fw(-15.81515))

if (interactive()){  
  #plot of the function
  require(graphics)
  plot(fw, -50, 50, n = 10000, main = "Minimizing 'wild function'")
  
  # Known minimum
  points(-15.81515, fw_min, pch = 21, col = "red", cex = 1.5)
} 

# optimization with fewer function evaluations 
# compared to SANN: see examples in '?optim'
res1 <- optim_LS(50, fw,lower = -50, upper=50, line_length = 10000)

if (interactive()){ 
  require(graphics)
  plot(fw, -20, 0, n = 10000, main = "Minimizing 'wild function'")
  
  # Known minimum
  points(-15.81515, fw_min, pch = 21, col = "red", cex = 1.5)
  
  #plot of the optimization
  points(res1$par, res1$ofv, pch = 16, col = "green", cex = 1)
} 

# Upper and lower bounds and line_length should be considered carefully
res2 <- optim_LS(50, fw, lower=-Inf,upper=Inf,line_length = 10000)

# Only integer values allowed
res_int <- optim_LS(50, fw, allowed_values = seq(-50,50,by=1))


# Rosenbrock Banana function
# f(x, y) = (a-x)^2 + b*(y-x^2)^2
# global minimum at (x, y)=(a, a^2), where f(x, y)=0. 
# Usually a = 1 and b = 100 so x=1 and y=1
if (interactive()){ 
  fr <- function(x,a=1,b=100) {   
    x1 <- x[1]
    x2 <- x[2]
    b*(x2 - x1*x1)^2 + (a - x1)^2
  }
  
  res3 <- optim_LS(c(-1.2,1), fr,lower = -5, upper = 5, line_length = 1000)

  # plot the surface
  x <- seq(-50, 50, length= 30)
  y <- x
  f <- function(x,y){apply(cbind(x,y),1,fr)}
  z <- outer(x, y, f)
  persp(x, y, z, theta = 30, phi = 30, expand = 0.5, col = "lightblue", ticktype="detailed") -> res
  points(trans3d(1, 1, 0, pmat = res), col = 2, pch = 16,cex=2)
  points(trans3d(res3$par[1], res3$par[1], res3$ofv, pmat = res), col = "green", pch = 16,cex=1.5)
}

# box constraints
flb <- function(x){
  p <- length(x) 
  sum(c(1, rep(4, p-1)) * (x - c(1, x[-p])^2)^2) 
}

## 25-dimensional box constrained
if (interactive()){ 
  optim(rep(3, 25), flb,lower = rep(2, 25), upper = rep(4, 25),method = "L-BFGS-B") 
}
res_box <- optim_LS(rep(3, 25), flb,
                    lower = rep(2, 25), 
                    upper = rep(4, 25),
                    line_length = 1000) 

# one-dimensional function
if (interactive()){ 
  f <- function(x)  abs(x)+cos(x)
  res5 <- optim_LS(-20,f,lower=-20, upper=20, line_length = 500)
  
  curve(f, -20, 20)
  abline(v = res5$par, lty = 4,col="green")
}  

# one-dimensional function
f <- function(x)  (x^2+x)*cos(x) # -10 < x < 10
res_max <- optim_LS(0,f,lower=-10, upper=10,maximize=TRUE,line_length = 1000) 

if (interactive()){ 
  res_min <- optim_LS(0,f,lower=-10, upper=10, line_length = 1000) 
  
  curve(f, -10, 10)
  abline(v = res_min$par, lty = 4,col="green")
  abline(v = res_max$par, lty = 4,col="red")
}


# two-dimensional Rastrigin function
#It has a global minimum at f(x) = f(0) = 0.
if (interactive()){ 
  Rastrigin <- function(x1, x2){
    20 + x1^2 + x2^2 - 10*(cos(2*pi*x1) + cos(2*pi*x2))
  }
  
  
  x1 <- x2 <- seq(-5.12, 5.12, by = 0.1)
  z <- outer(x1, x2, Rastrigin)
  
  res6 <- optim_LS(c(-4,4),function(x) Rastrigin(x[1], x[2]),
                   lower=-5.12, upper=5.12, line_length = 1000)
  
  # color scale
  nrz <- nrow(z)
  ncz <- ncol(z)
  jet.colors <-
    colorRampPalette(c("#00007F", "blue", "#007FFF", "cyan",
                       "#7FFF7F", "yellow", "#FF7F00", "red", "#7F0000"))
  # Generate the desired number of colors from this palette
  nbcol <- 100
  color <- jet.colors(nbcol)
  # Compute the z-value at the facet centres
  zfacet <- z[-1, -1] + z[-1, -ncz] + z[-nrz, -1] + z[-nrz, -ncz]
  # Recode facet z-values into color indices
  facetcol <- cut(zfacet, nbcol)
  persp(x1, x2, z, col = color[facetcol], phi = 30, theta = 30)
  filled.contour(x1, x2, z, color.palette = jet.colors)
}


## Parallel computation  
## works better when each evaluation takes longer
## here we have added extra time to the computations
## just to show that it works
if (interactive()){ 
  res7 <- optim_LS(c(-4,4),function(x){Sys.sleep(0.01); Rastrigin(x[1], x[2])},
                   lower=-5.12, upper=5.12, line_length = 200)
  res8 <- optim_LS(c(-4,4),function(x){Sys.sleep(0.01); Rastrigin(x[1], x[2])},
                   lower=-5.12, upper=5.12, line_length = 200, parallel = TRUE)
  res9 <- optim_LS(c(-4,4),function(x){Sys.sleep(0.01); Rastrigin(x[1], x[2])},
                   lower=-5.12, upper=5.12, line_length = 200, parallel = TRUE, 
                   parallel_type = "snow")
}

Title Optimize the proportion of individuals in the design groups

Description

Title Optimize the proportion of individuals in the design groups

Usage

optimize_groupsize(
  poped.db,
  props = c(poped.db$design$groupsize/sum(poped.db$design$groupsize)),
  trace = 1,
  ...
)

Arguments

poped.db

A PopED database.
props

The proportions of individuals in each group (relative to the total number of individuals) to start the optimization from.
trace

Should there be tracing of the optimization? Value can be integer values. Larger numbers give more information.
...

Arguments passed to ofv_fim and optim

Value

A list of the initial objective function value, optimal proportions, the objective function value with those proportions, the optimal number of individuals in each group (with integer number of individuals), and the objective function value with that number of individuals.

Examples

# 2 design groups with either early or late samples
poped.db <- create.poped.database(ff_fun=ff.PK.1.comp.oral.sd.CL,
                                  fg_fun=function(x,a,bpop,b,bocc){
                                    parameters=c(CL=bpop[1]*exp(b[1]),
                                                 V=bpop[2]*exp(b[2]),
                                                 KA=bpop[3]*exp(b[3]),
                                                 Favail=bpop[4],
                                                 DOSE=a[1])
                                    return(parameters) 
                                  },
                                  fError_fun=feps.add.prop,
                                  bpop=c(CL=0.15, V=8, KA=1.0, Favail=1), 
                                  notfixed_bpop=c(1,1,1,0),
                                  d=c(CL=0.07, V=0.02, KA=0.6), 
                                  sigma=c(0.01,0.25),
                                  xt=list(c(1,2,3),c(4,5,20,120)),
                                  groupsize=50,
                                  minxt=0.01,
                                  maxxt=120,
                                  a=70,
                                  mina=0.01,
                                  maxa=100)


plot_model_prediction(poped.db)

evaluate_design(poped.db)


# what are the optimal proportions of 
# individuals in the two groups in the study?
(n_opt <- optimize_groupsize(poped.db))

# How many individuals in the original design are needed to achieve an
# efficiency of 1 compared to the optimized design with n=100?
optimize_n_eff(poped.db,
               ofv_ref=n_opt$opt_ofv_with_n)

Translate efficiency to number of subjects

Description

optimize HOW MANY n there should be to achieve efficiency=1 compared to a reference OFV

Usage

optimize_n_eff(poped.db, ofv_ref, norm_group_fim = NULL, ...)

Arguments

poped.db

A PopED database.
ofv_ref

A reference OFV value to compare to.
norm_group_fim

The FIM per individual in each design group. If NULL, then these are computed.
...

Arguments passed to evaluate.fim and efficiency.

Value

The number of individuals needed.

Examples

# 2 design groups with either early or late samples
poped.db <- create.poped.database(ff_fun=ff.PK.1.comp.oral.sd.CL,
                                  fg_fun=function(x,a,bpop,b,bocc){
                                    parameters=c(CL=bpop[1]*exp(b[1]),
                                                 V=bpop[2]*exp(b[2]),
                                                 KA=bpop[3]*exp(b[3]),
                                                 Favail=bpop[4],
                                                 DOSE=a[1])
                                    return(parameters) 
                                  },
                                  fError_fun=feps.add.prop,
                                  bpop=c(CL=0.15, V=8, KA=1.0, Favail=1), 
                                  notfixed_bpop=c(1,1,1,0),
                                  d=c(CL=0.07, V=0.02, KA=0.6), 
                                  sigma=c(0.01,0.25),
                                  xt=list(c(1,2,3),c(4,5,20,120)),
                                  groupsize=50,
                                  minxt=0.01,
                                  maxxt=120,
                                  a=70,
                                  mina=0.01,
                                  maxa=100)


plot_model_prediction(poped.db)

evaluate_design(poped.db)


# what are the optimal proportions of 
# individuals in the two groups in the study?
(n_opt <- optimize_groupsize(poped.db))

# How many individuals in the original design are needed to achieve an
# efficiency of 1 compared to the optimized design with n=100?
optimize_n_eff(poped.db,
               ofv_ref=n_opt$opt_ofv_with_n)

Optimize the number of subjects based on desired uncertainty of a parameter.

Description

Optimize the number of subjects, based on the current design and the desired uncertainty of a single parameter

Usage

optimize_n_rse(
  poped.db,
  bpop_idx,
  need_rse,
  use_percent = TRUE,
  allowed_values = seq(poped.db$design$m, sum(poped.db$design$groupsize) * 5, by =
    poped.db$design$m)
)

Arguments

poped.db

A PopED database.
bpop_idx

The index number of the parameter, currently only bpop parameters are allowed.
need_rse

The relative standard error (RSE) one would like to achieve (in percent, by default).
use_percent

Should the RSE be represented as a percentage (T/F)?
allowed_values

A vector of the allowed total number of subjects in the study.

Value

The total number of subjects needed and the RSE of the parameter.

Examples

# 2 design groups with either early or late samples
poped.db <- create.poped.database(ff_fun=ff.PK.1.comp.oral.sd.CL,
                                  fg_fun=function(x,a,bpop,b,bocc){
                                    parameters=c(CL=bpop[1]*exp(b[1]),
                                                 V=bpop[2]*exp(b[2]),
                                                 KA=bpop[3]*exp(b[3]),
                                                 Favail=bpop[4],
                                                 DOSE=a[1])
                                    return(parameters) 
                                  },
                                  fError_fun=feps.add.prop,
                                  bpop=c(CL=0.15, V=8, KA=1.0, Favail=1), 
                                  notfixed_bpop=c(1,1,1,0),
                                  d=c(CL=0.07, V=0.02, KA=0.6), 
                                  sigma=c(0.01,0.25),
                                  xt=list(c(1,2,3),c(4,5,20,120)),
                                  groupsize=50,
                                  minxt=0.01,
                                  maxxt=120,
                                  a=70,
                                  mina=0.01,
                                  maxa=100)

# plot of the design
plot_model_prediction(poped.db)

# the current RSE values
evaluate_design(poped.db)$rse

# number of individuals if CL should have 10% RSE
optimize_n_rse(poped.db,
                bpop_idx=1, # for CL
                need_rse=10) # the RSE you want

Parameter simulation

Description

Function generates random samples for a list of parameters

Usage

pargen(par, user_dist_pointer, sample_size, bLHS, sample_number, poped.db)

Arguments

par

A matrix describing the parameters. Each row is a parameter and the matrix has three columns:

  1. First column - Type of distribution (0-fixed, 1-normal, 2-uniform, 3-user specified, 4-lognormal, 5-Truncated normal).

  2. Second column - Mean of distribution.

  3. Third column - Variance or range of distribution.

user_dist_pointer

A text string of the name of a function that generates random samples from a user defined distribution.
sample_size

The number of random samples per parameter to generate
bLHS

Logical, indicating if Latin Hypercube Sampling should be used.
sample_number

The sample number to extract from a user distribution.
poped.db

A PopED database.

Value

A matrix of random samples of size (sample_size x number_of_parameters)

Examples

library(PopED)

############# START #################
## Create PopED database
## (warfarin example)
#####################################

## Warfarin example from software comparison in:
## Nyberg et al., "Methods and software tools for design evaluation 
##   for population pharmacokinetics-pharmacodynamics studies", 
##   Br. J. Clin. Pharm., 2014. 

## find the parameters that are needed to define from the structural model
ff.PK.1.comp.oral.sd.CL

## -- parameter definition function 
## -- names match parameters in function ff
sfg <- function(x,a,bpop,b,bocc){
  parameters=c(CL=bpop[1]*exp(b[1]),
               V=bpop[2]*exp(b[2]),
               KA=bpop[3]*exp(b[3]),
               Favail=bpop[4],
               DOSE=a[1])
  return(parameters) 
}

## -- Define model, parameters, initial design
poped.db <- create.poped.database(ff_fun=ff.PK.1.comp.oral.sd.CL,
                                  fg_fun=sfg,
                                  fError_fun=feps.prop,
                                  bpop=c(CL=0.15, V=8, KA=1.0, Favail=1), 
                                  notfixed_bpop=c(1,1,1,0),
                                  d=c(CL=0.07, V=0.02, KA=0.6), 
                                  sigma=c(prop=0.01),
                                  groupsize=32,
                                  xt=c( 0.5,1,2,6,24,36,72,120),
                                  a=c(DOSE=70))

############# END ###################
## Create PopED database
## (warfarin example)
#####################################


# Adding 40% Uncertainty to fixed effects log-normal (not Favail)
bpop_vals <- c(CL=0.15, V=8, KA=1.0, Favail=1)
bpop_vals_ed_ln <- cbind(ones(length(bpop_vals),1)*4, # log-normal distribution
                      bpop_vals,
                      ones(length(bpop_vals),1)*(bpop_vals*0.4)^2) # 40% of bpop value
bpop_vals_ed_ln["Favail",]  <- c(0,1,0)

pars.ln <- pargen(par=bpop_vals_ed_ln,
               user_dist_pointer=NULL,
               sample_size=1000,
               bLHS=1,
               sample_number=NULL,
               poped.db)


# Adding 10% Uncertainty to fixed effects normal-distribution (not Favail)
bpop_vals_ed_n <- cbind(ones(length(bpop_vals),1)*1, # log-normal distribution
                      bpop_vals,
                      ones(length(bpop_vals),1)*(bpop_vals*0.1)^2) # 10% of bpop value
bpop_vals_ed_n["Favail",]  <- c(0,1,0)

pars.n <- pargen(par=bpop_vals_ed_n,
               user_dist_pointer=NULL,
               sample_size=1000,
               bLHS=1,
               sample_number=NULL,
               poped.db)


# Adding 10% Uncertainty to fixed effects uniform-distribution (not Favail)
bpop_vals_ed_u <- cbind(ones(length(bpop_vals),1)*2, # uniform distribution
                        bpop_vals,
                        ones(length(bpop_vals),1)*(bpop_vals*0.1)) # 10% of bpop value
bpop_vals_ed_u["Favail",]  <- c(0,1,0)

pars.u <- pargen(par=bpop_vals_ed_u,
                 user_dist_pointer=NULL,
                 sample_size=1000,
                 bLHS=1,
                 sample_number=NULL,
                 poped.db)


# Adding user defined distributions
bpop_vals_ed_ud <- cbind(ones(length(bpop_vals),1)*3, # user dfined distribution
                         bpop_vals,
                         bpop_vals*0.1) # 10% of bpop value
bpop_vals_ed_ud["Favail",]  <- c(0,1,0)

# A normal distribution
my_dist <- function(...){
  par_vec <- rnorm(c(1,1,1,1),mean=bpop_vals_ed_ud[,2],sd=bpop_vals_ed_ud[,3])
}

pars.ud <- pargen(par=bpop_vals_ed_ud,
                  user_dist_pointer=my_dist,
                  sample_size=1000,
                  bLHS=1,
                  sample_number=NULL,
                  poped.db)

Plot the efficiency of windows

Description

Function plots the efficiency of windows around the sample time points. The function samples from a uniform distribution around the sample time points for each group (or each individual with deviate_by_id=TRUE, with slower calculation times) and compares the results with the design defined in poped.db. The maximal and minimal allowed values for all design variables as defined in poped.db are respected (e.g. poped.db$design_space$minxt and poped.db$design_space$maxxt).

Usage

plot_efficiency_of_windows(
  poped.db,
  xt_windows = NULL,
  xt_plus = xt_windows,
  xt_minus = xt_windows,
  iNumSimulations = 100,
  y_eff = TRUE,
  y_rse = TRUE,
  ofv_calc_type = poped.db$settings$ofv_calc_type,
  mean_line = TRUE,
  mean_color = "red",
  deviate_by_id = FALSE,
  parallel = F,
  seed = round(runif(1, 0, 1e+07)),
  ...
)

Arguments

poped.db

A poped database
xt_windows

The distance on one direction from the optimal sample times. Can be a number or a matrix of the same size as the xt matrix found in poped.db$design$xt.
xt_plus

The upper distance from the optimal sample times (xt + xt_plus). Can be a number or a matrix of the same size as the xt matrix found in poped.db$design$xt.
xt_minus

The lower distance from the optimal sample times (xt - xt_minus). Can be a number or a matrix of the same size as the xt matrix found in poped.db$design$xt.
iNumSimulations

The number of design simulations to make within the specified windows.
y_eff

Should one of the plots created have efficiency on the y-axis?
y_rse

Should created plots include the relative standard error of each parameter as a value on the y-axis?
ofv_calc_type

OFV calculation type for FIM

  • 1 = "D-optimality". Determinant of the FIM: det(FIM)

  • 2 = "A-optimality". Inverse of the sum of the expected parameter variances: 1/trace_matrix(inv(FIM))

  • 4 = "lnD-optimality". Natural logarithm of the determinant of the FIM: log(det(FIM))

  • 6 = "Ds-optimality". Ratio of the Determinant of the FIM and the Determinant of the uninteresting rows and columns of the FIM: det(FIM)/det(FIM_u)

  • 7 = Inverse of the sum of the expected parameter RSE: 1/sum(get_rse(FIM,poped.db,use_percent=FALSE))

mean_line

Should a mean value line be created?
mean_color

The color of the mean value line.
deviate_by_id

Should the computations look at deviations per individual instead of per group?
parallel

Should we use parallel computations (T/F)? Other options can be defined in this function and passed to start_parallel. See especially the options dlls and mrgsolve_model from that function if you have a model defined with compiled code or are using mrgsolve.
seed

The random seed to use.
...

Extra arguments passed to evaluate.fim

Value

A ggplot object.

See Also

Other evaluate_design: evaluate.fim(), evaluate_design(), evaluate_power(), get_rse(), model_prediction(), plot_model_prediction()

Other Simulation: model_prediction(), plot_model_prediction()

Other Graphics: plot_model_prediction()

Examples

library(PopED)

############# START #################
## Create PopED database
## (warfarin model for optimization)
#####################################

## Warfarin example from software comparison in:
## Nyberg et al., "Methods and software tools for design evaluation 
##   for population pharmacokinetics-pharmacodynamics studies", 
##   Br. J. Clin. Pharm., 2014. 

## Optimization using an additive + proportional reidual error  
## to avoid sample times at very low concentrations (time 0 or very late samples).

## find the parameters that are needed to define from the structural model
ff.PK.1.comp.oral.sd.CL

## -- parameter definition function 
## -- names match parameters in function ff
sfg <- function(x,a,bpop,b,bocc){
  parameters=c(CL=bpop[1]*exp(b[1]),
               V=bpop[2]*exp(b[2]),
               KA=bpop[3]*exp(b[3]),
               Favail=bpop[4],
               DOSE=a[1])
  return(parameters) 
}

## -- Define initial design  and design space
poped.db <- create.poped.database(ff_fun=ff.PK.1.comp.oral.sd.CL,
                                  fg_fun=sfg,
                                  fError_fun=feps.add.prop,
                                  bpop=c(CL=0.15, V=8, KA=1.0, Favail=1), 
                                  notfixed_bpop=c(1,1,1,0),
                                  d=c(CL=0.07, V=0.02, KA=0.6), 
                                  sigma=c(prop=0.01,add=0.25),
                                  groupsize=32,
                                  xt=c( 0.5,1,2,6,24,36,72,120),
                                  minxt=0.01,
                                  maxxt=120,
                                  a=c(DOSE=70),
                                  mina=c(DOSE=0.01),
                                  maxa=c(DOSE=100))

############# END ###################
## Create PopED database
## (warfarin model for optimization)
#####################################




# Examine efficiency of sampling windows at plus/minus 0.5 hours from 
# sample points in the design
plot_efficiency_of_windows(poped.db,xt_windows=0.5)


if(interactive()){  

  plot_efficiency_of_windows(poped.db,
                             xt_plus=c( 0.5,1,2,1,2,3,7,1),
                             xt_minus=c( 0.1,2,5,4,2,3,6,2))
  
  plot_efficiency_of_windows(poped.db,xt_windows=c( 0.5,1,2,1,2,3,7,1))
  
  
  plot_efficiency_of_windows(poped.db,
                             xt_plus=c( 0.5,1,2,1,2,3,7,1),
                             xt_minus=c( 0.1,2,5,4,2,3,6,2),
                             y_rse=FALSE)
  
  plot_efficiency_of_windows(poped.db,
                             xt_plus=c( 0.5,1,2,1,2,3,7,1),
                             xt_minus=c( 0.1,2,5,4,2,3,6,2),
                             y_eff=FALSE)
}

Plot model predictions

Description

Function plots model predictions for the typical value in the population, individual predictions and data predictions.

Usage

plot_model_prediction(
  poped.db,
  model_num_points = 100,
  groupsize_sim = 100,
  separate.groups = F,
  sample.times = T,
  sample.times.IPRED = F,
  sample.times.DV = F,
  PRED = T,
  IPRED = F,
  IPRED.lines = F,
  IPRED.lines.pctls = F,
  alpha.IPRED.lines = 0.1,
  alpha.IPRED = 0.3,
  sample.times.size = 4,
  DV = F,
  alpha.DV = 0.3,
  DV.lines = F,
  DV.points = F,
  alpha.DV.lines = 0.3,
  alpha.DV.points = 0.3,
  sample.times.DV.points = F,
  sample.times.DV.lines = F,
  alpha.sample.times.DV.points = 0.3,
  alpha.sample.times.DV.lines = 0.3,
  y_lab = "Model Predictions",
  facet_scales = "fixed",
  facet_label_names = T,
  model.names = NULL,
  DV.mean.sd = FALSE,
  PI = FALSE,
  PI_alpha = 0.3,
  ...
)

Arguments

poped.db

A PopED database.
model_num_points

How many extra observation rows should be created in the data frame for each group or individual per model. If used then the points are placed evenly between model_minxt and model_maxxt. This option is used by plot_model_prediction to simulate the response of the model on a finer grid then the defined design. If NULL then only the input design is used. Can be a single value or a vector the same length as the number of models.
groupsize_sim

How many individuals per group should be simulated when DV=TRUE or IPRED=TRUE to create prediction intervals?
separate.groups

Should there be separate plots for each group.
sample.times

Should sample times be shown on the plots.
sample.times.IPRED

Should sample times be shown based on the IPRED y-values.
sample.times.DV

Should sample times be shown based on the DV y-values.
PRED

Should a PRED line be drawn.
IPRED

Should we simulate individual predictions?
IPRED.lines

Should IPRED lines be drawn?
IPRED.lines.pctls

Should lines be drawn at the chosen percentiles of the IPRED values?
alpha.IPRED.lines

What should the transparency for the IPRED.lines be?
alpha.IPRED

What should the transparency of the IPRED CI?
sample.times.size

What should the size of the sample.times be?
DV

should we simulate observations?
alpha.DV

What should the transparency of the DV CI?
DV.lines

Should DV lines be drawn?
DV.points

Should DV points be drawn?
alpha.DV.lines

What should the transparency for the DV.lines be?
alpha.DV.points

What should the transparency for the DV.points be?
sample.times.DV.points

TRUE or FALSE.
sample.times.DV.lines

TRUE or FALSE.
alpha.sample.times.DV.points

What should the transparency for the sample.times.DV.points be?
alpha.sample.times.DV.lines

What should the transparency for the sample.times.DV.lines be?
y_lab

The label of the y-axis.
facet_scales

Can be "free", "fixed", "free_x" or "free_y"
facet_label_names

TRUE or FALSE
model.names

A vector of names of the response model/s (the length of the vector should be equal to the number of response models). It is Null by default.
DV.mean.sd

Plot the mean and standard deviation of simulated observations.
PI

Plot prediction intervals for the expected data given the model. Predictions are based on first-order approximations to the model variance and a normality assumption of that variance. As such these computations are more approximate than using DV=T and groupsize_sim = some large number.
PI_alpha

The transparency of the PI.
...

Additional arguments passed to the model_prediction function.

Value

A ggplot object. If you would like to further edit this plot don't forget to load the ggplot2 library using library(ggplot2).

See Also

model_prediction

Other evaluate_design: evaluate.fim(), evaluate_design(), evaluate_power(), get_rse(), model_prediction(), plot_efficiency_of_windows()

Other Simulation: model_prediction(), plot_efficiency_of_windows()

Other Graphics: plot_efficiency_of_windows()

Examples

## Warfarin example from software comparison in:
## Nyberg et al., "Methods and software tools for design evaluation 
##   for population pharmacokinetics-pharmacodynamics studies", 
##   Br. J. Clin. Pharm., 2014. 

library(PopED)

## find the parameters that are needed to define from the structural model
ff.PK.1.comp.oral.md.CL

## -- parameter definition function 
## -- names match parameters in function ff
sfg <- function(x,a,bpop,b,bocc){
  parameters=c(CL=bpop[1]*exp(b[1]),
               V=bpop[2]*exp(b[2]),
               KA=bpop[3]*exp(b[3]),
               Favail=bpop[4],
               DOSE=a[1])
    return(parameters) 
}

## -- Define initial design  and design space
poped.db <- create.poped.database(
  ff_fun=ff.PK.1.comp.oral.sd.CL,
  fg_fun=sfg,
  fError_fun=feps.prop,
  bpop=c(CL=0.15, V=8, KA=1.0, Favail=1), 
  notfixed_bpop=c(1,1,1,0),
  d=c(CL=0.07, V=0.02, KA=0.6), 
  sigma=0.01,
  groupsize=32,
  xt=c( 0.5,1,2,6,24,36,72,120),
  minxt=0,
  maxxt=120,
  a=70)

##  create plot of model without variability 
plot_model_prediction(poped.db)

##  create plot of model with variability by simulating from OMEGA and SIGMA
plot_model_prediction(poped.db,IPRED=TRUE,DV=TRUE)

##  create plot of model with variability by 
##  computing the expected variance (using an FO approximation) 
##  and then computing a prediction interval 
##  based on an assumption of normality
##  computation is faster but less accurate 
##  compared to using DV=TRUE (and groupsize_sim = 500)
plot_model_prediction(poped.db,PI=TRUE)

##-- Model: One comp first order absorption + inhibitory imax
## -- works for both mutiple and single dosing  
ff <- function(model_switch,xt,parameters,poped.db){
  with(as.list(parameters),{
    
    y=xt
    MS <- model_switch
    
    # PK model
    N = floor(xt/TAU)+1
    CONC=(DOSE*Favail/V)*(KA/(KA - CL/V)) * 
      (exp(-CL/V * (xt - (N - 1) * TAU)) * (1 - exp(-N * CL/V * TAU))/(1 - exp(-CL/V * TAU)) - 
         exp(-KA * (xt - (N - 1) * TAU)) * (1 - exp(-N * KA * TAU))/(1 - exp(-KA * TAU)))  
    
    # PD model
    EFF = E0*(1 - CONC*IMAX/(IC50 + CONC))
    
    y[MS==1] = CONC[MS==1]
    y[MS==2] = EFF[MS==2]
    
    return(list( y= y,poped.db=poped.db))
  })
}

## -- parameter definition function 
sfg <- function(x,a,bpop,b,bocc){
  parameters=c( V=bpop[1]*exp(b[1]),
                KA=bpop[2]*exp(b[2]),
                CL=bpop[3]*exp(b[3]),
                Favail=bpop[4],
                DOSE=a[1],
                TAU = a[2],
                E0=bpop[5]*exp(b[4]),
                IMAX=bpop[6],
                IC50=bpop[7])
  return( parameters ) 
}


## -- Residual Error function
feps <- function(model_switch,xt,parameters,epsi,poped.db){
  returnArgs <- ff(model_switch,xt,parameters,poped.db) 
  y <- returnArgs[[1]]
  poped.db <- returnArgs[[2]]
  
  MS <- model_switch
  
  pk.dv <- y*(1+epsi[,1])+epsi[,2]
  pd.dv <-  y*(1+epsi[,3])+epsi[,4]
  
  y[MS==1] = pk.dv[MS==1]
  y[MS==2] = pd.dv[MS==2]
  
  return(list( y= y,poped.db =poped.db )) 
}

poped.db <- 
  create.poped.database(
    ff_fun=ff,
    fError_fun=feps,
    fg_fun=sfg,
    groupsize=20,
    m=3,
    bpop=c(V=72.8,KA=0.25,CL=3.75,Favail=0.9,
           E0=1120,IMAX=0.807,IC50=0.0993),  
    notfixed_bpop=c(1,1,1,0,1,1,1),
    d=c(V=0.09,KA=0.09,CL=0.25^2,E0=0.09), 
    sigma=c(0.04,5e-6,0.09,100),
    notfixed_sigma=c(0,0,0,0),
    xt=c( 1,2,8,240,240,1,2,8,240,240),
    minxt=c(0,0,0,240,240,0,0,0,240,240),
    maxxt=c(10,10,10,248,248,10,10,10,248,248),
    discrete_xt = list(0:248),
    G_xt=c(1,2,3,4,5,1,2,3,4,5),
    bUseGrouped_xt=1,
    model_switch=c(1,1,1,1,1,2,2,2,2,2),
    a=list(c(DOSE=20,TAU=24),c(DOSE=40, TAU=24),c(DOSE=0, TAU=24)),
    maxa=c(DOSE=200,TAU=40),
    mina=c(DOSE=0,TAU=2),
    ourzero=0)

##  create plot of model and design 
plot_model_prediction(poped.db,facet_scales="free",
                      model.names = c("PK","PD"))

##  create plot of model with variability by  
##  computing the expected variance (using an FO approximation) 
##  and then computing a prediction interval 
##  based on an assumption of normality
##  computation is faster but less accurate 
##  compared to using DV=TRUE (and groupsize_sim = 500)
plot_model_prediction(poped.db,facet_scales="free",
                      model.names = c("PK","PD"),
                      PI=TRUE,
                      separate.groups = TRUE)

Run the graphical interface for PopED

Description

Run the graphical interface for PopED

Usage

poped_gui()

Optimize a design defined in a PopED database

Description

Optimize a design defined in a PopED database using the objective function described in the database (or in the arguments to this function). The function works for both discrete and continuous optimization variables.

Usage

poped_optim(
  poped.db,
  opt_xt = poped.db$settings$optsw[2],
  opt_a = poped.db$settings$optsw[4],
  opt_x = poped.db$settings$optsw[3],
  opt_samps = poped.db$settings$optsw[1],
  opt_inds = poped.db$settings$optsw[5],
  method = c("ARS", "BFGS", "LS"),
  control = list(),
  trace = TRUE,
  fim.calc.type = poped.db$settings$iFIMCalculationType,
  ofv_calc_type = poped.db$settings$ofv_calc_type,
  ds_index = poped.db$parameters$ds_index,
  approx_type = poped.db$settings$iApproximationMethod,
  d_switch = poped.db$settings$d_switch,
  ED_samp_size = poped.db$settings$ED_samp_size,
  bLHS = poped.db$settings$bLHS,
  use_laplace = poped.db$settings$iEDCalculationType,
  out_file = "",
  parallel = F,
  parallel_type = NULL,
  num_cores = NULL,
  mrgsolve_model = NULL,
  loop_methods = ifelse(length(method) > 1, TRUE, FALSE),
  iter_max = 10,
  stop_crit_eff = 1.001,
  stop_crit_diff = NULL,
  stop_crit_rel = NULL,
  ofv_fun = poped.db$settings$ofv_fun,
  maximize = T,
  allow_replicates = TRUE,
  allow_replicates_xt = TRUE,
  allow_replicates_a = TRUE,
  ...
)

Arguments

poped.db

A PopED database.
opt_xt

Should the sample times be optimized?
opt_a

Should the continuous design variables be optimized?
opt_x

Should the discrete design variables be optimized?
opt_samps

Are the number of sample times per group being optimized?
opt_inds

Are the number of individuals per group being optimized?
method

A vector of optimization methods to use in a sequential fashion. Options are c("ARS","BFGS","LS","GA"). c("ARS") is for Adaptive Random Search optim_ARS. c("LS") is for Line Search optim_LS. c("BFGS") is for Method "L-BFGS-B" from optim. c("GA") is for the genetic algorithm from ga.
control

Contains control arguments for each method specified.
trace

Should the algorithm output results intermittently.
fim.calc.type

The method used for calculating the FIM. Potential values:

  • 0 = Full FIM. No assumption that fixed and random effects are uncorrelated.

  • 1 = Reduced FIM. Assume that there is no correlation in the FIM between the fixed and random effects, and set these elements in the FIM to zero.

  • 2 = weighted models (placeholder).

  • 3 = Not currently used.

  • 4 = Reduced FIM and computing all derivatives with respect to the standard deviation of the residual unexplained variation (sqrt(SIGMA) in NONMEM). This matches what is done in PFIM, and assumes that the standard deviation of the residual unexplained variation is the estimated parameter (NOTE: NONMEM estimates the variance of the residual unexplained variation by default).

  • 5 = Full FIM parameterized with A,B,C matrices & derivative of variance.

  • 6 = Calculate one model switch at a time, good for large matrices.

  • 7 = Reduced FIM parameterized with A,B,C matrices & derivative of variance.

ofv_calc_type

OFV calculation type for FIM

  • 1 = "D-optimality". Determinant of the FIM: det(FIM)

  • 2 = "A-optimality". Inverse of the sum of the expected parameter variances: 1/trace_matrix(inv(FIM))

  • 4 = "lnD-optimality". Natural logarithm of the determinant of the FIM: log(det(FIM))

  • 6 = "Ds-optimality". Ratio of the Determinant of the FIM and the Determinant of the uninteresting rows and columns of the FIM: det(FIM)/det(FIM_u)

  • 7 = Inverse of the sum of the expected parameter RSE: 1/sum(get_rse(FIM,poped.db,use_percent=FALSE))

ds_index

Ds_index is a vector set to 1 if a parameter is uninteresting, otherwise 0. size=(1,num unfixed parameters). First unfixed bpop, then unfixed d, then unfixed docc and last unfixed sigma. Default is the fixed effects being important, everything else not important. Used in conjunction with ofv_calc_type=6.
approx_type

Approximation method for model, 0=FO, 1=FOCE, 2=FOCEI, 3=FOI.
d_switch

  • ******START OF CRITERION SPECIFICATION OPTIONS**********

D-family design (1) or ED-family design (0) (with or without parameter uncertainty)
ED_samp_size

Sample size for E-family sampling
bLHS

How to sample from distributions in E-family calculations. 0=Random Sampling, 1=LatinHyperCube –
use_laplace

Should the Laplace method be used in calculating the expectation of the OFV?
out_file

Save output from the optimization to a file.
parallel

Should we use parallel computations?
parallel_type

Which type of parallelization should be used? Can be "snow" or "multicore". "snow" works on Linux-like systems & Windows. "multicore" works only on Linux-like systems. By default this is chosen for you depending on your operating system. See start_parallel.
num_cores

The number of cores to use in the parallelization. By default is set to the number output from parallel::detectCores(). See start_parallel.
mrgsolve_model

If the computations require a mrgsolve model and you are using the "snow" method then you need to specify the name of the model object created by mread or mcode.
loop_methods

Should the optimization methods be looped for iter_max iterations, or until the efficiency of the design after the current series (compared to the start of the series) is less than, or equal to, stop_crit_eff?
iter_max

If line search is used then the algorithm tests if line search (always run at the end of the optimization iteration) changes the design in any way. If not, the algorithm stops. If yes, then a new iteration is run unless iter_max iterations have already been run.
stop_crit_eff

If loop_methods==TRUE, the looping will stop if the efficiency of the design after the current series (compared to the start of the series) is less than, or equal to, stop_crit_eff (if maximize==FALSE then 1/stop_crit_eff is the cut off and the efficiency must be greater than or equal to this value to stop the looping).
stop_crit_diff

If loop_methods==TRUE, the looping will stop if the difference in criterion value of the design after the current series (compared to the start of the series) is less than, or equal to, stop_crit_diff (if maximize==FALSE then -stop_crit_diff is the cut off and the difference in criterion value must be greater than or equal to this value to stop the looping).
stop_crit_rel

If loop_methods==TRUE, the looping will stop if the relative difference in criterion value of the design after the current series (compared to the start of the series) is less than, or equal to, stop_crit_rel (if maximize==FALSE then -stop_crit_rel is the cut off and the relative difference in criterion value must be greater than or equal to this value to stop the looping).
ofv_fun

User defined function used to compute the objective function. The function must have a poped database object as its first argument and have "..." in its argument list. Can be referenced as a function or as a file name where the function defined in the file has the same name as the file. e.g. "cost.txt" has a function named "cost" in it.
maximize

Should the objective function be maximized or minimized?
allow_replicates

Should the algorithm allow optimized design components to have the same value? If FALSE then all discrete optimizations will not allow replicates within variable types (equivalent to allow_replicates_xt=FALSE and allow_replicates_a=FALSE).
allow_replicates_xt

Should the algorithm allow optimized xt design components to have the same value? If FALSE then all discrete optimizations will not allow replicates.
allow_replicates_a

Should the algorithm allow optimized a design components to have the same value? If FALSE then all discrete optimizations will not allow replicates.
...

arguments passed to other functions.

Details

This function takes information from the PopED database supplied as an argument. The PopED database supplies information about the the model, parameters, design and methods to use. Some of the arguments coming from the PopED database can be overwritten; if they are supplied then they are used instead of the arguments from the PopED database.

If more than one optimization method is specified then the methods are run in series. If loop_methods=TRUE then the series of optimization methods will be run for iter_max iterations, or until the efficiency of the design after the current series (compared to the start of the series) is less than stop_crit_eff.

References

  1. M. Foracchia, A.C. Hooker, P. Vicini and A. Ruggeri, "PopED, a software fir optimal experimental design in population kinetics", Computer Methods and Programs in Biomedicine, 74, 2004.

  2. J. Nyberg, S. Ueckert, E.A. Stroemberg, S. Hennig, M.O. Karlsson and A.C. Hooker, "PopED: An extended, parallelized, nonlinear mixed effects models optimal design tool", Computer Methods and Programs in Biomedicine, 108, 2012.

See Also

Other Optimize: Doptim(), LEDoptim(), RS_opt(), a_line_search(), bfgsb_min(), calc_autofocus(), calc_ofv_and_grad(), mfea(), optim_ARS(), optim_LS(), poped_optim_1(), poped_optim_2(), poped_optim_3(), poped_optimize()

Examples

library(PopED)

############# START #################
## Create PopED database
## (warfarin model for optimization)
#####################################

## Warfarin example from software comparison in:
## Nyberg et al., "Methods and software tools for design evaluation 
##   for population pharmacokinetics-pharmacodynamics studies", 
##   Br. J. Clin. Pharm., 2014. 

## Optimization using an additive + proportional reidual error  
## to avoid sample times at very low concentrations (time 0 or very late samples).

## find the parameters that are needed to define from the structural model
ff.PK.1.comp.oral.sd.CL

## -- parameter definition function 
## -- names match parameters in function ff
sfg <- function(x,a,bpop,b,bocc){
  parameters=c(CL=bpop[1]*exp(b[1]),
               V=bpop[2]*exp(b[2]),
               KA=bpop[3]*exp(b[3]),
               Favail=bpop[4],
               DOSE=a[1])
  return(parameters) 
}

## -- Define initial design  and design space
poped.db <- create.poped.database(ff_fun=ff.PK.1.comp.oral.sd.CL,
                                  fg_fun=sfg,
                                  fError_fun=feps.add.prop,
                                  bpop=c(CL=0.15, V=8, KA=1.0, Favail=1), 
                                  notfixed_bpop=c(1,1,1,0),
                                  d=c(CL=0.07, V=0.02, KA=0.6), 
                                  sigma=c(prop=0.01,add=0.25),
                                  groupsize=32,
                                  xt=c( 0.5,1,2,6,24,36,72,120),
                                  minxt=0.01,
                                  maxxt=120,
                                  a=c(DOSE=70),
                                  mina=c(DOSE=0.01),
                                  maxa=c(DOSE=100))

############# END ###################
## Create PopED database
## (warfarin model for optimization)
#####################################

##############
# D-family Optimization
##############

# below are a number of ways to optimize the problem


# ARS+BFGS+LS optimization of dose
# optimization with just a few iterations
# only to check that things are working
out_1 <- poped_optim(poped.db,opt_a =TRUE,
                      control = list(ARS=list(iter=2),
                                     BFGS=list(maxit=2),
                                     LS=list(line_length=2)),
                      iter_max = 1)


# cost function
# PRED at 120 hours
crit_fcn <- function(poped.db,...){
  pred_df <- model_prediction(poped.db)
  return(pred_df[pred_df$Time==120,"PRED"])
}

# maximize cost function
out_2 <- poped_optim(poped.db,opt_a =TRUE,
                     ofv_fun=crit_fcn,
                     control = list(ARS=list(iter=2),
                                    BFGS=list(maxit=2),
                                    LS=list(line_length=2)),
                     iter_max = 2)

# minimize the cost function
out_3 <- poped_optim(poped.db,opt_a =TRUE,
                     ofv_fun=crit_fcn,
                     control = list(ARS=list(iter=2),
                                    BFGS=list(maxit=2),
                                    LS=list(line_length=2)),
                     iter_max = 2,
                     maximize = FALSE,
                     evaluate_fim = FALSE)


## Not run: 
  
  # RS+BFGS+LS optimization of sample times 
  # (longer run time than above but more likely to reach a maximum)
  output <- poped_optim(poped.db,opt_xt=T,parallel = TRUE)
  
  get_rse(output$FIM,output$poped.db)
  plot_model_prediction(output$poped.db)
  
  # optimization with only integer times allowed
  poped.db.2 <- poped.db
  poped.db.2$design_space$xt_space <- matrix(list(seq(1,120)),1,8)
  output_2 <- poped_optim(poped.db.2,opt_xt=T,parallel = TRUE)

  get_rse(output_2$FIM,output_2$poped.db)
  plot_model_prediction(output_2$poped.db)
  
  # Examine efficiency of sampling windows
  plot_efficiency_of_windows(output_2$poped.db,xt_windows=0.5)
  plot_efficiency_of_windows(output_2$poped.db,xt_windows=1)
  
  # Adaptive Random Search (ARS, just a few samples here)
  rs.output <- poped_optim(poped.db,opt_xt=T,method = "ARS",
                           control = list(ARS=list(iter=5)))
  
  get_rse(rs.output$FIM,rs.output$poped.db)
  
  # line search, DOSE and sample time optimization
  ls.output <- poped_optim(poped.db,opt_xt=T,opt_a=T,method = "LS",
                           control = list(LS=list(line_length=5)))
  
  # Adaptive random search, 
  # DOSE and sample time optimization
  ars.output <- poped_optim(poped.db,opt_xt=T,opt_a=T,method = "ARS",
                           control = list(ARS=list(iter=5)))
  
  # BFGS gradient search from the stats::optim() function, 
  # DOSE and sample time optimization
  bfgs.output <- poped_optim(poped.db,opt_xt=T,opt_a=T,method = "BFGS",
                            control = list(BFGS=list(maxit=5)))
  
  
  # genetic algorithm from the GA::ga() function, 
  # DOSE and sample time optimization
  ga.output <- poped_optim(poped.db,opt_xt=T,opt_a=F,method = "GA",parallel=T)
  
  # cost function with GA
  # maximize
  out_2 <- poped_optim(poped.db,opt_a =TRUE,
                       ofv_fun=crit_fcn,
                       parallel = T,
                       method=c("GA"))
  
  # cost function with GA
  # minimize
  out_2 <- poped_optim(poped.db,opt_a =TRUE,
                       ofv_fun=crit_fcn,
                       parallel = T,
                       method=c("GA"),
                       iter_max = 1,
                       maximize = F,
                       evaluate_fim = F)
  
  # optimize distribution of individuals in 3 groups
  poped_db_2 <- create.poped.database(
    ff_fun=ff.PK.1.comp.oral.sd.CL,
    fg_fun=sfg,
    fError_fun=feps.add.prop,
    bpop=c(CL=0.15, V=8, KA=1.0, Favail=1), 
    notfixed_bpop=c(1,1,1,0),
    d=c(CL=0.07, V=0.02, KA=0.6), 
    sigma=c(prop=0.01,add=0.25),
    groupsize=32,
    m=3,
    xt=list(c( 0.5,1,2,6,8),c(36,72,120),
            c(10,12,14,16,18,20,22,24)),
    minxt=0.01,
    maxxt=120,
    a=c(DOSE=70),
    mina=c(DOSE=0.01),
    maxa=c(DOSE=100))
  
  opt_xt_inds <- 
    poped_optim(poped_db_2,
                opt_a =TRUE,
                opt_inds = TRUE,
                control = list(ARS=list(iter=2),
                               BFGS=list(maxit=2),
                               LS=list(line_length=2)),
                iter_max = 1)
  
  
  
  ##############
  # E-family Optimization
  ##############
  
  # Adding 10% log-normal Uncertainty to fixed effects (not Favail)
  bpop_vals <- c(CL=0.15, V=8, KA=1.0, Favail=1)
  bpop_vals_ed_ln <- cbind(ones(length(bpop_vals),1)*4, # log-normal distribution
                           bpop_vals,
                           ones(length(bpop_vals),1)*(bpop_vals*0.1)^2) # 10% of bpop value
  bpop_vals_ed_ln["Favail",]  <- c(0,1,0)
  bpop_vals_ed_ln
  
  ## -- Define initial design  and design space
  poped.db <- create.poped.database(
    ff_fun=ff.PK.1.comp.oral.sd.CL,
    fg_fun=sfg,
    fError_fun=feps.add.prop,
    bpop=bpop_vals_ed_ln, 
    notfixed_bpop=c(1,1,1,0),
    d=c(CL=0.07, V=0.02, KA=0.6), 
    sigma=c(0.01,0.25),
    groupsize=32,
    xt=c( 0.5,1,2,6,24,36,72,120),
    minxt=0,
    maxxt=120,
    a=70,
    mina=0,
    maxa=100)
  
  
  # E_ln(D) optimization using Random search (just a few samples here)
  output <- poped_optim(poped.db,opt_xt=TRUE,opt_a=TRUE,d_switch=0,
                        method = c("ARS","LS"),
                        control = list(ARS=list(iter=2),
                                       LS=list(line_length=2)),
                        iter_max = 1)
  get_rse(output$FIM,output$poped.db)
  
  # ED with laplace approximation, 
  # optimization using Random search (just a few iterations here)
  ars.output <- poped_optim(poped.db,opt_xt=T,opt_a=T,method = "ARS",
                            d_switch=0,use_laplace=TRUE,#laplace.fim=TRUE,
                            parallel=T,
                            control = list(ARS=list(iter=5)))
  

## End(Not run)

Retired optimization module for PopED

Description

This function is an older version of poped_optim. Please use poped_optim unless you have a specific reason to use this function instead.

Usage

poped_optimize(
  poped.db,
  ni = NULL,
  xt = NULL,
  model_switch = NULL,
  x = NULL,
  a = NULL,
  bpop = NULL,
  d = NULL,
  maxxt = NULL,
  minxt = NULL,
  maxa = NULL,
  mina = NULL,
  fmf = 0,
  dmf = 0,
  trflag = TRUE,
  opt_xt = poped.db$settings$optsw[2],
  opt_a = poped.db$settings$optsw[4],
  opt_x = poped.db$settings$optsw[3],
  opt_samps = poped.db$settings$optsw[1],
  opt_inds = poped.db$settings$optsw[5],
  cfaxt = poped.db$settings$cfaxt,
  cfaa = poped.db$settings$cfaa,
  rsit = poped.db$settings$rsit,
  rsit_output = poped.db$settings$rsit_output,
  fim.calc.type = poped.db$settings$iFIMCalculationType,
  ofv_calc_type = poped.db$settings$ofv_calc_type,
  approx_type = poped.db$settings$iApproximationMethod,
  bUseExchangeAlgorithm = poped.db$settings$bUseExchangeAlgorithm,
  iter = 1,
  d_switch = poped.db$settings$d_switch,
  ED_samp_size = poped.db$settings$ED_samp_size,
  bLHS = poped.db$settings$bLHS,
  use_laplace = poped.db$settings$iEDCalculationType,
  ...
)

Arguments

poped.db

A PopED database.
ni

A vector of the number of samples in each group.
xt

A matrix of sample times. Each row is a vector of sample times for a group.
model_switch

A matrix that is the same size as xt, specifying which model each sample belongs to.
x

A matrix for the discrete design variables. Each row is a group.
a

A matrix of covariates. Each row is a group.
bpop

Matrix defining the fixed effects, per row (row number = parameter_number) we should have:

  • column 1 the type of the distribution for E-family designs (0 = Fixed, 1 = Normal, 2 = Uniform, 3 = User Defined Distribution, 4 = lognormal and 5 = truncated normal)

  • column 2 defines the mean.

  • column 3 defines the variance of the distribution (or length of uniform distribution).

Can also just supply the parameter values as a vector c() if no uncertainty around the parameter value is to be used. The parameter order of 'bpop' is defined in the 'fg_fun' or 'fg_file'. If you use named arguments in 'bpop' then the order of this vector can be rearranged to match the 'fg_fun' or 'fg_file'. See 'reorder_parameter_vectors'.
d

Matrix defining the diagonals of the IIV (same logic as for the fixed effects matrix bpop to define uncertainty). One can also just supply the parameter values as a c(). The parameter order of 'd' is defined in the 'fg_fun' or 'fg_file'. If you use named arguments in 'd' then the order of this vector can be rearranged to match the 'fg_fun' or 'fg_file'. See 'reorder_parameter_vectors'.
maxxt

Matrix or single value defining the maximum value for each xt sample. If a single value is supplied then all xt values are given the same maximum value.
minxt

Matrix or single value defining the minimum value for each xt sample. If a single value is supplied then all xt values are given the same minimum value
maxa

Vector defining the max value for each covariate. If a single value is supplied then all a values are given the same max value
mina

Vector defining the min value for each covariate. If a single value is supplied then all a values are given the same max value
fmf

The initial value of the FIM. If set to zero then it is computed.
dmf

The initial OFV. If set to zero then it is computed.
trflag

Should the optimization be output to the screen and to a file?
opt_xt

Should the sample times be optimized?
opt_a

Should the continuous design variables be optimized?
opt_x

Should the discrete design variables be optimized?
opt_samps

Are the number of sample times per group being optimized?
opt_inds

Are the number of individuals per group being optimized?
cfaxt

First step factor for sample times
cfaa

Stochastic Gradient search first step factor for covariates
rsit

Number of Random search iterations
rsit_output

Number of iterations in random search between screen output
fim.calc.type

The method used for calculating the FIM. Potential values:

  • 0 = Full FIM. No assumption that fixed and random effects are uncorrelated.

  • 1 = Reduced FIM. Assume that there is no correlation in the FIM between the fixed and random effects, and set these elements in the FIM to zero.

  • 2 = weighted models (placeholder).

  • 3 = Not currently used.

  • 4 = Reduced FIM and computing all derivatives with respect to the standard deviation of the residual unexplained variation (sqrt(SIGMA) in NONMEM). This matches what is done in PFIM, and assumes that the standard deviation of the residual unexplained variation is the estimated parameter (NOTE: NONMEM estimates the variance of the residual unexplained variation by default).

  • 5 = Full FIM parameterized with A,B,C matrices & derivative of variance.

  • 6 = Calculate one model switch at a time, good for large matrices.

  • 7 = Reduced FIM parameterized with A,B,C matrices & derivative of variance.

ofv_calc_type

OFV calculation type for FIM

  • 1 = "D-optimality". Determinant of the FIM: det(FIM)

  • 2 = "A-optimality". Inverse of the sum of the expected parameter variances: 1/trace_matrix(inv(FIM))

  • 4 = "lnD-optimality". Natural logarithm of the determinant of the FIM: log(det(FIM))

  • 6 = "Ds-optimality". Ratio of the Determinant of the FIM and the Determinant of the uninteresting rows and columns of the FIM: det(FIM)/det(FIM_u)

  • 7 = Inverse of the sum of the expected parameter RSE: 1/sum(get_rse(FIM,poped.db,use_percent=FALSE))

approx_type

Approximation method for model, 0=FO, 1=FOCE, 2=FOCEI, 3=FOI.
bUseExchangeAlgorithm

Use Exchange algorithm (1=TRUE, 0=FALSE)
iter

The number of iterations entered into the blockheader_2 function.
d_switch

  • ******START OF CRITERION SPECIFICATION OPTIONS**********

D-family design (1) or ED-family design (0) (with or without parameter uncertainty)
ED_samp_size

Sample size for E-family sampling
bLHS

How to sample from distributions in E-family calculations. 0=Random Sampling, 1=LatinHyperCube –
use_laplace

Should the Laplace method be used in calculating the expectation of the OFV?
...

arguments passed to other functions. See Doptim.

Details

This function optimized the objective function. The function works for both discrete and continuous optimization variables. This function takes information from the PopED database supplied as an argument. The PopED database supplies information about the the model, parameters, design and methods to use. Some of the arguments coming from the PopED database can be overwritten; if they are supplied then they are used instead of the arguments from the PopED database.

References

  1. M. Foracchia, A.C. Hooker, P. Vicini and A. Ruggeri, "PopED, a software fir optimal experimental design in population kinetics", Computer Methods and Programs in Biomedicine, 74, 2004.

  2. J. Nyberg, S. Ueckert, E.A. Stroemberg, S. Hennig, M.O. Karlsson and A.C. Hooker, "PopED: An extended, parallelized, nonlinear mixed effects models optimal design tool", Computer Methods and Programs in Biomedicine, 108, 2012.

See Also

Other Optimize: Doptim(), LEDoptim(), RS_opt(), a_line_search(), bfgsb_min(), calc_autofocus(), calc_ofv_and_grad(), mfea(), optim_ARS(), optim_LS(), poped_optim(), poped_optim_1(), poped_optim_2(), poped_optim_3()

Examples

library(PopED)

############# START #################
## Create PopED database
## (warfarin model for optimization)
#####################################

## Warfarin example from software comparison in:
## Nyberg et al., "Methods and software tools for design evaluation 
##   for population pharmacokinetics-pharmacodynamics studies", 
##   Br. J. Clin. Pharm., 2014. 

## Optimization using an additive + proportional reidual error  
## to avoid sample times at very low concentrations (time 0 or very late samples).

## find the parameters that are needed to define from the structural model
ff.PK.1.comp.oral.sd.CL

## -- parameter definition function 
## -- names match parameters in function ff
sfg <- function(x,a,bpop,b,bocc){
  parameters=c(CL=bpop[1]*exp(b[1]),
               V=bpop[2]*exp(b[2]),
               KA=bpop[3]*exp(b[3]),
               Favail=bpop[4],
               DOSE=a[1])
  return(parameters) 
}

## -- Define initial design  and design space
poped.db <- create.poped.database(ff_fun=ff.PK.1.comp.oral.sd.CL,
                                  fg_fun=sfg,
                                  fError_fun=feps.add.prop,
                                  bpop=c(CL=0.15, V=8, KA=1.0, Favail=1), 
                                  notfixed_bpop=c(1,1,1,0),
                                  d=c(CL=0.07, V=0.02, KA=0.6), 
                                  sigma=c(prop=0.01,add=0.25),
                                  groupsize=32,
                                  xt=c( 0.5,1,2,6,24,36,72,120),
                                  minxt=0.01,
                                  maxxt=120,
                                  a=c(DOSE=70),
                                  mina=c(DOSE=0.01),
                                  maxa=c(DOSE=100))

############# END ###################
## Create PopED database
## (warfarin model for optimization)
#####################################


##############
# D-family Optimization
##############

# below are a number of ways to optimize the problem

# RS+SG+LS optimization of DOSE and sample times
# optimization with just a few iterations
# only to check that things are working
out_1 <- poped_optimize(poped.db,opt_a=TRUE,opt_xt=TRUE,
                         rsit=2,sgit=2,ls_step_size=2, 
                         iter_max=1,out_file = "")

## Not run: 
  
  # RS+SG+LS optimization of sample times 
  # (longer run time than above but more likely to reach a maximum)
  output <- poped_optimize(poped.db,opt_xt=T)
  get_rse(output$fmf,output$poped.db)
  plot_model_prediction(output$poped.db)
  
  # MFEA optimization with only integer times allowed
  mfea.output <- poped_optimize(poped.db,opt_xt=1,
                                bUseExchangeAlgorithm=1,
                                EAStepSize=1)
  get_rse(mfea.output$fmf,mfea.output$poped.db)
  plot_model_prediction(mfea.output$poped.db)
  
  # Examine efficiency of sampling windows
  plot_efficiency_of_windows(mfea.output$poped.db,xt_windows=0.5)
  plot_efficiency_of_windows(mfea.output$poped.db,xt_windows=1)
  
  # Random search (just a few samples here)
  rs.output <- poped_optimize(poped.db,opt_xt=1,opt_a=1,rsit=20,
                              bUseRandomSearch= 1,
                              bUseStochasticGradient = 0,
                              bUseBFGSMinimizer = 0,
                              bUseLineSearch = 0)
  get_rse(rs.output$fmf,rs.output$poped.db)
  
  # line search, DOSE and sample time optimization
  ls.output <- poped_optimize(poped.db,opt_xt=1,opt_a=1,
                              bUseRandomSearch= 0,
                              bUseStochasticGradient = 0,
                              bUseBFGSMinimizer = 0,
                              bUseLineSearch = 1,
                              ls_step_size=10)
  
  # Stochastic gradient search, DOSE and sample time optimization
  sg.output <- poped_optimize(poped.db,opt_xt=1,opt_a=1, 
                              bUseRandomSearch= 0,
                              bUseStochasticGradient = 1,
                              bUseBFGSMinimizer = 0,
                              bUseLineSearch = 0,
                              sgit=20)
  
  # BFGS search, DOSE and sample time optimization
  bfgs.output <- poped_optimize(poped.db,opt_xt=1,opt_a=1,
                                bUseRandomSearch= 0,
                                bUseStochasticGradient = 0,
                                bUseBFGSMinimizer = 1,
                                bUseLineSearch = 0)
  
  ##############
  # E-family Optimization
  ##############
  
  # Adding 10% log-normal Uncertainty to fixed effects (not Favail)
  bpop_vals <- c(CL=0.15, V=8, KA=1.0, Favail=1)
  bpop_vals_ed_ln <- cbind(ones(length(bpop_vals),1)*4, # log-normal distribution
                           bpop_vals,
                           ones(length(bpop_vals),1)*(bpop_vals*0.1)^2) # 10% of bpop value
  bpop_vals_ed_ln["Favail",]  <- c(0,1,0)
  bpop_vals_ed_ln
  
  ## -- Define initial design  and design space
  poped.db <- create.poped.database(
    ff_fun=ff.PK.1.comp.oral.sd.CL,
    fg_fun=sfg,
    fError_fun=feps.add.prop,
    bpop=bpop_vals_ed_ln, 
    notfixed_bpop=c(1,1,1,0),
    d=c(CL=0.07, V=0.02, KA=0.6), 
    sigma=c(0.01,0.25),
    groupsize=32,
    xt=c( 0.5,1,2,6,24,36,72,120),
    minxt=0,
    maxxt=120,
    a=70,
    mina=0,
    maxa=100)
  
  # ED optimization using Random search (just a few samples here)
  output <- poped_optimize(poped.db,opt_xt=1,opt_a=1,rsit=10,d_switch=0)
  get_rse(output$fmf,output$poped.db)
  
  # ED with laplace approximation, 
  # optimization using Random search (just a few samples here)
  output <- poped_optimize(poped.db,opt_xt=1,opt_a=1,rsit=10,
                           d_switch=0,use_laplace=TRUE,laplace.fim=TRUE)
  get_rse(output$fmf,output$poped.db)
  
  

## End(Not run)

Optimize the objective function using an adaptive random search algorithm for D-family and E-family designs.

Description

Optimize the objective function using an adaptive random search algorithm. Optimization can be performed for both D-family and E-family designs. The function works for both discrete and continuous optimization variables. This function takes information from the PopED database supplied as an argument. The PopED database supplies information about the the model, parameters, design and methods to use. Some of the arguments coming from the PopED database can be overwritten; by default these arguments are NULL in the function, if they are supplied then they are used instead of the arguments from the PopED database.

Usage

RS_opt(
  poped.db,
  ni = NULL,
  xt = NULL,
  model_switch = NULL,
  x = NULL,
  a = NULL,
  bpopdescr = NULL,
  ddescr = NULL,
  maxxt = NULL,
  minxt = NULL,
  maxa = NULL,
  mina = NULL,
  fmf = 0,
  dmf = 0,
  trflag = TRUE,
  opt_xt = poped.db$settings$optsw[2],
  opt_a = poped.db$settings$optsw[4],
  opt_x = poped.db$settings$optsw[3],
  cfaxt = poped.db$settings$cfaxt,
  cfaa = poped.db$settings$cfaa,
  rsit = poped.db$settings$rsit,
  rsit_output = poped.db$settings$rsit_output,
  fim.calc.type = poped.db$settings$iFIMCalculationType,
  approx_type = poped.db$settings$iApproximationMethod,
  iter = NULL,
  d_switch = poped.db$settings$d_switch,
  use_laplace = poped.db$settings$iEDCalculationType,
  laplace.fim = FALSE,
  header_flag = TRUE,
  footer_flag = TRUE,
  out_file = NULL,
  compute_inv = TRUE,
  ...
)

Arguments

poped.db

A PopED database.
ni

A vector of the number of samples in each group.
xt

A matrix of sample times. Each row is a vector of sample times for a group.
model_switch

A matrix that is the same size as xt, specifying which model each sample belongs to.
x

A matrix for the discrete design variables. Each row is a group.
a

A matrix of covariates. Each row is a group.
bpopdescr

Matrix defining the fixed effects, per row (row number = parameter_number) we should have:

  • column 1 the type of the distribution for E-family designs (0 = Fixed, 1 = Normal, 2 = Uniform, 3 = User Defined Distribution, 4 = lognormal and 5 = truncated normal)

  • column 2 defines the mean.

  • column 3 defines the variance of the distribution (or length of uniform distribution).

ddescr

Matrix defining the diagonals of the IIV (same logic as for the bpopdescr).
maxxt

Matrix or single value defining the maximum value for each xt sample. If a single value is supplied then all xt values are given the same maximum value.
minxt

Matrix or single value defining the minimum value for each xt sample. If a single value is supplied then all xt values are given the same minimum value
maxa

Vector defining the max value for each covariate. If a single value is supplied then all a values are given the same max value
mina

Vector defining the min value for each covariate. If a single value is supplied then all a values are given the same max value
fmf

The initial value of the FIM. If set to zero then it is computed.
dmf

The initial OFV. If set to zero then it is computed.
trflag

Should the optimization be output to the screen and to a file?
opt_xt

Should the sample times be optimized?
opt_a

Should the continuous design variables be optimized?
opt_x

Should the discrete design variables be optimized?
cfaxt

First step factor for sample times
cfaa

Stochastic Gradient search first step factor for covariates
rsit

Number of Random search iterations
rsit_output

Number of iterations in random search between screen output
fim.calc.type

The method used for calculating the FIM. Potential values:

  • 0 = Full FIM. No assumption that fixed and random effects are uncorrelated.

  • 1 = Reduced FIM. Assume that there is no correlation in the FIM between the fixed and random effects, and set these elements in the FIM to zero.

  • 2 = weighted models (placeholder).

  • 3 = Not currently used.

  • 4 = Reduced FIM and computing all derivatives with respect to the standard deviation of the residual unexplained variation (sqrt(SIGMA) in NONMEM). This matches what is done in PFIM, and assumes that the standard deviation of the residual unexplained variation is the estimated parameter (NOTE: NONMEM estimates the variance of the residual unexplained variation by default).

  • 5 = Full FIM parameterized with A,B,C matrices & derivative of variance.

  • 6 = Calculate one model switch at a time, good for large matrices.

  • 7 = Reduced FIM parameterized with A,B,C matrices & derivative of variance.

approx_type

Approximation method for model, 0=FO, 1=FOCE, 2=FOCEI, 3=FOI.
iter

The number of iterations entered into the blockheader_2 function.
d_switch

  • ******START OF CRITERION SPECIFICATION OPTIONS**********

D-family design (1) or ED-family design (0) (with or without parameter uncertainty)
use_laplace

Should the Laplace method be used in calculating the expectation of the OFV?
laplace.fim

Should an E(FIM) be calculated when computing the Laplace approximated E(OFV). Typically the FIM does not need to be computed and, if desired, this calculation is done using the standard MC integration technique, so can be slow.
header_flag

Should the header text be printed out?
footer_flag

Should the footer text be printed out?
out_file

Which file should the output be directed to? A string, a file handle using file or "" will output to the screen.
compute_inv

should the inverse of the FIM be used to compute expected RSE values? Often not needed except for diagnostic purposes.
...

arguments passed to evaluate.fim and ofv_fim.

References

  1. M. Foracchia, A.C. Hooker, P. Vicini and A. Ruggeri, "PopED, a software fir optimal experimental design in population kinetics", Computer Methods and Programs in Biomedicine, 74, 2004.

  2. J. Nyberg, S. Ueckert, E.A. Stroemberg, S. Hennig, M.O. Karlsson and A.C. Hooker, "PopED: An extended, parallelized, nonlinear mixed effects models optimal design tool", Computer Methods and Programs in Biomedicine, 108, 2012.

See Also

Other Optimize: Doptim(), LEDoptim(), a_line_search(), bfgsb_min(), calc_autofocus(), calc_ofv_and_grad(), mfea(), optim_ARS(), optim_LS(), poped_optim(), poped_optim_1(), poped_optim_2(), poped_optim_3(), poped_optimize()

Examples

library(PopED)

############# START #################
## Create PopED database
## (warfarin model for optimization
##  with parameter uncertainty)
#####################################

## Warfarin example from software comparison in:
## Nyberg et al., "Methods and software tools for design evaluation 
##   for population pharmacokinetics-pharmacodynamics studies", 
##   Br. J. Clin. Pharm., 2014. 

## Optimization using an additive + proportional reidual error
## to avoid sample times at very low concentrations (time 0 or very late samoples).

## find the parameters that are needed to define from the structural model
ff.PK.1.comp.oral.sd.CL

## -- parameter definition function 
## -- names match parameters in function ff
sfg <- function(x,a,bpop,b,bocc){
  parameters=c(CL=bpop[1]*exp(b[1]),
               V=bpop[2]*exp(b[2]),
               KA=bpop[3]*exp(b[3]),
               Favail=bpop[4],
               DOSE=a[1])
  return(parameters) 
}

# Adding 10% log-normal Uncertainty to fixed effects (not Favail)
bpop_vals <- c(CL=0.15, V=8, KA=1.0, Favail=1)
bpop_vals_ed_ln <- cbind(ones(length(bpop_vals),1)*4, # log-normal distribution
                         bpop_vals,
                         ones(length(bpop_vals),1)*(bpop_vals*0.1)^2) # 10% of bpop value
bpop_vals_ed_ln["Favail",]  <- c(0,1,0)
bpop_vals_ed_ln

## -- Define initial design  and design space
poped.db <- create.poped.database(ff_fun=ff.PK.1.comp.oral.sd.CL,
                                  fg_fun=sfg,
                                  fError_fun=feps.add.prop,
                                  bpop=bpop_vals_ed_ln, 
                                  notfixed_bpop=c(1,1,1,0),
                                  d=c(CL=0.07, V=0.02, KA=0.6), 
                                  sigma=c(0.01,0.25),
                                  groupsize=32,
                                  xt=c( 0.5,1,2,6,24,36,72,120),
                                  minxt=0,
                                  maxxt=120,
                                  a=70,
                                  mina=0,
                                  maxa=100)

############# END ###################
## Create PopED database
## (warfarin model for optimization
##  with parameter uncertainty)
#####################################


# Just a few iterations, optimize on DOSE and sample times using the full FIM
out_1 <- RS_opt(poped.db,opt_xt=1,opt_a=1,rsit=3,fim.calc.type=0, out_file = "")

## Not run: 
  
  RS_opt(poped.db)
  
  RS_opt(poped.db,opt_xt=TRUE,rsit=100,compute_inv=F)
  RS_opt(poped.db,opt_xt=TRUE,rsit=20,d_switch=0)
  RS_opt(poped.db,opt_xt=TRUE,rsit=10,d_switch=0,use_laplace=T)
  RS_opt(poped.db,opt_xt=TRUE,rsit=10,d_switch=0,use_laplace=T,laplace.fim=T)
  
  ## Different headers and footers of output
  RS_opt(poped.db,opt_xt=TRUE,rsit=10,out_file="foo.txt")
  output <- RS_opt(poped.db,opt_xt=TRUE,rsit=100,trflag=FALSE)
  RS_opt(poped.db,opt_xt=TRUE,rsit=10,out_file="")
  RS_opt(poped.db,opt_xt=TRUE,rsit=10,header_flag=FALSE)
  RS_opt(poped.db,opt_xt=TRUE,rsit=10,footer_flag=FALSE)
  RS_opt(poped.db,opt_xt=TRUE,rsit=10,header_flag=FALSE,footer_flag=FALSE)
  RS_opt(poped.db,opt_xt=TRUE,rsit=10,header_flag=FALSE,footer_flag=FALSE,out_file="foo.txt")
  RS_opt(poped.db,opt_xt=TRUE,rsit=10,header_flag=FALSE,footer_flag=FALSE,out_file="") 


## End(Not run)

Predict shrinkage of empirical Bayes estimates (EBEs) in a population model

Description

Predict shrinkage of empirical Bayes estimates (EBEs) in a population model

Usage

shrinkage(poped.db, use_mc = FALSE, num_sim_ids = 1000, use_purrr = FALSE)

Arguments

poped.db

A PopED database
use_mc

Should the calculation be based on monte-carlo simulations. If not then then a first order approximation is used
num_sim_ids

If use_mc=TRUE, how many individuals should be simulated to make the computations.
use_purrr

If use_mc=TRUE then should the method use the package purrr in calculations? This may speed up computations (potentially).

Value

The shrinkage computed in variance units, standard deviation units and the relative standard errors of the EBEs.

References

  1. Combes, F. P., Retout, S., Frey, N., & Mentre, F. (2013). Prediction of shrinkage of individual parameters using the Bayesian information matrix in non-linear mixed effect models with evaluation in pharmacokinetics. Pharmaceutical Research, 30(9), 2355-67. doi:10.1007/s11095-013-1079-3.

  2. Hennig, S., Nyberg, J., Fanta, S., Backman, J. T., Hoppu, K., Hooker, A. C., & Karlsson, M. O. (2012). Application of the optimal design approach to improve a pretransplant drug dose finding design for ciclosporin. Journal of Clinical Pharmacology, 52(3), 347-360. doi:10.1177/0091270010397731.

Examples

library(PopED)

############# START #################
## Create PopED database
## (warfarin example)
#####################################

## Warfarin example from software comparison in:
## Nyberg et al., "Methods and software tools for design evaluation 
##   for population pharmacokinetics-pharmacodynamics studies", 
##   Br. J. Clin. Pharm., 2014. 

## find the parameters that are needed to define from the structural model
ff.PK.1.comp.oral.sd.CL

## -- parameter definition function 
## -- names match parameters in function ff
sfg <- function(x,a,bpop,b,bocc){
  parameters=c(CL=bpop[1]*exp(b[1]),
               V=bpop[2]*exp(b[2]),
               KA=bpop[3]*exp(b[3]),
               Favail=bpop[4],
               DOSE=a[1])
  return(parameters) 
}

## -- Define model, parameters, initial design
poped.db <- create.poped.database(ff_fun=ff.PK.1.comp.oral.sd.CL,
                                  fg_fun=sfg,
                                  fError_fun=feps.prop,
                                  bpop=c(CL=0.15, V=8, KA=1.0, Favail=1), 
                                  notfixed_bpop=c(1,1,1,0),
                                  d=c(CL=0.07, V=0.02, KA=0.6), 
                                  sigma=c(prop=0.01),
                                  groupsize=32,
                                  xt=c( 0.5,1,2,6,24,36,72,120),
                                  a=c(DOSE=70))

############# END ###################
## Create PopED database
## (warfarin example)
#####################################

shrinkage(poped.db)

Function written to match MATLAB's size function

Description

Function written to match MATLAB's size function

Usage

size(obj, dimension.index = NULL)

Arguments

obj

An object you want to know the various dimensions of. Typically a matrix.
dimension.index

Which dimension you are interested in.

Value

The dimensions of the object or specific dimension you are interested in.

See Also

Other MATLAB: cell(), diag_matlab(), feval(), fileparts(), isempty(), ones(), rand(), randn(), tic(), toc(), zeros()

Examples

size(c(2,3,4,5,6))

size(10)

size(zeros(4,7))

Start parallel computational processes

Description

This tool chooses the type of parallelization process to use based on the computer OS being used. For windows the default is "snow" and for Linux-like systems the default is "multicore"

Usage

start_parallel(
  parallel = TRUE,
  num_cores = NULL,
  parallel_type = NULL,
  seed = NULL,
  dlls = NULL,
  mrgsolve_model = NULL,
  ...
)

Arguments

parallel

Should the parallel functionality start up?
num_cores

How many cores to use. Default is parallel::detectCores()-1 . See detectCores for more information.
parallel_type

Which type of parallelization should be used? Can be "snow" or "multicore". "snow" works on Linux-like systems & Windows. "multicore" works only on Linux-like systems. By default this is chosen for you depending on your operating system.
seed

The random seed to use.
dlls

If the computations require compiled code (DLL's) and you are using the "snow" method then you need to specify the name of the DLL's without the extension as a text vector c("this_file","that_file").
mrgsolve_model

If the computations require a mrgsolve model and you are using the "snow" method" then you need to specify the name of the model object created by mread or mcode
...

Arguments passed to makeCluster

Value

An atomic vector (TRUE or FALSE) with two attributes: "type" and "cores".

Display a summary of output from poped_optim

Description

Display a summary of output from poped_optim

Usage

## S3 method for class 'poped_optim'
summary(object, ...)

Arguments

object

An object returned from poped_optim to summarize.
...

Additional arguments. Passed to blockfinal.

Examples

library(PopED)

############# START #################
## Create PopED database
## (warfarin model for optimization)
#####################################

## Warfarin example from software comparison in:
## Nyberg et al., "Methods and software tools for design evaluation 
##   for population pharmacokinetics-pharmacodynamics studies", 
##   Br. J. Clin. Pharm., 2014. 

## Optimization using an additive + proportional reidual error  
## to avoid sample times at very low concentrations (time 0 or very late samples).

## find the parameters that are needed to define from the structural model
ff.PK.1.comp.oral.sd.CL

## -- parameter definition function 
## -- names match parameters in function ff
sfg <- function(x,a,bpop,b,bocc){
  parameters=c(CL=bpop[1]*exp(b[1]),
               V=bpop[2]*exp(b[2]),
               KA=bpop[3]*exp(b[3]),
               Favail=bpop[4],
               DOSE=a[1])
  return(parameters) 
}

## -- Define initial design  and design space
poped.db <- create.poped.database(ff_fun=ff.PK.1.comp.oral.sd.CL,
                                  fg_fun=sfg,
                                  fError_fun=feps.add.prop,
                                  bpop=c(CL=0.15, V=8, KA=1.0, Favail=1), 
                                  notfixed_bpop=c(1,1,1,0),
                                  d=c(CL=0.07, V=0.02, KA=0.6), 
                                  sigma=c(prop=0.01,add=0.25),
                                  groupsize=32,
                                  xt=c( 0.5,1,2,6,24,36,72,120),
                                  minxt=0.01,
                                  maxxt=120,
                                  a=c(DOSE=70),
                                  mina=c(DOSE=0.01),
                                  maxa=c(DOSE=100))

############# END ###################
## Create PopED database
## (warfarin model for optimization)
#####################################

##############
# D-family Optimization
##############


# ARS+BFGS+LS optimization of dose
# optimization with just a few iterations
# only to check that things are working
out_1 <- poped_optim(poped.db,opt_a =TRUE,
                      control = list(ARS=list(iter=2),
                                     BFGS=list(maxit=2),
                                     LS=list(line_length=2)),
                      iter_max = 1)


summary(out_1)

Timer function (as in MATLAB)

Description

Function to start a timer. Stop with toc().

Usage

tic(gcFirst = FALSE, name = ".poped_savedTime")

Arguments

gcFirst

Perform garbage collection?
name

The saved name of the time object.

Note

This is a modified version of the same function in the matlab R-package.

See Also

Other MATLAB: cell(), diag_matlab(), feval(), fileparts(), isempty(), ones(), rand(), randn(), size(), toc(), zeros()

Examples

tic()
toc()

tic(name="foo")
toc()
tic()
toc()
toc()
tic()
toc(name="foo")

Timer function (as in MATLAB)

Description

Function to stop a timer. Start with tic().

Usage

toc(echo = TRUE, name = ".poped_savedTime")

Arguments

echo

Print time to screen?
name

The saved name of the time object.

Note

This is a modified version of the same function in the matlab R-package.

See Also

Other MATLAB: cell(), diag_matlab(), feval(), fileparts(), isempty(), ones(), rand(), randn(), size(), tic(), zeros()

Examples

tic()
toc()

tic(name="foo")
toc()
tic()
toc()
toc()
tic()
toc(name="foo")

Create a matrix of zeros.

Description

Create a matrix of zeros of size (dim1 x dim2).

Usage

zeros(dim1, dim2 = NULL)

Arguments

dim1

The dimension of the matrix (if square) or the number of rows.
dim2

The number of columns

Value

A matrix of zeros.

See Also

Other MATLAB: cell(), diag_matlab(), feval(), fileparts(), isempty(), ones(), rand(), randn(), size(), tic(), toc()

Examples

zeros(3)
zeros(0,3)
zeros(4,7)
zeros(1,4)