Package 'psychonetrics'

Title: Structural Equation Modeling and Confirmatory Network Analysis
Description: Multi-group (dynamical) structural equation models in combination with confirmatory network models from cross-sectional, time-series and panel data <doi:10.31234/osf.io/8ha93>. Allows for confirmatory testing and fit as well as exploratory model search.
Authors: Sacha Epskamp
Maintainer: Sacha Epskamp <[email protected]>
License: GPL-2
Version: 0.13
Built: 2024-10-25 06:52:45 UTC
Source: CRAN

Help Index


Structural Equation Modeling and Confirmatory Network Analysis

Description

Multi-group (dynamical) structural equation models in combination with confirmatory network models from cross-sectional, time-series and panel data <doi:10.31234/osf.io/8ha93>. Allows for confirmatory testing and fit as well as exploratory model search.

Details

The DESCRIPTION file:

Package: psychonetrics
Type: Package
Title: Structural Equation Modeling and Confirmatory Network Analysis
Version: 0.13
Author: Sacha Epskamp
Maintainer: Sacha Epskamp <[email protected]>
Description: Multi-group (dynamical) structural equation models in combination with confirmatory network models from cross-sectional, time-series and panel data <doi:10.31234/osf.io/8ha93>. Allows for confirmatory testing and fit as well as exploratory model search.
License: GPL-2
LinkingTo: Rcpp (>= 0.11.3), RcppArmadillo, pbv, roptim
Depends: R (>= 4.3.0)
Imports: methods, qgraph, numDeriv, dplyr, abind, Matrix (>= 1.6-5), lavaan, corpcor, glasso, mgcv, optimx, VCA, pbapply, parallel, magrittr, IsingSampler, tidyr, psych, GA, combinat, rlang
Suggests: psychTools, semPlot, graphicalVAR, metaSEM, mvtnorm, ggplot2
ByteCompile: true
URL: http://psychonetrics.org/
BugReports: https://github.com/SachaEpskamp/psychonetrics/issues
StagedInstall: true
NeedsCompilation: yes
Packaged: 2024-06-20 17:09:07 UTC; Sacha
Repository: CRAN
Date/Publication: 2024-06-20 18:00:02 UTC

Index of help topics:

CIplot                  Plot Analytic Confidence Intervals
Ising                   Ising model
Jonas                   Jonas dataset
MIs                     Print modification indices
StarWars                Star Wars dataset
addMIs                  Model updating functions
aggregate_bootstraps    Aggregate Bootstrapped Models
bifactor                Bi-factor models
bootstrap               Bootstrap a psychonetrics model
changedata              Change the data of a psychonetrics object
checkJacobian           Diagnostic functions
compare                 Model comparison
covML                   Maximum likelihood covariance estimate
dlvm1                   Lag-1 dynamic latent variable model family of
                        psychonetrics models for panel data
duplicationMatrix       Model matrices used in derivatives
emergencystart          Reset starting values to simple defaults
esa                     Ergodic Subspace Analysis
factorscores            Compute factor scores
fit                     Print fit indices
fixpar                  Parameters modification
fixstart                Attempt to Fix Starting Values
generate                Generate data from a fitted psychonetrics
                        object
getVCOV                 Obtain the asymptotic covariance matrix
getmatrix               Extract an estimated matrix
groupequal              Group equality constrains
latentgrowth            Latnet growth curve model
logbook                 Retrieve the psychonetrics logbook
lvm                     Continuous latent variable family of
                        psychonetrics models
meta_varcov             Variance-covariance and GGM meta analysis
ml_lvm                  Multi-level latent variable model family
ml_tsdlvm1              Multi-level Lag-1 dynamic latent variable model
                        family of psychonetrics models for time-series
                        data
modelsearch             Stepwise model search
parameters              Print parameter estimates
parequal                Set equality constrains across parameters
partialprune            Partial pruning of multi-group models
prune                   Stepdown model search by pruning
                        non-significant parameters.
psychonetrics-class     Class '"psychonetrics"'
psychonetrics-package   Structural Equation Modeling and Confirmatory
                        Network Analysis
psychonetrics_bootstrap-class
                        Class '"psychonetrics_bootstrap"'
psychonetrics_log-class
                        Class '"psychonetrics"'
runmodel                Run a psychonetrics model
setestimator            Convenience functions
setverbose              Should messages of computation progress be
                        printed?
simplestructure         Generate factor loadings matrix with simple
                        structure
stepup                  Stepup model search along modification indices
transmod                Transform between model types
tsdlvm1                 Lag-1 dynamic latent variable model family of
                        psychonetrics models for time-series data
unionmodel              Unify models across groups
var1                    Lag-1 vector autoregression family of
                        psychonetrics models
varcov                  Variance-covariance family of psychonetrics
                        models

This package can be used to perform Structural Equation Modeling and confirmatory network modeling. Current implemented families of models are (1) the variance–covariance matrix (varcov), (2) the latent variable model (lvm), (3) the lag-1 vector autoregression model (var1), and (4) the dynamical lag-1 latent variable model for panel data (dlvm1) and for time-series data (tsdlvm1).

Author(s)

Sacha Epskamp

Maintainer: Sacha Epskamp <[email protected]>

References

More information: psychonetrics.org


Aggregate Bootstrapped Models

Description

Aggregates bootstrap results into a psychonetrics_bootstrap object

Usage

aggregate_bootstraps(sample, bootstraps, remove_problematic = TRUE)

Arguments

sample

The original psychonetrics object (not bootstrapped)

bootstraps

A list of bootstrapped psychonetrics objects (i.e., using bootstrap = TRUE)

remove_problematic

Remove bootstraps that did not converge (sum of absolute gradient > 1)

Details

After running this function, the helper functions parameters, fit, and CIplot can be used to investigate bootstrap results.

Value

An object of the class psychonetrics_bootstrap

Author(s)

Sacha Epskamp


Bi-factor models

Description

Wrapper to lvm to specify a bi-factor model.

Usage

bifactor(data, lambda, latents, bifactor = "g", ...)

Arguments

data

The data as used by lvm

lambda

The factor loadings matrix *without* the bifactor, as used by by lvm

latents

A vector of names of the latent variables, as used by lvm

bifactor

Name of the bifactor

...

Arguments sent to lvm

Value

An object of the class psychonetrics (psychonetrics-class)

Author(s)

Sacha Epskamp


Bootstrap a psychonetrics model

Description

This function will bootstrap the data (once) and return a new unevaluated psychonetrics object. It requres storedata = TRUE to be used when forming a model.

Usage

bootstrap(x, replacement = TRUE, proportion = 1, verbose = TRUE, storedata = FALSE, 
          baseline_saturated = TRUE)

Arguments

x

A psychonetrics model.

replacement

Logical, should new samples be drawn with replacement?

proportion

Proportion of sample to be drawn. Set to lower than $1$ for subsampling.

verbose

Logical, should messages be printed?

storedata

Logical, should the bootstrapped data also be stored?

baseline_saturated

Logical, should the baseline and saturated models be included?

Value

An object of the class psychonetrics (psychonetrics-class)

Author(s)

Sacha Epskamp


Change the data of a psychonetrics object

Description

This function can be used to change the data in a psychonetrics object.

Usage

changedata(x, data, covs, nobs, means, groups, missing = "listwise")

Arguments

x

A psychonetrics model.

data

A data frame encoding the data used in the analysis. Can be missing if covs and nobs are supplied.

covs

A sample variance–covariance matrix, or a list/array of such matrices for multiple groups. IMPORTANT NOTE: psychonetrics expects the maximum likelihood (ML) covariance matrix, which is NOT obtained from cov directly. Manually rescale the result of cov with (nobs - 1)/nobs to obtain the ML covariance matrix.

nobs

The number of observations used in covs and means, or a vector of such numbers of observations for multiple groups.

means

A vector of sample means, or a list/matrix containing such vectors for multiple groups.

groups

An optional string indicating the name of the group variable in data.

missing

How should missingness be handled in computing the sample covariances and number of observations when data is used. Can be "listwise" for listwise deletion, or "pairwise" for pairwise deletion.

Value

An object of the class psychonetrics (psychonetrics-class)

Author(s)

Sacha Epskamp


Plot Analytic Confidence Intervals

Description

Function to plot analytic confidence intervals (CI) of matrix elements estimated in psychonetrics.

Usage

CIplot(x, matrices, alpha_ci = 0.05, alpha_color = c(0.05,
                   0.01, 0.001, 1e-04), labels, labels2, labelstart,
                   print = TRUE, major_break = 0.2, minor_break = 0.1,
                   split0, prop0, prop0_cex = 1, prop0_alpha = 0.95,
                   prop0_minAlpha = 0.25)

Arguments

x

A psychonetrics model.

matrices

Vector of strings indicating the matrices to plot CIs for

alpha_ci

The alpha level used for the CIs

alpha_color

A vector of alphas used for coloring the CIs

labels

The labels for the variables associated with the rows of a matrix.

labels2

The labels for the variables associated with the columns of a matrix. Defaults to the value of labels for square matrices.

labelstart

The value to determine if labels are printed to the right or to the left of the CI

print

Logical, should the plots also be printed? Only works when one matrix is used in 'matrices'

major_break

Numeric indicating the step size between major breaks

minor_break

Numeric indicating the step size between minor breaks

split0

Logical only used for results of aggregate_bootstraps. When set to TRUE, the displayed intervals are based on occasions when the parameter was not estimated to be zero, and an extra box is added indicating the number of times a parameter is estimated to be zero. Defaults to TRUE when model selection is used and FALSE otherwise.

prop0

Logical only used for results of aggregate_bootstraps, should boxes indicating the proportion of times parameters were estimated to be zero be added to the plot? Defaults to the value of split0.

prop0_cex

Only used for results of aggregate_bootstraps. Size of the boxes indicating number of times a parameter was set to zero.

prop0_alpha

Only used for results of aggregate_bootstraps. Transparency of the boxes indicating number of times a parameter was set to zero.

prop0_minAlpha

Only used for results of aggregate_bootstraps. Minimal transparency of the *lines* of plotted intervals as the proportion of times an edge was not included goes to 0.

Value

A single ggplot2 object, or a list of ggplot2 objects for each matrix requested.

Author(s)

Sacha Epskamp

Examples

### Example from ?ggm ###
# Load bfi data from psych package:
library("psychTools")
data(bfi)

# Also load dplyr for the pipe operator:
library("dplyr")

# Let's take the agreeableness items, and gender:
ConsData <- bfi %>% 
  select(A1:A5, gender) %>% 
  na.omit # Let's remove missingness (otherwise use Estimator = "FIML)

# Define variables:
vars <- names(ConsData)[1:5]

# Let's fit an empty GGM:
mod0 <- ggm(ConsData, vars = vars)

# Run the model:
mod0 <- mod0 %>% runmodel

# Labels:
labels <- c(
  "indifferent to the feelings of others",
  "inquire about others' well-being",
  "comfort others",
  "love children",
  "make people feel at ease")

# Plot the CIs:
CIplot(mod0,  "omega", labels = labels, labelstart = 0.2)

### Example from ?gvar ###
library("dplyr")
library("graphicalVAR")

beta <- matrix(c(
  0,0.5,
  0.5,0
),2,2,byrow=TRUE)
kappa <- diag(2)
simData <- graphicalVARsim(50, beta, kappa)

# Form model:
model <- gvar(simData)

# Evaluate model:
model <- model %>% runmodel

# Plot the CIs:
CIplot(model,  "beta")

Model comparison

Description

This function will print a table comparing multiple models on chi-square, AIC and BIC.

Usage

compare(...)

## S3 method for class 'psychonetrics_compare'
print(x, ...)

Arguments

...

Any number of psychonetrics models. Can be named to change the rownames of the output.

x

Output of the compare function.

Value

A data frame with chi-square values, degrees of freedoms, RMSEAs, AICs, and BICs.

Author(s)

Sacha Epskamp


Maximum likelihood covariance estimate

Description

These functions complement the base R cov function by simplifying obtaining maximum likelihood (ML) covariance estimates (denominator n) instead of unbiased (UB) covariance estimates (denominator n-1). The function covML can be used to obtain ML estimates, the function covUBtoML transforms from UB to ML estimates, and the function covMLtoUB transforms from UB to ML estimates.

Usage

covML(x, ...)
covUBtoML(x, n, ...)
covMLtoUB(x, n, ...)

Arguments

x

A dataset

n

The sample size

...

Arguments sent to the cov function.

Author(s)

Sacha Epskamp <[email protected]>

Examples

data("StarWars")
Y <- StarWars[,1:10]

# Unbiased estimate:
UB <- cov(Y)

# ML Estimate:
ML <- covML(Y)

# Check:
all(abs(UB - covMLtoUB(ML, nrow(Y))) < sqrt(.Machine$double.eps))
all(abs(ML - covUBtoML(UB, nrow(Y))) < sqrt(.Machine$double.eps))

Diagnostic functions

Description

The 'checkJacobian' function can be used to check if the analytic gradient / Jacobian is aligned with the numerically approximated gradient / Jacobian, and the 'checkFisher' function can be used to check if the analytic Hessian is aligned with the numerically approximated Hessian.

Usage

checkJacobian(x, f = "default", jac = "default", transpose = FALSE, 
          plot = TRUE, perturbStart = FALSE, method = "Richardson")

checkFisher(x, f = "default", fis = "default", transpose = FALSE, 
          plot = TRUE,  perturbStart = FALSE)

Arguments

x

A 'psychonetrics' object

f

A custom fit function or the psychonetrics default fit function (default).

jac

A custom Jacobian function or the psychonetrics default Jacobian function (default).

fis

A custom Fischer information function or the psychonetrics default Fischer information function (default).

transpose

Should the numeric Jacobian be transposed?

plot

Should a diagnostic plot be produced?

perturbStart

Should start values be perturbed (only used in development)

method

Numeric derivative method (default: Richardson)

Author(s)

Sacha Epskamp


Lag-1 dynamic latent variable model family of psychonetrics models for panel data

Description

This is the family of models that models a dynamic factor model on panel data. There are four covariance structures that can be modeled in different ways: within_latent, between_latent for the within-person and between-person latent (contemporaneous) models respectively, and within_residual, between_residual for the within-person and between-person residual models respectively. The panelgvar wrapper function sets the lambda to an identity matrix, all residual variances to zero, and models within-person and between-person latent (contemporaneous) models as GGMs. The panelvar wrapper does the same but models contemporaneous relations as a variance-covariance matrix. Finally, the panel_lvgvar wrapper automatically models all latent networks as GGMs.

Usage

dlvm1(data, vars, lambda, within_latent = c("cov", "chol",
                   "prec", "ggm"), within_residual = c("cov", "chol",
                   "prec", "ggm"), between_latent = c("cov", "chol",
                   "prec", "ggm"), between_residual = c("cov", "chol",
                   "prec", "ggm"), beta = "full", omega_zeta_within =
                   "full", delta_zeta_within = "diag", kappa_zeta_within
                   = "full", sigma_zeta_within = "full",
                   lowertri_zeta_within = "full", omega_epsilon_within =
                   "zero", delta_epsilon_within = "diag",
                   kappa_epsilon_within = "diag", sigma_epsilon_within =
                   "diag", lowertri_epsilon_within = "diag",
                   omega_zeta_between = "full", delta_zeta_between =
                   "diag", kappa_zeta_between = "full",
                   sigma_zeta_between = "full", lowertri_zeta_between =
                   "full", omega_epsilon_between = "zero",
                   delta_epsilon_between = "diag", kappa_epsilon_between
                   = "diag", sigma_epsilon_between = "diag",
                   lowertri_epsilon_between = "diag", nu, mu_eta,
                   identify = TRUE, identification = c("loadings",
                   "variance"), latents, groups, covs, means, nobs, start
                   = "version2", covtype = c("choose", "ML", "UB"),
                   missing = "listwise", equal = "none",
                   baseline_saturated = TRUE, estimator = "ML",
                   optimizer, storedata = FALSE, verbose = FALSE,
                   sampleStats, baseline =
                   c("stationary_random_intercept", "stationary",
                   "independence", "none"), bootstrap = FALSE, boot_sub,
                   boot_resample)

panelgvar(data, vars, within_latent = c("ggm","chol","cov","prec"), 
          between_latent = c("ggm","chol","cov","prec"), ...)

panelvar(data, vars, within_latent = c("cov","chol","prec","ggm"), 
          between_latent = c("cov","chol","prec","ggm"), ...)

panel_lvgvar(...)

Arguments

data

A data frame encoding the data used in the analysis. Can be missing if covs and nobs are supplied.

vars

Required argument. Different from in other psychonetrics models, this must be a *matrix* with each row indicating a variable and each column indicating a measurement. The matrix must be filled with names of the variables in the dataset corresponding to variable i at wave j. NAs can be used to indicate missing waves. The rownames of this matrix will be used as variable names.

lambda

Required argument. A model matrix encoding the factor loading structure. Each row indicates an indicator and each column a latent. A 0 encodes a fixed to zero element, a 1 encoding a free to estimate element, and higher integers encoding equality constrains. For multiple groups, this argument can be a list or array with each element/slice encoding such a matrix.

within_latent

The type of within-person latent contemporaneous model to be used.

within_residual

The type of within-person residual model to be used.

between_latent

The type of between-person latent model to be used.

between_residual

The type of between-person residual model to be used.

beta

A model matrix encoding the temporal relationships (transpose of temporal network). A 0 encodes a fixed to zero element, a 1 encoding a free to estimate element, and higher integers encoding equality constrains. For multiple groups, this argument can be a list or array with each element/slice encoding such a matrix. Can also be "full" for a full temporal network or "zero" for an empty temporal network.

omega_zeta_within

Only used when within_latent = "ggm". Can be "full", "zero", or a typical model matrix with 0s indicating parameters constrained to zero, 1s indicating free parameters, and higher integers indicating equality constrains. For multiple groups, this argument can be a list or array with each element/slice encoding such a matrix.

delta_zeta_within

Only used when within_latent = "ggm". Can be "diag", "zero" (not recommended), or a typical model matrix with 0s indicating parameters constrained to zero, 1s indicating free parameters, and higher integers indicating equality constrains. For multiple groups, this argument can be a list or array with each element/slice encoding such a matrix.

kappa_zeta_within

Only used when within_latent = "prec". Can be "full", "diag", or a typical model matrix with 0s indicating parameters constrained to zero, 1s indicating free parameters, and higher integers indicating equality constrains. For multiple groups, this argument can be a list or array with each element/slice encoding such a matrix.

sigma_zeta_within

Only used when within_latent = "cov". Can be "full", "diag", or a typical model matrix with 0s indicating parameters constrained to zero, 1s indicating free parameters, and higher integers indicating equality constrains. For multiple groups, this argument can be a list or array with each element/slice encoding such a matrix.

lowertri_zeta_within

Only used when within_latent = "chol". Can be "full", "diag", or a typical model matrix with 0s indicating parameters constrained to zero, 1s indicating free parameters, and higher integers indicating equality constrains. For multiple groups, this argument can be a list or array with each element/slice encoding such a matrix.

omega_epsilon_within

Only used when within_residual = "ggm". Can be "full", "zero", or a typical model matrix with 0s indicating parameters constrained to zero, 1s indicating free parameters, and higher integers indicating equality constrains. For multiple groups, this argument can be a list or array with each element/slice encoding such a matrix.

delta_epsilon_within

Only used when within_residual = "ggm". Can be "diag", "zero" (not recommended), or a typical model matrix with 0s indicating parameters constrained to zero, 1s indicating free parameters, and higher integers indicating equality constrains. For multiple groups, this argument can be a list or array with each element/slice encoding such a matrix.

kappa_epsilon_within

Only used when within_residual = "prec". Can be "full", "diag", or a typical model matrix with 0s indicating parameters constrained to zero, 1s indicating free parameters, and higher integers indicating equality constrains. For multiple groups, this argument can be a list or array with each element/slice encoding such a matrix.

sigma_epsilon_within

Only used when within_residual = "cov". Can be "full", "diag", or a typical model matrix with 0s indicating parameters constrained to zero, 1s indicating free parameters, and higher integers indicating equality constrains. For multiple groups, this argument can be a list or array with each element/slice encoding such a matrix.

lowertri_epsilon_within

Only used when within_residual = "chol". Can be "full", "diag", or a typical model matrix with 0s indicating parameters constrained to zero, 1s indicating free parameters, and higher integers indicating equality constrains. For multiple groups, this argument can be a list or array with each element/slice encoding such a matrix.

omega_zeta_between

Only used when between_latent = "ggm". Can be "full", "zero", or a typical model matrix with 0s indicating parameters constrained to zero, 1s indicating free parameters, and higher integers indicating equality constrains. For multiple groups, this argument can be a list or array with each element/slice encoding such a matrix.

delta_zeta_between

Only used when between_latent = "ggm". Can be "diag", "zero" (not recommended), or a typical model matrix with 0s indicating parameters constrained to zero, 1s indicating free parameters, and higher integers indicating equality constrains. For multiple groups, this argument can be a list or array with each element/slice encoding such a matrix.

kappa_zeta_between

Only used when between_latent = "prec". Can be "full", "diag", or a typical model matrix with 0s indicating parameters constrained to zero, 1s indicating free parameters, and higher integers indicating equality constrains. For multiple groups, this argument can be a list or array with each element/slice encoding such a matrix.

sigma_zeta_between

Only used when between_latent = "cov". Can be "full", "diag", or a typical model matrix with 0s indicating parameters constrained to zero, 1s indicating free parameters, and higher integers indicating equality constrains. For multiple groups, this argument can be a list or array with each element/slice encoding such a matrix.

lowertri_zeta_between

Only used when between_latent = "chol". Can be "full", "diag", or a typical model matrix with 0s indicating parameters constrained to zero, 1s indicating free parameters, and higher integers indicating equality constrains. For multiple groups, this argument can be a list or array with each element/slice encoding such a matrix.

omega_epsilon_between

Only used when between_residual = "ggm". Can be "full", "zero", or a typical model matrix with 0s indicating parameters constrained to zero, 1s indicating free parameters, and higher integers indicating equality constrains. For multiple groups, this argument can be a list or array with each element/slice encoding such a matrix.

delta_epsilon_between

Only used when between_residual = "ggm". Can be "diag", "zero" (not recommended), or a typical model matrix with 0s indicating parameters constrained to zero, 1s indicating free parameters, and higher integers indicating equality constrains. For multiple groups, this argument can be a list or array with each element/slice encoding such a matrix.

kappa_epsilon_between

Only used when between_residual = "prec". Can be "full", "diag", or a typical model matrix with 0s indicating parameters constrained to zero, 1s indicating free parameters, and higher integers indicating equality constrains. For multiple groups, this argument can be a list or array with each element/slice encoding such a matrix.

sigma_epsilon_between

Only used when between_residual = "cov". Can be "full", "diag", or a typical model matrix with 0s indicating parameters constrained to zero, 1s indicating free parameters, and higher integers indicating equality constrains. For multiple groups, this argument can be a list or array with each element/slice encoding such a matrix.

lowertri_epsilon_between

Only used when between_residual = "chol". Can be "full", "diag", or a typical model matrix with 0s indicating parameters constrained to zero, 1s indicating free parameters, and higher integers indicating equality constrains. For multiple groups, this argument can be a list or array with each element/slice encoding such a matrix.

nu

Optional vector encoding the intercepts of the observed variables. Set elements to 0 to indicate fixed to zero constrains, 1 to indicate free intercepts, and higher integers to indicate equality constrains. For multiple groups, this argument can be a list or array with each element/column encoding such a vector.

mu_eta

Optional vector encoding the means of the latent variables. Set elements to 0 to indicate fixed to zero constrains, 1 to indicate free intercepts, and higher integers to indicate equality constrains. For multiple groups, this argument can be a list or array with each element/column encoding such a vector.

identify

Logical, should the model be automatically identified?

identification

Type of identification used. "loadings" to fix the first factor loadings to 1, and "variance" to fix the diagonal of the latent variable model matrix (sigma_zeta, lowertri_zeta, delta_zeta or kappa_zeta) to 1.

latents

An optional character vector with names of the latent variables.

groups

An optional string indicating the name of the group variable in data.

covs

A sample variance–covariance matrix, or a list/array of such matrices for multiple groups. IMPORTANT NOTE: psychonetrics expects the maximum likelihood (ML) covariance matrix, which is NOT obtained from cov directly. Manually rescale the result of cov with (nobs - 1)/nobs to obtain the ML covariance matrix.

means

A vector of sample means, or a list/matrix containing such vectors for multiple groups.

nobs

The number of observations used in covs and means, or a vector of such numbers of observations for multiple groups.

start

Start value specification. Can be either a string or a psychonetrics model. If it is a string, "version2" indicates the latest version of start value computation, "version1" indicates start values as they were computed up to version 0.11, and "simple" indicate simple starting values. If this is a psychonetrics model the starting values will be based on the ouptut. This can be useful, for example, if you first estimate a model with matrices set to a Cholesky decomposition, then use those values as start values for estimating Gaussian graphical models.

missing

How should missingness be handled in computing the sample covariances and number of observations when data is used. Can be "listwise" for listwise deletion, or "pairwise" for pairwise deletion.

equal

A character vector indicating which matrices should be constrained equal across groups.

baseline_saturated

A logical indicating if the baseline and saturated model should be included. Mostly used internally and NOT Recommended to be used manually.

estimator

The estimator to be used. Currently implemented are "ML" for maximum likelihood estimation, "FIML" for full-information maximum likelihood estimation, "ULS" for unweighted least squares estimation, "WLS" for weighted least squares estimation, and "DWLS" for diagonally weighted least squares estimation.

optimizer

The optimizer to be used. Can be one of "nlminb" (the default R nlminb function), "ucminf" (from the optimr package), and C++ based optimizers "cpp_L-BFGS-B", "cpp_BFGS", "cpp_CG", "cpp_SANN", and "cpp_Nelder-Mead". The C++ optimizers are faster but slightly less stable. Defaults to "nlminb".

storedata

Logical, should the raw data be stored? Needed for bootstrapping (see bootstrap).

verbose

Logical, should progress be printed to the console?

sampleStats

An optional sample statistics object. Mostly used internally.

covtype

If 'covs' is used, this is the type of covariance (maximum likelihood or unbiased) the input covariance matrix represents. Set to "ML" for maximum likelihood estimates (denominator n) and "UB" to unbiased estimates (denominator n-1). The default will try to find the type used, by investigating which is most likely to result from integer valued datasets.

baseline

What baseline model should be used? "stationary_random_intercept" includes both within- and between person variances constrained equal across time (default), "stationary" only includes within-person variances constrained equal across time, "independence" (default up to version 0.11) includes a variance for every variable at every time point (not constrained equal across time), and "none" includes no baseline model.

bootstrap

Should the data be bootstrapped? If TRUE the data are resampled and a bootstrap sample is created. These must be aggregated using aggregate_bootstraps! Can be TRUE or FALSE. Can also be "nonparametric" (which sets boot_sub = 1 and boot_resample = TRUE) or "case" (which sets boot_sub = 0.75 and boot_resample = FALSE).

boot_sub

Proportion of cases to be subsampled (round(boot_sub * N)).

boot_resample

Logical, should the bootstrap be with replacement (TRUE) or without replacement (FALSE)

...

Arguments sent to dlvm1.

Value

An object of the class psychonetrics (psychonetrics-class)

Author(s)

Sacha Epskamp

Examples

library("dplyr")

# Smoke data cov matrix, based on LISS data panel https://www.dataarchive.lissdata.nl
smoke <- structure(c(47.2361758611759, 43.5366809116809, 41.0057465682466, 
                     43.5366809116809, 57.9789886039886, 47.6992521367521, 
                     41.0057465682466, 
                     47.6992521367521, 53.0669434731935), .Dim = c(3L, 3L), 
                   .Dimnames = list(
                       c("smoke2008", "smoke2009", "smoke2010"), c("smoke2008", 
                   "smoke2009", "smoke2010")))

# Design matrix:
design <- matrix(rownames(smoke),1,3)

# Form model:
mod <- panelvar(vars = design, 
                covs = smoke, nobs = 352
)


# Run model:
mod <- mod %>% runmodel

# Evaluate fit:
mod %>% fit

Model matrices used in derivatives

Description

These matrices are used in the analytic gradients

Usage

duplicationMatrix(n, diag = TRUE)

eliminationMatrix(n, diag = TRUE)

diagonalizationMatrix(n)

Arguments

n

Number of rows and columns in the original matrix

diag

Logical indicating if the diagonal should be included (set to FALSE for derivative of vech(x))

Value

A sparse matrix

Author(s)

Sacha Epskamp

Examples

# Duplication matrix for 10 variables:
duplicationMatrix(10)

# Elimination matrix for 10 variables:
eliminationMatrix(10)

# Diagonailzation matrix for 10 variables:
diagonalizationMatrix(10)

Reset starting values to simple defaults

Description

This function overwrites the starting values to simple defaults. This can help in cases where optimization fails.

Usage

emergencystart(x)

Arguments

x

A psychonetrics model.

Value

A psychonetrics model.

Author(s)

Sacha Epskamp


Ergodic Subspace Analysis

Description

These functions implement Ergodic Subspace Analysis by von Oertzen, Schmiedek and Voelkle (2020). The functions can be used on the output of a dlvm1 model, or manually by supplying a within persons and between persons variance-covariance matrix.

Usage

esa(x, cutoff = 0.1,
    between = c("crosssection", "between"))
esa_manual(sigma_wp, sigma_bp, cutoff = 0.1)
## S3 method for class 'esa'
print(x, printref = TRUE, ...)
## S3 method for class 'esa_manual'
print(x, printref = TRUE, ...)
## S3 method for class 'esa'
plot(x, plot = c("observed", "latent"), ...)
## S3 method for class 'esa_manual'
plot(x,  ...)

Arguments

x

Output of a dlvm1 model

sigma_wp

Manual within-person variance-covariance matrix

sigma_bp

Manual between-person variance-covariance matrix

cutoff

Cutoff used to determine ergodicity

printref

Logical, should the reference be printed?

plot

Should ergodicity of observed or latent variables be plotted?

between

Should the between-persons variance-covariance matrix be based on exected cross-sectional or between-person relations

...

Not used

Value

For each group a esa_manual object with the following elements:

ergodicity

Ergodicity values of each component

Q_esa

Component loadings

V_bp

Between persons subspace

V_ergodic

Ergodic subspace

V_wp

Within person subspace

cutoff

Cutoff value used

Author(s)

Sacha Epskamp <[email protected]>

References

von Oertzen, T., Schmiedek, F., and Voelkle, M. C. (2020). Ergodic Subspace Analysis. Journal of Intelligence, 8(1), 3.


Compute factor scores

Description

Currently, only the lvm framework with single group and no missing data is supported.

Usage

factorscores(data, model, method = c("bartlett", "regression"))

Arguments

data

Dataset to compute factor scores for

model

A psychonetrics model

method

The method to use: "regression" or "bartlett"

Author(s)

Sacha Epskamp <[email protected]>


Print fit indices

Description

This function will print all fit indices of the model/

Usage

fit(x)

Arguments

x

A psychonetrics model.

Value

Invisibly returns a data frame with fit measure estimates.

Author(s)

Sacha Epskamp

Examples

# Load bfi data from psych package:
library("psychTools")
data(bfi)

# Also load dplyr for the pipe operator:
library("dplyr")

# Let's take the agreeableness items, and gender:
ConsData <- bfi %>% 
  select(A1:A5, gender) %>% 
  na.omit # Let's remove missingness (otherwise use Estimator = "FIML)

# Define variables:
vars <- names(ConsData)[1:5]

# Let's fit an empty GGM:
mod0 <- ggm(ConsData, vars = vars, omega = "zero")

# Run model:
mod0 <- mod0 %>% runmodel

# Inspect fit:
mod0 %>% fit # Pretty bad fit...

Parameters modification

Description

The fixpar function can be used to fix a parameter to some value (Typically zero), and the freepar function can be used to free a parameter from being fixed to a value.

Usage

fixpar(x, matrix, row, col, value = 0, group, verbose, 
        log = TRUE, runmodel = FALSE, ...)

freepar(x, matrix, row, col, start, group, verbose, log =
        TRUE, runmodel = FALSE, startEPC = TRUE, ...)

Arguments

x

A psychonetrics model.

matrix

String indicating the matrix of the parameter

row

Integer or string indicating the row of the matrix of the parameter

col

Integer or string indicating the column of the matrix of the parameter

value

Used in fixpar to indicate the value to which a parameters is constrained

start

Used in freepar to indicate the starting value of the parameter

group

Integer indicating the group of the parameter to be constrained

verbose

Logical, should messages be printed?

log

Logical, should the log be updated?

runmodel

Logical, should the model be updated?

startEPC

Logical, should the starting value be set at the expected parameter change?

...

Arguments sent to runmodel

Value

An object of the class psychonetrics (psychonetrics-class)

Author(s)

Sacha Epskamp


Attempt to Fix Starting Values

Description

This function attempts to fix starting values by comparing the analytic gradient to a numerically approximated gradient. Parameters with a difference between the analytic and numeric gradient that exceeds 'maxdiff' will be reduced by a factor of 'reduce' in each iteration until the average absolute difference between analytic and numeric gradients is lower than 'tol'. Only off-diagonal elements in omega, sigma, kappa, lowertri or rho matrices or any element in beta matrices are adjusted.

Usage

fixstart(x, reduce = 0.5, maxdiff = 0.1, tol = 0.01, maxtry = 25)

Arguments

x

A 'psychonetrics' model

reduce

The factor with which problematic parameters are reduced in each iteration.

maxdiff

Maximum difference between analytic and numeric gradient to be considered problematic.

tol

Average absolute difference between analytic and numeric gradient that is considered acceptable.

maxtry

Maximum number of iterations to attempt to fix starting values.

Author(s)

Sacha Epskamp


Generate data from a fitted psychonetrics object

Description

This function will generate new data from the estimated mean and variance-covariance structure of a psychonetrics model.

Usage

generate(x, n = 500)

Arguments

x

A psychonetrics model.

n

Number of cases to sample per group.

Value

A data frame with simulated data

Author(s)

Sacha Epskamp


Extract an estimated matrix

Description

This function will extract an estimated matrix, and will either return a single matrix for single group models or a list of such matrices for multiple group models.

Usage

getmatrix(x, matrix, group, threshold = FALSE, alpha = 0.01,
           adjust = c("none", "holm", "hochberg", "hommel",
           "bonferroni", "BH", "BY", "fdr"), mode = c("tested",
           "all"), diag = TRUE)

Arguments

x

A psychonetrics model.

matrix

String indicating the matrix to be extracted.

group

Integer indicating the group for the matrix to be extracted.

threshold

Logical. Should the matrix be thresholded (non-significant values set to zero? Can also be a value with an absolute threshold below wich parameters are set to zero.)

alpha

Significance level to use.

adjust

p-value adjustment method to use. See p.adjust.

mode

Mode for adjusting for multiple comparisons. Should all parameters be considered as the total number of tests or only the tested parameters (parameters of interest)?

diag

Set to FALSE to set diagonal elements to zero.

Value

A matrix of parameter estimates, of a list of such matrices for multiple group models.

Author(s)

Sacha Epskamp

Examples

# Load bfi data from psych package:
library("psychTools")
data(bfi)

# Also load dplyr for the pipe operator:
library("dplyr")

# Let's take the agreeableness items, and gender:
ConsData <- bfi %>% 
  select(A1:A5, gender) %>% 
  na.omit # Let's remove missingness (otherwise use Estimator = "FIML)

# Define variables:
vars <- names(ConsData)[1:5]

# Let's fit a full GGM:
mod <- ggm(ConsData, vars = vars, omega = "full")

# Run model:
mod <- mod %>% runmodel

# Obtain network:
mod %>% getmatrix("omega")

Obtain the asymptotic covariance matrix

Description

This function can be used to obtain the estimated asymptotic covariance matrix from a psychonetrics object.

Usage

getVCOV(model, approximate_SEs = FALSE)

Arguments

model

A psychonetrics model.

approximate_SEs

Logical, should standard errors be approximated? If true, an approximate matrix inverse of the Fischer information is used to obtain the standard errors.

Value

This function returns a matrix.

Author(s)

Sacha Epskamp


Group equality constrains

Description

The groupequal function constrains parameters equal across groups, and the groupfree function frees equality constrains across groups.

Usage

groupequal(x, matrix, row, col, verbose, log = TRUE, runmodel =
                    FALSE, identify = TRUE, ...)

groupfree(x, matrix, row, col, verbose, log = TRUE, runmodel =
                    FALSE, identify = TRUE, ...)

Arguments

x

A psychonetrics model.

matrix

String indicating the matrix of the parameter

row

Integer or string indicating the row of the matrix of the parameter

col

Integer or string indicating the column of the matrix of the parameter

verbose

Logical, should messages be printed?

log

Logical, should the log be updated?

runmodel

Logical, should the model be updated?

identify

Logical, should the model be identified?

...

Arguments sent to runmodel

Value

An object of the class psychonetrics (psychonetrics-class)

Author(s)

Sacha Epskamp


Ising model

Description

This is the family of Ising models fit to dichotomous datasets. Note that the input matters (see also https://arxiv.org/abs/1811.02916) in this model! Models based on a dataset that is encoded with -1 and 1 are not entirely equivalent to models based on datasets encoded with 0 and 1 (non-equivalences occur in multi-group settings with equality constrains).

Usage

Ising(data, omega = "full", tau, beta, vars, groups, covs,
                   means, nobs, covtype = c("choose", "ML", "UB"),
                   responses, missing = "listwise", equal = "none",
                   baseline_saturated = TRUE, estimator = "default",
                   optimizer, storedata = FALSE, WLS.W, sampleStats,
                   identify = TRUE, verbose = FALSE, maxNodes = 20,
                   min_sum = -Inf, bootstrap = FALSE, boot_sub,
                   boot_resample)

Arguments

data

A data frame encoding the data used in the analysis. Can be missing if covs and nobs are supplied.

omega

The network structure. Either "full" to estimate every element freely, "zero" to set all elements to zero, or a matrix of the dimensions nNode x nNode with 0 encoding a fixed to zero element, 1 encoding a free to estimate element, and higher integers encoding equality constrains. For multiple groups, this argument can be a list or array with each element/slice encoding such a matrix.

tau

Optional vector encoding the threshold/intercept structure. Set elements to 0 to indicate fixed to zero constrains, 1 to indicate free intercepts, and higher integers to indicate equality constrains. For multiple groups, this argument can be a list or array with each element/column encoding such a vector.

beta

Optional scalar encoding the inverse temperature. 1 indicate free beta parameters, and higher integers to indicate equality constrains. For multiple groups, this argument can be a list or array with each element/column encoding such scalers.

vars

An optional character vector encoding the variables used in the analyis. Must equal names of the dataset in data.

groups

An optional character vector encoding the variables used in the analyis. Must equal names of the dataset in data.

covs

A sample variance–covariance matrix, or a list/array of such matrices for multiple groups. Make sure covtype argument is set correctly to the type of covariances used.

means

A vector of sample means, or a list/matrix containing such vectors for multiple groups.

nobs

The number of observations used in covs and means, or a vector of such numbers of observations for multiple groups.

covtype

If 'covs' is used, this is the type of covariance (maximum likelihood or unbiased) the input covariance matrix represents. Set to "ML" for maximum likelihood estimates (denominator n) and "UB" to unbiased estimates (denominator n-1). The default will try to find the type used, by investigating which is most likely to result from integer valued datasets.

responses

A vector of dichotemous responses used (e.g., c(-1,1) or c(0,1). Only needed when 'covs' is used.)

missing

How should missingness be handled in computing the sample covariances and number of observations when data is used. Can be "listwise" for listwise deletion, or "pairwise" for pairwise deletion. NOT RECOMMENDED TO BE USED YET IN ISING MODEL.

equal

A character vector indicating which matrices should be constrained equal across groups.

baseline_saturated

A logical indicating if the baseline and saturated model should be included. Mostly used internally and NOT Recommended to be used manually.

estimator

The estimator to be used. Currently implemented are "ML" for maximum likelihood estimation, "FIML" for full-information maximum likelihood estimation, "ULS" for unweighted least squares estimation, "WLS" for weighted least squares estimation, and "DWLS" for diagonally weighted least squares estimation. Only ML estimation is currently supported for the Ising model.

optimizer

The optimizer to be used. Can be one of "nlminb" (the default R nlminb function), "ucminf" (from the optimr package), and C++ based optimizers "cpp_L-BFGS-B", "cpp_BFGS", "cpp_CG", "cpp_SANN", and "cpp_Nelder-Mead". The C++ optimizers are faster but slightly less stable. Defaults to "nlminb".

storedata

Logical, should the raw data be stored? Needed for bootstrapping (see bootstrap).

WLS.W

Optional WLS weights matrix. CURRENTLY NOT USED.

sampleStats

An optional sample statistics object. Mostly used internally.

identify

Logical, should the model be identified?

verbose

Logical, should messages be printed?

maxNodes

The maximum number of nodes allowed in the analysis. This function will stop with an error if more nodes are used (it is not recommended to set this higher).

min_sum

The minimum sum score that is artifically possible in the dataset. Defaults to -Inf. Set this only if you know a lower sum score is not possible in the data, for example due to selection bias.

bootstrap

Should the data be bootstrapped? If TRUE the data are resampled and a bootstrap sample is created. These must be aggregated using aggregate_bootstraps! Can be TRUE or FALSE. Can also be "nonparametric" (which sets boot_sub = 1 and boot_resample = TRUE) or "case" (which sets boot_sub = 0.75 and boot_resample = FALSE).

boot_sub

Proportion of cases to be subsampled (round(boot_sub * N)).

boot_resample

Logical, should the bootstrap be with replacement (TRUE) or without replacement (FALSE)

Details

The Ising Model takes the following form:

Pr(Y=y)=exp(βH(y;τ,Ω))Z(τ,Ω)\Pr(\boldsymbol{Y} = \boldsymbol{y}) = \frac{\exp\left( -\beta H\left(\boldsymbol{y}; \boldsymbol{\tau}, \boldsymbol{\Omega}\right)\right)}{Z(\boldsymbol{\tau}, \boldsymbol{\Omega})}

With Hamiltonian:

H(y;τ,Ω)=i=1mτiyii=2mj=1i1ωijyiyj.H\left(\boldsymbol{y}; \boldsymbol{\tau}, \boldsymbol{\Omega}\right) = -\sum_{i=1}^{m} \tau_i y_{i} - \sum_{i=2}^{m} \sum_{j=1}^{i-1} \omega_{ij} y_i y_j.

And Z representing the partition function or normalizing constant.

Value

An object of the class psychonetrics

Author(s)

Sacha Epskamp <[email protected]>

References

Epskamp, S., Maris, G., Waldorp, L. J., & Borsboom, D. (2018). Network Psychometrics. In: Irwing, P., Hughes, D., & Booth, T. (Eds.), The Wiley Handbook of Psychometric Testing, 2 Volume Set: A Multidisciplinary Reference on Survey, Scale and Test Development. New York: Wiley.

Examples

library("dplyr")
data("Jonas")

# Variables to use:
vars <- names(Jonas)[1:10]

# Arranged groups to put unfamiliar group first (beta constrained to 1):
Jonas <- Jonas[order(Jonas$group),]

# Form saturated model:
model1 <- Ising(Jonas, vars = vars, groups = "group")

# Run model:
model1 <- model1 %>% runmodel(approximate_SEs = TRUE)
# We approximate the SEs because there are zeroes in the crosstables
# of people that know Jonas. This leads to uninterpretable edge
# estimates, but as can be seen below only in the model with
# non-equal estimates across groups.

# Prune-stepup to find a sparse model:
model1b <- model1 %>% prune(alpha = 0.05) %>%  stepup(alpha = 0.05)

# Equal networks:
suppressWarnings(
  model2 <- model1 %>% groupequal("omega") %>% runmodel
)

# Prune-stepup to find a sparse model:
model2b <- model2 %>% prune(alpha = 0.05) %>% stepup(mi = "mi_equal", alpha = 0.05)

# Equal thresholds:
model3 <- model2 %>% groupequal("tau") %>% runmodel

# Prune-stepup to find a sparse model:
model3b <- model3 %>% prune(alpha = 0.05) %>% stepup(mi = "mi_equal", alpha = 0.05)

# Equal beta:
model4 <- model3 %>% groupequal("beta") %>% runmodel

# Prune-stepup to find a sparse model:
model4b <- model4 %>% prune(alpha = 0.05) %>% stepup(mi = "mi_equal", alpha = 0.05)

# Compare all models:
compare(
  `1. all parameters free (dense)` = model1,
  `2. all parameters free (sparse)` = model1b,
  `3. equal networks (dense)` = model2,
  `4. equal networks (sparse)` = model2b,
  `5. equal networks and thresholds (dense)` = model3,
  `6. equal networks and thresholds (sparse)` = model3b,
  `7. all parameters equal (dense)` = model4,
  `8. all parameters equal (sparse)` = model4b
) %>% arrange(BIC)

Jonas dataset

Description

Responses of 10 attitude items towards a researcher named Jonas. Participants were shown three photos of Jonas with the text: "This is Jonas, a researcher from Germany who is now becoming a PhD in Psychology". Subsequently, the participants had to answer 10 yes / no questions starting with "I believe that Jonas...", as well as rate their familliarity with Jonas. The sample consists of people familiar with Jonas and not familiar with Jonas, and allows for testing Attitudinal Entropy Framework <doi:10.1080/1047840X.2018.1537246>.

Usage

data("Jonas")

Format

A data frame with 215 observations on the following 12 variables.

scientist

... is a good scientist

jeans

... Is a person that wears beautiful jeans

cares

... really cares about people like you

economics

... would solve our economic problems

hardworking

... is hardworking

honest

... is honest

intouch

... is in touch with ordinary people

knowledgeable

... is knowledgeable

makeupmind

... can't make up his mind

getsthingsdone

... gets things done

familiar

Answers to the question "How familiar are you with Jonas?" (three responses possible)

group

The question 'familiar' categorized in two groups ("Knows Jonas" and "Doesn't Know Jonas")

Examples

data(Jonas)

Latnet growth curve model

Description

Wrapper to lvm to specify a latent growth curve model.

Usage

latentgrowth(vars, time = seq_len(ncol(vars)) - 1, covariates =
                   character(0), covariates_as = c("regression",
                   "covariance"), ...)

Arguments

vars

Different from in other psychonetrics models, this must be a *matrix* with each row indicating a variable and each column indicating a measurement. The matrix must be filled with names of the variables in the dataset corresponding to variable i at wave j. NAs can be used to indicate missing waves. The rownames of this matrix will be used as variable names.

time

A vector with the encoding of each measurement (e.g., 0, 1, 2, 3).

covariates

A vector with strings indicating names of between-person covariate variables in the data

covariates_as

Should covariates be included as regressions or actual covariates?

...

Arguments sent to lvm

Details

See https://github.com/SachaEpskamp/SEM-code-examples/tree/master/Latent_growth_examples/psychonetrics for examples

Value

An object of the class psychonetrics (psychonetrics-class). See for an example https://github.com/SachaEpskamp/SEM-code-examples/tree/master/Latent_growth_examples/psychonetrics.

Author(s)

Sacha Epskamp

Examples

library("dplyr")

# Smoke data cov matrix, based on LISS data panel https://www.dataarchive.lissdata.nl
smoke <- structure(c(47.2361758611759, 43.5366809116809, 41.0057465682466, 
                     43.5366809116809, 57.9789886039886, 47.6992521367521, 
                     41.0057465682466, 
                     47.6992521367521, 53.0669434731935), .Dim = c(3L, 3L), 
                   .Dimnames = list(
                       c("smoke2008", "smoke2009", "smoke2010"), c("smoke2008", 
                   "smoke2009", "smoke2010")))

# Design matrix:
design <- matrix(rownames(smoke),1,3)

# Form model:
mod <- latentgrowth(vars = design, 
                covs = smoke, nobs = 352
)

## Not run: 
# Run model:
mod <- mod %>% runmodel

# Evaluate fit:
mod %>% fit

# Look at parameters:
mod %>% parameters

## End(Not run)

Retrieve the psychonetrics logbook

Description

This function can be used to retrieve the logbook of a 'psychonetrics' object.

Usage

logbook(x, log = TRUE)

Arguments

x

A 'psychonetrics' object.

log

Logical, should the entry that the logbook is accessed be added?

Author(s)

Sacha Epskamp


Continuous latent variable family of psychonetrics models

Description

This is the family of models that models the data as a structural equation model (SEM), allowing the latent and residual variance-covariance matrices to be further modeled as networks. The latent and residual arguments can be used to define what latent and residual models are used respectively: "cov" (default) models a variance-covariance matrix directly, "chol" models a Cholesky decomposition, "prec" models a precision matrix, and "ggm" models a Gaussian graphical model (Epskamp, Rhemtulla and Borsboom, 2017). The wrapper lnm() sets latent = "ggm" for the latent network model (LNM), the wrapper rnm() sets residual = "ggm" for the residual network model (RNM), and the wrapper lrnm() combines the LNM and RNM.

Usage

lvm(data, lambda, latent = c("cov", "chol", "prec",
                   "ggm"), residual = c("cov", "chol", "prec", "ggm"),
                   sigma_zeta = "full", kappa_zeta = "full", omega_zeta =
                   "full", lowertri_zeta = "full", delta_zeta = "full",
                   sigma_epsilon = "diag", kappa_epsilon = "diag",
                   omega_epsilon = "zero", lowertri_epsilon = "diag",
                   delta_epsilon = "diag", beta = "zero", nu, nu_eta,
                   identify = TRUE, identification = c("loadings",
                   "variance"), vars, latents, groups, covs, means, nobs,
                   missing = "listwise", equal = "none",
                   baseline_saturated = TRUE, estimator = "ML",
                   optimizer, storedata = FALSE, WLS.W, covtype =
                   c("choose", "ML", "UB"), standardize = c("none", "z",
                   "quantile"), sampleStats, verbose = FALSE,
                   simplelambdastart = FALSE, bootstrap = FALSE,
                   boot_sub, boot_resample)

lnm(...)
rnm(...)
lrnm(...)

Arguments

data

A data frame encoding the data used in the analysis. Can be missing if covs and nobs are supplied.

lambda

A model matrix encoding the factor loading structure. Each row indicates an indicator and each column a latent. A 0 encodes a fixed to zero element, a 1 encoding a free to estimate element, and higher integers encoding equality constrains. For multiple groups, this argument can be a list or array with each element/slice encoding such a matrix.

latent

The type of latent model used. See description.

residual

The type of residual model used. See description.

sigma_zeta

Only used when latent = "cov". Either "full" to estimate every element freely, "diag" to only include diagonal elements, or a matrix of the dimensions node x node with 0 encoding a fixed to zero element, 1 encoding a free to estimate element, and higher integers encoding equality constrains. For multiple groups, this argument can be a list or array with each element/slice encoding such a matrix.

kappa_zeta

Only used when latent = "prec". Either "full" to estimate every element freely, "diag" to only include diagonal elements, or a matrix of the dimensions node x node with 0 encoding a fixed to zero element, 1 encoding a free to estimate element, and higher integers encoding equality constrains. For multiple groups, this argument can be a list or array with each element/slice encoding such a matrix.

omega_zeta

Only used when latent = "ggm". Either "full" to estimate every element freely, "zero" to set all elements to zero, or a matrix of the dimensions node x node with 0 encoding a fixed to zero element, 1 encoding a free to estimate element, and higher integers encoding equality constrains. For multiple groups, this argument can be a list or array with each element/slice encoding such a matrix.

lowertri_zeta

Only used when latent = "chol". Either "full" to estimate every element freely, "diag" to only include diagonal elements, or a matrix of the dimensions node x node with 0 encoding a fixed to zero element, 1 encoding a free to estimate element, and higher integers encoding equality constrains. For multiple groups, this argument can be a list or array with each element/slice encoding such a matrix.

delta_zeta

Only used when latent = "ggm". Either "diag" or "zero", or a matrix of the dimensions node x node with 0 encoding a fixed to zero element, 1 encoding a free to estimate element, and higher integers encoding equality constrains. For multiple groups, this argument can be a list or array with each element/slice encoding such a matrix.

sigma_epsilon

Only used when residual = "cov". Either "full" to estimate every element freely, "diag" to only include diagonal elements, or a matrix of the dimensions node x node with 0 encoding a fixed to zero element, 1 encoding a free to estimate element, and higher integers encoding equality constrains. For multiple groups, this argument can be a list or array with each element/slice encoding such a matrix.

kappa_epsilon

Only used when residual = "prec". Either "full" to estimate every element freely, "diag" to only include diagonal elements, or a matrix of the dimensions node x node with 0 encoding a fixed to zero element, 1 encoding a free to estimate element, and higher integers encoding equality constrains. For multiple groups, this argument can be a list or array with each element/slice encoding such a matrix.

omega_epsilon

Only used when residual = "ggm". Either "full" to estimate every element freely, "zero" to set all elements to zero, or a matrix of the dimensions node x node with 0 encoding a fixed to zero element, 1 encoding a free to estimate element, and higher integers encoding equality constrains. For multiple groups, this argument can be a list or array with each element/slice encoding such a matrix.

lowertri_epsilon

Only used when residual = "chol". Either "full" to estimate every element freely, "diag" to only include diagonal elements, or a matrix of the dimensions node x node with 0 encoding a fixed to zero element, 1 encoding a free to estimate element, and higher integers encoding equality constrains. For multiple groups, this argument can be a list or array with each element/slice encoding such a matrix.

delta_epsilon

Only used when residual = "ggm". Either "diag" or "zero", or a matrix of the dimensions node x node with 0 encoding a fixed to zero element, 1 encoding a free to estimate element, and higher integers encoding equality constrains. For multiple groups, this argument can be a list or array with each element/slice encoding such a matrix.

beta

A model matrix encoding the structural relations between latent variables. A 0 encodes a fixed to zero element, a 1 encoding a free to estimate element, and higher integers encoding equality constrains. For multiple groups, this argument can be a list or array with each element/slice encoding such a matrix.

nu

Optional vector encoding the intercepts of the observed variables. Set elements to 0 to indicate fixed to zero constrains, 1 to indicate free intercepts, and higher integers to indicate equality constrains. For multiple groups, this argument can be a list or array with each element/column encoding such a vector.

nu_eta

Optional vector encoding the intercepts of the latent variables. Set elements to 0 to indicate fixed to zero constrains, 1 to indicate free intercepts, and higher integers to indicate equality constrains. For multiple groups, this argument can be a list or array with each element/column encoding such a vector.

identify

Logical, should the model be automatically identified?

identification

Type of identification used. "loadings" to fix the first factor loadings to 1, and "variance" to fix the diagonal of the latent variable model matrix (sigma_zeta, lowertri_zeta, delta_zeta or kappa_zeta) to 1.

vars

An optional character vector encoding the variables used in the analysis. Must equal names of the dataset in data.

latents

An optional character vector with names of the latent variables.

groups

An optional string indicating the name of the group variable in data.

covs

A sample variance–covariance matrix, or a list/array of such matrices for multiple groups. Make sure covtype argument is set correctly to the type of covariances used.

means

A vector of sample means, or a list/matrix containing such vectors for multiple groups.

nobs

The number of observations used in covs and means, or a vector of such numbers of observations for multiple groups.

missing

How should missingness be handled in computing the sample covariances and number of observations when data is used. Can be "listwise" for listwise deletion, or "pairwise" for pairwise deletion.

equal

A character vector indicating which matrices should be constrained equal across groups.

baseline_saturated

A logical indicating if the baseline and saturated model should be included. Mostly used internally and NOT Recommended to be used manually.

estimator

The estimator to be used. Currently implemented are "ML" for maximum likelihood estimation, "FIML" for full-information maximum likelihood estimation, "ULS" for unweighted least squares estimation, "WLS" for weighted least squares estimation, and "DWLS" for diagonally weighted least squares estimation.

optimizer

The optimizer to be used. Can be one of "nlminb" (the default R nlminb function), "ucminf" (from the optimr package), and C++ based optimizers "cpp_L-BFGS-B", "cpp_BFGS", "cpp_CG", "cpp_SANN", and "cpp_Nelder-Mead". The C++ optimizers are faster but slightly less stable. Defaults to "nlminb".

storedata

Logical, should the raw data be stored? Needed for bootstrapping (see bootstrap).

verbose

Logical, should progress be printed to the console?

WLS.W

The weights matrix used in WLS estimation (experimental)

sampleStats

An optional sample statistics object. Mostly used internally.

covtype

If 'covs' is used, this is the type of covariance (maximum likelihood or unbiased) the input covariance matrix represents. Set to "ML" for maximum likelihood estimates (denominator n) and "UB" to unbiased estimates (denominator n-1). The default will try to find the type used, by investigating which is most likely to result from integer valued datasets.

standardize

Which standardization method should be used? "none" (default) for no standardization, "z" for z-scores, and "quantile" for a non-parametric transformation to the quantiles of the marginal standard normal distribution.

simplelambdastart

Logical, should simple start values be used for lambda? Setting this to TRUE can avoid some estimation problems.

bootstrap

Should the data be bootstrapped? If TRUE the data are resampled and a bootstrap sample is created. These must be aggregated using aggregate_bootstraps! Can be TRUE or FALSE. Can also be "nonparametric" (which sets boot_sub = 1 and boot_resample = TRUE) or "case" (which sets boot_sub = 0.75 and boot_resample = FALSE).

boot_sub

Proportion of cases to be subsampled (round(boot_sub * N)).

boot_resample

Logical, should the bootstrap be with replacement (TRUE) or without replacement (FALSE)

...

Arguments sent to varcov

Details

The model used in this family is:

var(y)=Λ(IB)1Σζ(IB)1Λ+Σε\mathrm{var}( \boldsymbol{y} ) = \boldsymbol{\Lambda} (\boldsymbol{I} - \boldsymbol{B})^{-1} \boldsymbol{\Sigma}_{\zeta} (\boldsymbol{I} - \boldsymbol{B})^{-1\top} \boldsymbol{\Lambda}^{\top} + \boldsymbol{\Sigma}_{\varepsilon}

E(y)=ν+Λ(IB)1νeta\mathcal{E}( \boldsymbol{y} ) = \boldsymbol{\nu} + \boldsymbol{\Lambda} (\boldsymbol{I} - \boldsymbol{B})^{-1} \boldsymbol{\nu}_eta

in which the latent covariance matrix can further be modeled in three ways. With latent = "chol" as Cholesky decomposition:

Σζ=LζLζ\boldsymbol{\Sigma}_{\zeta} = \boldsymbol{L}_{\zeta}\boldsymbol{L}_{\zeta},

with latent = "prec" as Precision matrix:

Σζ=Kζ1\boldsymbol{\Sigma}_{\zeta} = \boldsymbol{K}_{\zeta}^{-1},

and finally with latent = "ggm" as Gaussian graphical model:

Σζ=Δζ(IΩζ)(1)Δζ\boldsymbol{\Sigma}_{\zeta} = \boldsymbol{\Delta}_{\zeta}(\boldsymbol{I} - \boldsymbol{\Omega}_{\zeta})^(-1) \boldsymbol{\Delta}_{\zeta}.

Likewise, the residual covariance matrix can also further be modeled in three ways. With residual = "chol" as Cholesky decomposition:

Σε=LεLε\boldsymbol{\Sigma}_{\varepsilon} = \boldsymbol{L}_{\varepsilon}\boldsymbol{L}_{\varepsilon},

with latent = "prec" as Precision matrix:

Σε=Kε1\boldsymbol{\Sigma}_{\varepsilon} = \boldsymbol{K}_{\varepsilon}^{-1},

and finally with latent = "ggm" as Gaussian graphical model:

Σε=Δε(IΩε)(1)Δε\boldsymbol{\Sigma}_{\varepsilon} = \boldsymbol{\Delta}_{\varepsilon}(\boldsymbol{I} - \boldsymbol{\Omega}_{\varepsilon})^(-1) \boldsymbol{\Delta}_{\varepsilon}.

Value

An object of the class psychonetrics (psychonetrics-class)

Author(s)

Sacha Epskamp

References

Epskamp, S., Rhemtulla, M., & Borsboom, D. (2017). Generalized network psychometrics: Combining network and latent variable models. Psychometrika, 82(4), 904-927.

Examples

library("dplyr")

### Confirmatory Factor Analysis ###

# Example also shown in https://youtu.be/Hdu5z-fwuk8

# Load data:
data(StarWars)

# Originals only:
Lambda <- matrix(1,4)

# Model:
mod0 <- lvm(StarWars, lambda = Lambda, vars = c("Q1","Q5","Q6","Q7"), 
            identification = "variance", latents = "Originals")
            
# Run model:
mod0 <- mod0 %>% runmodel

# Evaluate fit:
mod0 %>% fit


# Full analysis
# Factor loadings matrix:
Lambda <- matrix(0, 10, 3)
Lambda[1:4,1] <- 1
Lambda[c(1,5:7),2] <- 1
Lambda[c(1,8:10),3] <- 1

# Observed variables:
obsvars <- paste0("Q",1:10)

# Latents:
latents <- c("Prequels","Original","Sequels")

# Make model:
mod1 <- lvm(StarWars, lambda = Lambda, vars = obsvars, 
            identification = "variance", latents = latents)

# Run model:
mod1 <- mod1 %>% runmodel

# Look at fit:
mod1

# Look at parameter estimates:
mod1 %>% parameters

# Look at modification indices:
mod1 %>% MIs

# Add and refit:
mod2 <- mod1 %>% freepar("sigma_epsilon","Q10","Q4") %>% runmodel

# Compare:
compare(original = mod1, adjusted = mod2)

# Fit measures:
mod2 %>% fit

### Path diagrams ###
# semPlot is not (yet) supported by default, but can be used as follows:
# Load packages:
library("semPlot")

# Estimates:
lambdaEst <- getmatrix(mod2, "lambda")
psiEst <- getmatrix(mod2, "sigma_zeta")
thetaEst <- getmatrix(mod2, "sigma_epsilon")

# LISREL Model: LY = Lambda (lambda-y), TE = Theta (theta-epsilon), PS = Psi
mod <- lisrelModel(LY =  lambdaEst, PS = psiEst, TE = thetaEst)

# Plot with semPlot:
semPaths(mod, "std", "est", as.expression = "nodes")


# We can make this nicer (set whatLabels = "none" to hide labels):
semPaths(mod,

# this argument controls what the color of edges represent. In this case, 
# standardized parameters:
    what = "std", 
    
# This argument controls what the edge labels represent. In this case, parameter 
# estimates:
    whatLabels = "est", 
    
# This argument draws the node and edge labels as mathematical exprssions:    
    as.expression = "nodes", 
  
# This will plot residuals as arrows, closer to what we use in class:
    style = "lisrel",
    
# This makes the residuals larger:
    residScale = 10, 
    
# qgraph colorblind friendly theme:
    theme = "colorblind",
    
# tree layout options are "tree", "tree2", and "tree3":
    layout = "tree2", 

# This makes the latent covariances connect at a cardinal center point:
    cardinal = "lat cov",

# Changes curve into rounded straight lines:
    curvePivot = TRUE, 
    
# Size of manifest variables:
    sizeMan = 4, 
    
# Size of latent varibales:
    sizeLat = 10, 
    
# Size of edge labels:
    edge.label.cex = 1,
    
# Sets the margins:
    mar = c(9,1,8,1), 
    
# Prevents re-ordering of ovbserved variables:
    reorder = FALSE, 
    
# Width of the plot:
    width = 8, 
    
# Height of plot:
    height = 5, 

# Colors according to latents:
    groups = "latents",
    
# Pastel colors:
    pastel = TRUE, 
    
# Disable borders:
    borders = FALSE 
    )
    
# Use arguments filetype = "pdf" and filename = "semPlotExample1" to store PDF

### Latent Network Modeling ###

# Latent network model:
lnm <- lvm(StarWars, lambda = Lambda, vars = obsvars,
           latents = latents, identification = "variance",
           latent = "ggm")

# Run model:
lnm <- lnm %>% runmodel

# Look at parameters:
lnm %>% parameters

# Remove non-sig latent edge:
lnm <- lnm %>% prune(alpha = 0.05)

# Compare to the original CFA model:
compare(cfa = mod1, lnm = lnm)

# Plot network:
library("qgraph")
qgraph(lnm@modelmatrices[[1]]$omega_zeta, labels = latents,
       theme = "colorblind", vsize = 10)

# A wrapper for the latent network model is the lnm function:
lnm2 <- lnm(StarWars, lambda = Lambda, vars = obsvars,
            latents = latents, identification = "variance")
lnm2 <- lnm2 %>% runmodel %>% prune(alpha = 0.05)
compare(lnm, lnm2) # Is the same as the model before.

# I could also estimate a "residual network model", which adds partial correlations to 
# the residual level:
# This can be done using lvm(..., residal = "ggm") or with rnm(...)
rnm <- rnm(StarWars, lambda = Lambda, vars = obsvars,
           latents = latents, identification = "variance")
# Stepup search:
rnm <- rnm %>% stepup

# It will estimate the same model (with link Q10 - Q4) as above. In the case of only one 
# partial correlation, There is no difference between residual covariances (SEM) or 
# residual partial correlations (RNM).


# For more information on latent and residual network models, see:
# Epskamp, S., Rhemtulla, M.T., & Borsboom, D. Generalized Network Psychometrics: 
# Combining Network and Latent Variable Models 
# (2017). Psychometrika. doi:10.1007/s11336-017-9557-x

### Gaussian graphical models ###

# All psychonetrics functions (e.g., lvm, lnm, rnm...) allow input via a covariance 
# matrix, with the "covs" and "nobs" arguments.
# The following fits a baseline GGM network with no edges:
S <- (nrow(StarWars) - 1)/ (nrow(StarWars)) * cov(StarWars[,1:10])
ggmmod <- ggm(covs = S, nobs = nrow(StarWars))

# Run model with stepup search and pruning:
ggmmod <- ggmmod%>% prune  %>% modelsearch

# Fit measures:
ggmmod %>% fit

# Plot network:
nodeNames <- c(
"I am a huge Star Wars\nfan! (star what?)",
"I would trust this person\nwith my democracy.",
"I enjoyed the story of\nAnakin's early life.",
"The special effects in\nthis scene are awful (Battle of\nGeonosis).",
"I would trust this person\nwith my life.",
"I found Darth Vader's big\nreveal in 'Empire' one of the greatest
moments in movie history.",
"The special effects in\nthis scene are amazing (Death Star\nExplosion).",
"If possible, I would\ndefinitely buy this\ndroid.",
"The story in the Star\nWars sequels is an improvement to\nthe previous movies.",
"The special effects in\nthis scene are marvellous (Starkiller\nBase Firing)."
)
library("qgraph")
qgraph(as.matrix(ggmmod@modelmatrices[[1]]$omega), nodeNames = nodeNames, 
    legend.cex = 0.25,  theme = "colorblind", layout = "spring")

# We can actually compare this model statistically (note they are not nested) to the 
# latent variable model:
compare(original_cfa = mod1, adjusted_cfa = mod2, exploratory_ggm = ggmmod)


### Meausrement invariance ###
# Let's say we are interested in seeing if people >= 30 like the original trilogy better 
# than people < 30.
# First we can make a grouping variable:
StarWars$agegroup <- ifelse(StarWars$Q12 < 30, "young", "less young")

# Let's look at the distribution:
table(StarWars$agegroup) # Pretty even...

# Observed variables:
obsvars <- paste0("Q",1:10)

# Let's look at the mean scores:
StarWars %>% group_by(agegroup) %>% summarize_each_(funs(mean),vars = obsvars)
# Less young people seem to score higher on prequel questions and lower on other 
# questions

# Factor loadings matrix:
Lambda <- matrix(0, 10, 3)
Lambda[1:4,1] <- 1
Lambda[c(1,5:7),2] <- 1
Lambda[c(1,8:10),3] <- 1

# Residual covariances:
Theta <- diag(1, 10)
Theta[4,10] <- Theta[10,4] <- 1

# Latents:
latents <- c("Prequels","Original","Sequels")

# Make model:
mod_configural <- lvm(StarWars, lambda = Lambda, vars = obsvars,
            latents = latents, sigma_epsilon = Theta,
            identification = "variance",
            groups =  "agegroup")

# Run model:
mod_configural <- mod_configural %>% runmodel

# Look at fit:
mod_configural
mod_configural %>% fit

# Looks good, let's try weak invariance:
mod_weak <- mod_configural %>% groupequal("lambda") %>% runmodel

# Compare models:
compare(configural = mod_configural, weak = mod_weak)

# weak invariance can be accepted, let's try strong:
mod_strong <- mod_weak %>% groupequal("nu") %>% runmodel
# Means are automatically identified

# Compare models:
compare(configural = mod_configural, weak = mod_weak, strong = mod_strong)

# Questionable p-value and AIC difference, but ok BIC difference. This is quite good, but 
# let's take a look. I have not yet implemented LM tests for equality constrains, but we 
# can look at something called "equality-free" MIs:
mod_strong %>% MIs(matrices = "nu", type = "free")

# Indicates that Q10 would improve fit. We can also look at residuals:
residuals(mod_strong)

# Let's try freeing intercept 10:
mod_strong_partial <- mod_strong %>% groupfree("nu",10) %>% runmodel

# Compare all models:
compare(configural = mod_configural,
        weak = mod_weak,
        strong = mod_strong,
        strong_partial = mod_strong_partial)

# This seems worth it and lead to an acceptable model! It seems that older people find 
# the latest special effects more marvellous!
mod_strong_partial %>% getmatrix("nu")

# Now let's investigate strict invariance:
mod_strict <- mod_strong_partial %>% groupequal("sigma_epsilon") %>% runmodel

# Compare all models:
compare(configural = mod_configural,
        weak = mod_weak,
        strong_partial = mod_strong_partial,
        strict = mod_strict)
# Strict invariance can be accepted!

#  Now we can test for homogeneity!
# Are the latent variances equal?
mod_eqvar <- mod_strict %>% groupequal("sigma_zeta") %>% runmodel

# Compare:
compare(strict = mod_strict, eqvar = mod_eqvar) 

# This is acceptable. What about the means? (alpha = nu_eta)
mod_eqmeans <- mod_eqvar %>% groupequal("nu_eta") %>% runmodel

# Compare:
compare(eqvar = mod_eqvar, eqmeans = mod_eqmeans)

# Rejected! We could look at MIs again:
mod_eqmeans %>% MIs(matrices = "nu_eta", type = "free")

# Indicates the strongest effect for prequels. Let's see what happens:
eqmeans2 <- mod_eqvar %>% 
  groupequal("nu_eta",row = c("Original","Sequels")) %>% runmodel

# Compare:
compare(eqvar = mod_eqvar, eqmeans = eqmeans2)
# Questionable, what about the sequels as well?

eqmeans3 <- mod_eqvar %>% groupequal("nu_eta", row = "Original") %>% runmodel

# Compare:
compare(eqvar = mod_eqvar, eqmeans = eqmeans3)

# Still questionable.. Let's look at the mean differences:
mod_eqvar %>% getmatrix("nu_eta")

# Looks like people over 30 like the prequels better and the other two trilogies less!

Variance-covariance and GGM meta analysis

Description

Meta analysis of correlation matrices to fit a homogenous correlation matrix or Gaussian graphical model. Based on meta-analytic SEM (Jak and Cheung, 2019).

Usage

meta_varcov(cors, nobs, Vmats, Vmethod = c("individual", "pooled",
                   "metaSEM_individual", "metaSEM_weighted"), Vestimation
                   = c("averaged", "per_study"), type = c("cor", "ggm"),
                   sigma_y = "full", kappa_y = "full", omega_y = "full",
                   lowertri_y = "full", delta_y = "full", rho_y = "full",
                   SD_y = "full", randomEffects = c("chol", "cov",
                   "prec", "ggm", "cor"), sigma_randomEffects = "full",
                   kappa_randomEffects = "full", omega_randomEffects =
                   "full", lowertri_randomEffects = "full",
                   delta_randomEffects = "full", rho_randomEffects =
                   "full", SD_randomEffects = "full", vars,
                   baseline_saturated = TRUE, optimizer, estimator =
                   c("FIML", "ML"), sampleStats, verbose = FALSE,
                   bootstrap = FALSE, boot_sub, boot_resample)
  
meta_ggm(...)

Arguments

cors

A list of correlation matrices. Must contain rows and columns with NAs for variables not included in a study.

nobs

A vector with the number of observations per study.

Vmats

Optional list with 'V' matrices (sampling error variance approximations).

Vmethod

Which method should be used to apprixomate the sampling error variance?

Vestimation

How should the sampling error estimates be evaluated?

type

What to model? Currently only "cor" and "ggm" are supported.

sigma_y

Only used when type = "cov". Either "full" to estimate every element freely, "diag" to only include diagonal elements, or a matrix of the dimensions node x node with 0 encoding a fixed to zero element, 1 encoding a free to estimate element, and higher integers encoding equality constrains. For multiple groups, this argument can be a list or array with each element/slice encoding such a matrix.

kappa_y

Only used when type = "prec". Either "full" to estimate every element freely, "diag" to only include diagonal elements, or a matrix of the dimensions node x node with 0 encoding a fixed to zero element, 1 encoding a free to estimate element, and higher integers encoding equality constrains. For multiple groups, this argument can be a list or array with each element/slice encoding such a matrix.

omega_y

Only used when type = "ggm". Either "full" to estimate every element freely, "zero" to set all elements to zero, or a matrix of the dimensions node x node with 0 encoding a fixed to zero element, 1 encoding a free to estimate element, and higher integers encoding equality constrains. For multiple groups, this argument can be a list or array with each element/slice encoding such a matrix.

lowertri_y

Only used when type = "chol". Either "full" to estimate every element freely, "diag" to only include diagonal elements, or a matrix of the dimensions node x node with 0 encoding a fixed to zero element, 1 encoding a free to estimate element, and higher integers encoding equality constrains. For multiple groups, this argument can be a list or array with each element/slice encoding such a matrix.

delta_y

Only used when type = "ggm". Either "diag" or "zero" (not recommended), or a matrix of the dimensions node x node with 0 encoding a fixed to zero element, 1 encoding a free to estimate element, and higher integers encoding equality constrains. For multiple groups, this argument can be a list or array with each element/slice encoding such a matrix.

rho_y

Only used when type = "cor". Either "full" to estimate every element freely, "zero" to set all elements to zero, or a matrix of the dimensions node x node with 0 encoding a fixed to zero element, 1 encoding a free to estimate element, and higher integers encoding equality constrains. For multiple groups, this argument can be a list or array with each element/slice encoding such a matrix.

SD_y

Only used when type = "cor". Either "diag" or "zero", or a matrix of the dimensions node x node with 0 encoding a fixed to zero element, 1 encoding a free to estimate element, and higher integers encoding equality constrains. For multiple groups, this argument can be a list or array with each element/slice encoding such a matrix.

randomEffects

What to model for the random effects?

sigma_randomEffects

Only used when type = "cov". Either "full" to estimate every element freely, "diag" to only include diagonal elements, or a matrix of the dimensions node x node with 0 encoding a fixed to zero element, 1 encoding a free to estimate element, and higher integers encoding equality constrains. For multiple groups, this argument can be a list or array with each element/slice encoding such a matrix.

kappa_randomEffects

Only used when randomEffects = "prec". Either "full" to estimate every element freely, "diag" to only include diagonal elements, or a matrix of the dimensions node x node with 0 encoding a fixed to zero element, 1 encoding a free to estimate element, and higher integers encoding equality constrains. For multiple groups, this argument can be a list or array with each element/slice encoding such a matrix.

omega_randomEffects

Only used when randomEffects = "ggm". Either "full" to estimate every element freely, "zero" to set all elements to zero, or a matrix of the dimensions node x node with 0 encoding a fixed to zero element, 1 encoding a free to estimate element, and higher integers encoding equality constrains. For multiple groups, this argument can be a list or array with each element/slice encoding such a matrix.

lowertri_randomEffects

Only used when randomEffects = "chol". Either "full" to estimate every element freely, "diag" to only include diagonal elements, or a matrix of the dimensions node x node with 0 encoding a fixed to zero element, 1 encoding a free to estimate element, and higher integers encoding equality constrains. For multiple groups, this argument can be a list or array with each element/slice encoding such a matrix.

delta_randomEffects

Only used when randomEffects = "ggm". Either "diag" or "zero", or a matrix of the dimensions node x node with 0 encoding a fixed to zero element, 1 encoding a free to estimate element, and higher integers encoding equality constrains. For multiple groups, this argument can be a list or array with each element/slice encoding such a matrix.

rho_randomEffects

Only used when randomEffects = "cor". Either "full" to estimate every element freely, "zero" to set all elements to zero, or a matrix of the dimensions node x node with 0 encoding a fixed to zero element, 1 encoding a free to estimate element, and higher integers encoding equality constrains. For multiple groups, this argument can be a list or array with each element/slice encoding such a matrix.

SD_randomEffects

Only used when randomEffects = "cor". Either "diag" or "zero", or a matrix of the dimensions node x node with 0 encoding a fixed to zero element, 1 encoding a free to estimate element, and higher integers encoding equality constrains. For multiple groups, this argument can be a list or array with each element/slice encoding such a matrix.

vars

Variables to be included.

baseline_saturated

A logical indicating if the baseline and saturated model should be included. Mostly used internally and NOT Recommended to be used manually.

optimizer

The optimizer to be used. Can be one of "nlminb" (the default R nlminb function), "ucminf" (from the optimr package), and C++ based optimizers "cpp_L-BFGS-B", "cpp_BFGS", "cpp_CG", "cpp_SANN", and "cpp_Nelder-Mead". The C++ optimizers are faster but slightly less stable. Defaults to "nlminb".

estimator

The estimator to be used. Currently implemented are "ML" for maximum likelihood estimation or "FIML" for full-information maximum likelihood estimation.

sampleStats

An optional sample statistics object. Mostly used internally.

verbose

Logical, should progress be printed to the console?

bootstrap

Should the data be bootstrapped? If TRUE the data are resampled and a bootstrap sample is created. These must be aggregated using aggregate_bootstraps! Can be TRUE or FALSE. Can also be "nonparametric" (which sets boot_sub = 1 and boot_resample = TRUE) or "case" (which sets boot_sub = 0.75 and boot_resample = FALSE).

boot_sub

Proportion of cases to be subsampled (round(boot_sub * N)).

boot_resample

Logical, should the bootstrap be with replacement (TRUE) or without replacement (FALSE)

...

Arguments sent to meta_varcov

Value

An object of the class psychonetrics (psychonetrics-class)

Author(s)

Sacha Epskamp <[email protected]>

References

Jak, S., and Cheung, M. W. L. (2019). Meta-analytic structural equation modeling with moderating effects on SEM parameters. Psychological methods.


Print modification indices

Description

This function prints a list of modification indices (MIs)

Usage

MIs(x, all = FALSE, matrices, type = c("normal", "equal", "free"), top = 10, 
    verbose = TRUE, nonZero = FALSE)

Arguments

x

A psychonetrics model.

all

Logical, should all MIs be printed or only the highest?

matrices

Optional vector of matrices to include in the output.

type

String indicating which kind of modification index should be printed. ("mi" is the typical MI, "mi_free" is the modification index free from equality constrains across groups, and "mi_equal" is the modification index if the parameter is added constrained equal across all groups).

top

Number of MIs to include in output if all = FALSE

verbose

Logical, should messages be printed?

nonZero

Logical, should only MIs be printed of non-zero parameters? Useful to explore violations of group equality.

Value

Invisibly returns a relevant subset of the data frame containing all information on the parameters, or a list of such data frames if multiple types of MIs are requested.

Author(s)

Sacha Epskamp

Examples

# Load bfi data from psych package:
library("psychTools")
data(bfi)

# Also load dplyr for the pipe operator:
library("dplyr")

# Let's take the agreeableness items, and gender:
ConsData <- bfi %>% 
  select(A1:A5, gender) %>% 
  na.omit # Let's remove missingness (otherwise use Estimator = "FIML)

# Define variables:
vars <- names(ConsData)[1:5]

# Let's fit a full GGM:
mod <- ggm(ConsData, vars = vars, omega = "zero")

# Run model:
mod <- mod %>% runmodel

# Modification indices:
mod %>% MIs

Multi-level latent variable model family

Description

This family is the two-level random intercept variant of the lvm model family. It is mostly a special case of the dlvm1 family, with the addition of structural effects rather than temporal effects in the beta matrix.

Usage

ml_lnm(...)
ml_rnm(...)
ml_lrnm(...)
ml_lvm(data, lambda, clusters, within_latent = c("cov",
                   "chol", "prec", "ggm"), within_residual = c("cov",
                   "chol", "prec", "ggm"), between_latent = c("cov",
                   "chol", "prec", "ggm"), between_residual = c("cov",
                   "chol", "prec", "ggm"), beta_within = "zero",
                   beta_between = "zero", omega_zeta_within = "full",
                   delta_zeta_within = "full", kappa_zeta_within =
                   "full", sigma_zeta_within = "full",
                   lowertri_zeta_within = "full", omega_epsilon_within =
                   "zero", delta_epsilon_within = "diag",
                   kappa_epsilon_within = "diag", sigma_epsilon_within =
                   "diag", lowertri_epsilon_within = "diag",
                   omega_zeta_between = "full", delta_zeta_between =
                   "full", kappa_zeta_between = "full",
                   sigma_zeta_between = "full", lowertri_zeta_between =
                   "full", omega_epsilon_between = "zero",
                   delta_epsilon_between = "diag", kappa_epsilon_between
                   = "diag", sigma_epsilon_between = "diag",
                   lowertri_epsilon_between = "diag", nu, nu_eta,
                   identify = TRUE, identification = c("loadings",
                   "variance"), vars, latents, groups, equal = "none",
                   baseline_saturated = TRUE, estimator = c("FIML",
                   "MUML"), optimizer, storedata = FALSE, verbose =
                   FALSE, standardize = c("none", "z", "quantile"),
                   sampleStats, bootstrap = FALSE, boot_sub,
                   boot_resample)

Arguments

data

A data frame encoding the data used in the analysis. Must be a raw dataset.

lambda

A model matrix encoding the factor loading structure. Each row indicates an indicator and each column a latent. A 0 encodes a fixed to zero element, a 1 encoding a free to estimate element, and higher integers encoding equality constrains. For multiple groups, this argument can be a list or array with each element/slice encoding such a matrix. Could also be the result of simplestructure.

clusters

A string indicating the variable in the dataset that describes group membership.

within_latent

The type of within-person latent contemporaneous model to be used.

within_residual

The type of within-person residual model to be used.

between_latent

The type of between-person latent model to be used.

between_residual

The type of between-person residual model to be used.

beta_within

A model matrix encoding the within-cluster structural. A 0 encodes a fixed to zero element, a 1 encoding a free to estimate element, and higher integers encoding equality constrains. For multiple groups, this argument can be a list or array with each element/slice encoding such a matrix. Defaults to "zero".

beta_between

A model matrix encoding the between-cluster structural. A 0 encodes a fixed to zero element, a 1 encoding a free to estimate element, and higher integers encoding equality constrains. For multiple groups, this argument can be a list or array with each element/slice encoding such a matrix. Defaults to "zero".

omega_zeta_within

Only used when within_latent = "ggm". Can be "full", "zero", or a typical model matrix with 0s indicating parameters constrained to zero, 1s indicating free parameters, and higher integers indicating equality constrains. For multiple groups, this argument can be a list or array with each element/slice encoding such a matrix.

delta_zeta_within

Only used when within_latent = "ggm". Can be "diag", "zero" (not recommended), or a typical model matrix with 0s indicating parameters constrained to zero, 1s indicating free parameters, and higher integers indicating equality constrains. For multiple groups, this argument can be a list or array with each element/slice encoding such a matrix.

kappa_zeta_within

Only used when within_latent = "prec". Can be "full", "diag", or a typical model matrix with 0s indicating parameters constrained to zero, 1s indicating free parameters, and higher integers indicating equality constrains. For multiple groups, this argument can be a list or array with each element/slice encoding such a matrix.

sigma_zeta_within

Only used when within_latent = "cov". Can be "full", "diag", or a typical model matrix with 0s indicating parameters constrained to zero, 1s indicating free parameters, and higher integers indicating equality constrains. For multiple groups, this argument can be a list or array with each element/slice encoding such a matrix.

lowertri_zeta_within

Only used when within_latent = "chol". Can be "full", "diag", or a typical model matrix with 0s indicating parameters constrained to zero, 1s indicating free parameters, and higher integers indicating equality constrains. For multiple groups, this argument can be a list or array with each element/slice encoding such a matrix.

omega_epsilon_within

Only used when within_residual = "ggm". Can be "full", "zero", or a typical model matrix with 0s indicating parameters constrained to zero, 1s indicating free parameters, and higher integers indicating equality constrains. For multiple groups, this argument can be a list or array with each element/slice encoding such a matrix.

delta_epsilon_within

Only used when within_residual = "ggm". Can be "diag", "zero" (not recommended), or a typical model matrix with 0s indicating parameters constrained to zero, 1s indicating free parameters, and higher integers indicating equality constrains. For multiple groups, this argument can be a list or array with each element/slice encoding such a matrix.

kappa_epsilon_within

Only used when within_residual = "prec". Can be "full", "diag", or a typical model matrix with 0s indicating parameters constrained to zero, 1s indicating free parameters, and higher integers indicating equality constrains. For multiple groups, this argument can be a list or array with each element/slice encoding such a matrix.

sigma_epsilon_within

Only used when within_residual = "cov". Can be "full", "diag", or a typical model matrix with 0s indicating parameters constrained to zero, 1s indicating free parameters, and higher integers indicating equality constrains. For multiple groups, this argument can be a list or array with each element/slice encoding such a matrix.

lowertri_epsilon_within

Only used when within_residual = "chol". Can be "full", "diag", or a typical model matrix with 0s indicating parameters constrained to zero, 1s indicating free parameters, and higher integers indicating equality constrains. For multiple groups, this argument can be a list or array with each element/slice encoding such a matrix.

omega_zeta_between

Only used when between_latent = "ggm". Can be "full", "zero", or a typical model matrix with 0s indicating parameters constrained to zero, 1s indicating free parameters, and higher integers indicating equality constrains. For multiple groups, this argument can be a list or array with each element/slice encoding such a matrix.

delta_zeta_between

Only used when between_latent = "ggm". Can be "diag", "zero" (not recommended), or a typical model matrix with 0s indicating parameters constrained to zero, 1s indicating free parameters, and higher integers indicating equality constrains. For multiple groups, this argument can be a list or array with each element/slice encoding such a matrix.

kappa_zeta_between

Only used when between_latent = "prec". Can be "full", "diag", or a typical model matrix with 0s indicating parameters constrained to zero, 1s indicating free parameters, and higher integers indicating equality constrains. For multiple groups, this argument can be a list or array with each element/slice encoding such a matrix.

sigma_zeta_between

Only used when between_latent = "cov". Can be "full", "diag", or a typical model matrix with 0s indicating parameters constrained to zero, 1s indicating free parameters, and higher integers indicating equality constrains. For multiple groups, this argument can be a list or array with each element/slice encoding such a matrix.

lowertri_zeta_between

Only used when between_latent = "chol". Can be "full", "diag", or a typical model matrix with 0s indicating parameters constrained to zero, 1s indicating free parameters, and higher integers indicating equality constrains. For multiple groups, this argument can be a list or array with each element/slice encoding such a matrix.

omega_epsilon_between

Only used when between_residual = "ggm". Can be "full", "zero", or a typical model matrix with 0s indicating parameters constrained to zero, 1s indicating free parameters, and higher integers indicating equality constrains. For multiple groups, this argument can be a list or array with each element/slice encoding such a matrix.

delta_epsilon_between

Only used when between_residual = "ggm". Can be "diag", "zero" (not recommended), or a typical model matrix with 0s indicating parameters constrained to zero, 1s indicating free parameters, and higher integers indicating equality constrains. For multiple groups, this argument can be a list or array with each element/slice encoding such a matrix.

kappa_epsilon_between

Only used when between_residual = "prec". Can be "full", "diag", or a typical model matrix with 0s indicating parameters constrained to zero, 1s indicating free parameters, and higher integers indicating equality constrains. For multiple groups, this argument can be a list or array with each element/slice encoding such a matrix.

sigma_epsilon_between

Only used when between_residual = "cov". Can be "full", "diag", or a typical model matrix with 0s indicating parameters constrained to zero, 1s indicating free parameters, and higher integers indicating equality constrains. For multiple groups, this argument can be a list or array with each element/slice encoding such a matrix.

lowertri_epsilon_between

Only used when between_residual = "chol". Can be "full", "diag", or a typical model matrix with 0s indicating parameters constrained to zero, 1s indicating free parameters, and higher integers indicating equality constrains. For multiple groups, this argument can be a list or array with each element/slice encoding such a matrix.

nu

Optional vector encoding the intercepts of the observed variables. Set elements to 0 to indicate fixed to zero constrains, 1 to indicate free intercepts, and higher integers to indicate equality constrains. For multiple groups, this argument can be a list or array with each element/column encoding such a vector.

nu_eta

Optional vector encoding the intercepts of the latent variables. Set elements to 0 to indicate fixed to zero constrains, 1 to indicate free intercepts, and higher integers to indicate equality constrains. For multiple groups, this argument can be a list or array with each element/column encoding such a vector.

identify

Logical, should the model be automatically identified?

identification

Type of identification used. "loadings" to fix the first factor loadings to 1, and "variance" to fix the diagonal of the latent variable model matrix (sigma_zeta, lowertri_zeta, delta_zeta or kappa_zeta) to 1.

vars

An optional character vector with names of the variables used.

latents

An optional character vector with names of the latent variables.

groups

An optional string indicating the name of the group variable in data.

equal

A character vector indicating which matrices should be constrained equal across groups.

baseline_saturated

A logical indicating if the baseline and saturated model should be included. Mostly used internally and NOT Recommended to be used manually.

estimator

Estimator used. Currently only "FIML" is supported.

optimizer

The optimizer to be used. Usually either "nlminb" (with box constrains) or "ucminf" (ignoring box constrains), but any optimizer supported by optimr can be used.

storedata

Logical, should the raw data be stored? Needed for bootstrapping (see bootstrap).

verbose

Logical, should progress be printed to the console?

standardize

Which standardization method should be used? "none" (default) for no standardization, "z" for z-scores, and "quantile" for a non-parametric transformation to the quantiles of the marginal standard normal distribution.

sampleStats

An optional sample statistics object. Mostly used internally.

bootstrap

Should the data be bootstrapped? If TRUE the data are resampled and a bootstrap sample is created. These must be aggregated using aggregate_bootstraps! Can be TRUE or FALSE. Can also be "nonparametric" (which sets boot_sub = 1 and boot_resample = TRUE) or "case" (which sets boot_sub = 0.75 and boot_resample = FALSE).

boot_sub

Proportion of cases to be subsampled (round(boot_sub * N)).

boot_resample

Logical, should the bootstrap be with replacement (TRUE) or without replacement (FALSE)

...

Arguments sent to 'ml_lvm'

Value

An object of the class psychonetrics (psychonetrics-class)

Author(s)

Sacha Epskamp <[email protected]>


Multi-level Lag-1 dynamic latent variable model family of psychonetrics models for time-series data

Description

This function is a wrapper around dlvm1 that allows for specifying the model using a long format data and similar input as the mlVAR package. The ml_ts_lvgvar simply sets within_latent = "ggm" and between_latent = "ggm" by default. The ml_gvar and ml_var are simple wrappers with different named defaults for contemporaneous and between-person effects.

Usage

ml_tsdlvm1(data, beepvar, idvar, vars, groups, estimator = "FIML", 
  standardize = c("none", "z", "quantile"), ...)

ml_ts_lvgvar(...)

ml_gvar(..., contemporaneous = c("ggm", "cov", "chol", "prec"), 
        between = c("ggm", "cov", "chol", "prec"))
             
ml_var(..., contemporaneous = c("cov", "chol", "prec", "ggm"), 
        between = c("cov", "chol", "prec", "ggm"))

Arguments

data

The data to be used. Must be raw data in long format (each row indicates one person at one time point).

beepvar

Optional string indicating assessment beep per day. Adding this argument will cause non-consecutive beeps to be treated as missing!

idvar

String indicating the subject ID

vars

Vectors of variables to include in the analysis

groups

An optional string indicating the name of the group variable in data.

estimator

Estimator to be used. Must be "FIML".

standardize

Which standardization method should be used? "none" (default) for no standardization, "z" for z-scores, and "quantile" for a non-parametric transformation to the quantiles of the marginal standard normal distribution.

contemporaneous

The type of within-person latent contemporaneous model to be used.

between

The type of between-person latent model to be used.

...

Arguments sent to dlvm1

Author(s)

Sacha Epskamp <[email protected]>


Stepwise model search

Description

This function peforms stepwise model search to find an optimal model that (locally) minimzes some criterion (by default, the BIC).

Usage

modelsearch(x, criterion = "bic", matrices, prunealpha = 0.01,
                    addalpha = 0.01, verbose, ...)

Arguments

x

A psychonetrics model.

criterion

String indicating the criterion to minimize. Any criterion from fit can be used.

matrices

Vector of strings indicating which matrices should be searched. Will default to network structures and factor loadings.

prunealpha

Minimal alpha used to consider edges to be removed

addalpha

Maximum alpha used to consider edges to be added

verbose

Logical, should messages be printed?

...

Arguments sent to runmodel

Details

The full algorithm is as follows:

1. Evaluate all models in which an edge is removed that has p > prunealpha, or an edge is added that has a modification index with p < addalpha

2. If none of these models improve the criterion, return the previous model and stop the algorithm

3. Update the model to the model that improved the criterion the most

4. Evaluate all other considered models that improved the criterion

5. If none of these models improve the criterion, go to 1, else go to 3

Value

An object of the class psychonetrics (psychonetrics-class)

Author(s)

Sacha Epskamp

See Also

prune, stepup

Examples

# Load bfi data from psych package:
library("psychTools")
data(bfi)

# Also load dplyr for the pipe operator:
library("dplyr")

# Let's take the agreeableness items, and gender:
ConsData <- bfi %>% 
  select(A1:A5, gender) %>% 
  na.omit # Let's remove missingness (otherwise use Estimator = "FIML)

# Define variables:
vars <- names(ConsData)[1:5]

# Let's fit a full GGM:
mod <- ggm(ConsData, vars = vars)

# Run model:
mod <- mod %>% runmodel

# Model search
mod <- mod %>% prune(alpha= 0.01) %>% modelsearch

Print parameter estimates

Description

This function will print a list of parameters of the model

Usage

parameters(x)

Arguments

x

A psychonetrics model.

Value

Invisibly returns a data frame containing information on all parameters.

Author(s)

Sacha Epskamp

Examples

# Load bfi data from psych package:
library("psychTools")
data(bfi)

# Also load dplyr for the pipe operator:
library("dplyr")

# Let's take the agreeableness items, and gender:
ConsData <- bfi %>% 
  select(A1:A5, gender) %>% 
  na.omit # Let's remove missingness (otherwise use Estimator = "FIML)

# Define variables:
vars <- names(ConsData)[1:5]

# Let's fit a full GGM:
mod <- ggm(ConsData, vars = vars, omega = "zero")

# Run model:
mod <- mod %>% runmodel

# Parameter estimates:
mod %>% parameters

Set equality constrains across parameters

Description

This function can be used to set parameters equal

Usage

parequal(x, ..., inds = integer(0), verbose, log = TRUE,
                    runmodel = FALSE)

Arguments

x

A psychonetrics model.

...

Arguments sent to runmodel

inds

Parameter indices of parameters to be constrained equal

verbose

Logical, should messages be printed?

log

Logical, should the log be updated?

runmodel

Logical, should the model be updated?

Value

An object of the class psychonetrics (psychonetrics-class)

Author(s)

Sacha Epskamp


Partial pruning of multi-group models

Description

This function will search for a multi-group model with equality constrains on some but not all parameters. This is called partial pruning (Epskamp, Isvoranu, & Cheung, 2020; Haslbeck, 2020). The algorithm is as follows: 1. remove all parameters not significant at alpha in all groups (without equality constrains), 2. create a union model with all parameters included in any group included in all groups and constrained equal. 3. Stepwise free equality constrains of the parameter that features the largest sum of modification indices until BIC can no longer be improved. 4. Select and return (by default) the best model according to BIC (original model, pruned model, union model and partially pruned model).

Usage

partialprune(x, alpha = 0.01, matrices, verbose, combinefun = unionmodel, 
             return = c("best","partialprune","union_equal","prune"),
               criterion = "bic",  best = c("lowest","highest"), ...)

Arguments

x

A psychonetrics model.

alpha

Significance level to use.

matrices

Vector of strings indicating which matrices should be pruned. Will default to network structures.

verbose

Logical, should messages be printed?

combinefun

Function used to combine models of different groups.

return

What model to retur? "best" for best fitting model (according to BIC, "partialprune" for the partialpruned model, "union_equal" for the union model with equality constraints, and "prune" for the originally pruned model without equality constraints.)

best

Should the lowest or the highest index of criterion be used to select the final model?

criterion

What criterion to use for the model selection in the last step? Defaults to "bic" for BIC selection.

...

Arguments sent to prune.

Author(s)

Sacha Epskamp <[email protected]>

References

Epskamp, S., Isvoranu, A. M., & Cheung, M. (2020). Meta-analytic gaussian network aggregation. PsyArXiv preprint. DOI:10.31234/osf.io/236w8.

Haslbeck, J. (2020). Estimating Group Differences in Network Models using Moderation Analysis. PsyArXiv preprint. DOI:10.31234/osf.io/926pv.


Stepdown model search by pruning non-significant parameters.

Description

This function will (recursively) remove parameters that are not significant and refit the model.

Usage

prune(x, alpha = 0.01, adjust = c("none", "holm",
                    "hochberg", "hommel", "bonferroni", "BH", "BY",
                    "fdr"), matrices, runmodel = TRUE, recursive = FALSE,
                    verbose, log = TRUE, identify = TRUE, startreduce = 1,
                    limit = Inf, mode = c("tested","all"), ...)

Arguments

x

A psychonetrics model.

alpha

Significance level to use.

adjust

p-value adjustment method to use. See p.adjust.

matrices

Vector of strings indicating which matrices should be pruned. Will default to network structures.

runmodel

Logical, should the model be evaluated after pruning?

recursive

Logical, should the pruning process be repeated?

verbose

Logical, should messages be printed?

log

Logical, should the log be updated?

identify

Logical, should models be identified automatically?

startreduce

A numeric value indicating a factor with which the starting values should be reduced. Can be useful when encountering numeric problems.

limit

The maximum number of parameters to be pruned.

mode

Mode for adjusting for multiple comparisons. Should all parameters be considered as the total number of tests or only the tested parameters (parameters of interest)?

...

Arguments sent to runmodel

Value

An object of the class psychonetrics (psychonetrics-class)

Author(s)

Sacha Epskamp

See Also

stepup

Examples

# Load bfi data from psych package:
library("psychTools")
data(bfi)

# Also load dplyr for the pipe operator:
library("dplyr")

# Let's take the agreeableness items, and gender:
ConsData <- bfi %>% 
  select(A1:A5, gender) %>% 
  na.omit # Let's remove missingness (otherwise use Estimator = "FIML)

# Define variables:
vars <- names(ConsData)[1:5]

# Let's fit a full GGM:
mod <- ggm(ConsData, vars = vars, omega = "full")

# Run model:
mod <- mod %>% runmodel

# Prune model:
mod <- mod %>% prune(adjust = "fdr", recursive = FALSE)

Class "psychonetrics_bootstrap"

Description

Class for aggregated bootstrap results.

Objects from the Class

Objects can be created by calls of the form new("psychonetrics_bootstrap", ...).

Slots

model:

Object of class "character" ~~

submodel:

Object of class "character" ~~

parameters:

Object of class "data.frame" ~~

models:

Object of class "list" ~~

matrices:

Object of class "data.frame" ~~

fitmeasures:

Object of class "data.frame" ~~

distribution:

Object of class "character" ~~

verbose:

Object of class "logical" ~~

boot_sub:

Object of class "numeric" ~~

boot_resample:

Object of class "logical" ~~

n_fail:

Object of class "numeric" ~~

n_success:

Object of class "numeric" ~~

types:

Object of class "list" ~~

Methods

show

signature(object = "psychonetrics_bootstrap"): ...

Author(s)

Sacha Epskamp

Examples

showClass("psychonetrics_bootstrap")

Class "psychonetrics"

Description

A logbook entry in the psychonetrics logbook

Objects from the Class

Objects can be created by calls of the form new("psychonetrics_log", ...).

Slots

event:

Object of class "character" ~~

time:

Object of class "POSIXct" ~~

sessionInfo:

Object of class "sessionInfo" ~~

Methods

show

signature(object = "psychonetrics_log"): ...

Author(s)

Sacha Epskamp

Examples

showClass("psychonetrics_log")

Model updating functions

Description

These functions update a psychonetrics model. Typically they are not required.

Usage

addMIs(x, matrices = "all", type = c("normal", "free",
                    "equal"), verbose, analyticFisher = TRUE)

addSEs(x, verbose, approximate_SEs = FALSE)

addfit(x, verbose)

identify(x)

Arguments

x

A psychonetrics model.

matrices

Optional vector of matrices to include in MIs.

type

String indicating which modification indices should be updated.

verbose

Logical, should messages be printed?

analyticFisher

Logical indicating if an analytic Fisher information matrix should be used.

approximate_SEs

Logical, should standard errors be approximated? If true, an approximate matrix inverse of the Fischer information is used to obtain the standard errors.

Value

An object of the class psychonetrics (psychonetrics-class)

Author(s)

Sacha Epskamp


Class "psychonetrics"

Description

Main class for psychonetrics results.

Objects from the Class

Objects can be created by calls of the form new("psychonetrics", ...).

Slots

model:

Object of class "character" ~~

submodel:

Object of class "character" ~~

parameters:

Object of class "data.frame" ~~

matrices:

Object of class "data.frame" ~~

meanstructure:

Object of class "logical" ~~

computed:

Object of class "logical" ~~

sample:

Object of class "psychonetrics_samplestats" ~~

modelmatrices:

Object of class "list" ~~

log:

Object of class "psychonetrics_log" ~~

optim:

Object of class "list" ~~

fitmeasures:

Object of class "list" ~~

baseline_saturated:

Object of class "list" ~~

equal:

Object of class "character" ~~

objective:

Object of class "numeric" ~~

information:

Object of class "matrix" ~~

identification:

Object of class "character" ~~

optimizer:

Object of class "character" ~~

optim.args:

Object of class "list" ~~

estimator:

Object of class "character" ~~

distribution:

Object of class "character" ~~

extramatrices:

Object of class "list" ~~

rawts:

Object of class "logical" ~~

Drawts:

Object of class "list" ~~

types:

Object of class "list" ~~

cpp:

Object of class "logical" ~~

verbose:

Object of class "logical" ~~

Methods

resid

signature(object = "psychonetrics"): ...

residuals

signature(object = "psychonetrics"): ...

show

signature(object = "psychonetrics"): ...

Author(s)

Sacha Epskamp

Examples

showClass("psychonetrics")

Run a psychonetrics model

Description

This is the main function used to run a psychonetrics model.

Usage

runmodel(x, level = c("gradient", "fitfunction"), addfit =
                   TRUE, addMIs = TRUE, addSEs = TRUE, addInformation =
                   TRUE, log = TRUE, verbose, optim.control,
                   analyticFisher = TRUE, warn_improper = FALSE,
                   warn_gradient = TRUE, warn_bounds = TRUE,
                   return_improper = TRUE, bounded = TRUE,
                   approximate_SEs = FALSE)

Arguments

x

A psychonetrics model.

level

Level at which the model should be estimated. Defaults to "gradient" to indicate the analytic gradient should be used.

addfit

Logical, should fit measures be added?

addMIs

Logical, should modification indices be added?

addSEs

Logical, should standard errors be added?

addInformation

Logical, should the Fisher information be added?

log

Logical, should the log be updated?

verbose

Logical, should messages be printed?

optim.control

A list with options for optimr

analyticFisher

Logical, should the analytic Fisher information be used? If FALSE, numeric information is used instead.

return_improper

Should a result in which improper computation was used be return? Improper computation can mean that a pseudoinverse of small spectral shift was used in computing the inverse of a matrix.

warn_improper

Logical. Should a warning be given when at some point in the estimation a pseudoinverse was used?

warn_gradient

Logical. Should a warning be given when the average absolute gradient is > 1?

bounded

Logical. Should bounded estimation be used (e.g., variances should be positive)?

approximate_SEs

Logical, should standard errors be approximated? If true, an approximate matrix inverse of the Fischer information is used to obtain the standard errors.

warn_bounds

Should a warning be given when a parameter is estimated near its bounds?

Value

An object of the class psychonetrics (psychonetrics-class)

Author(s)

Sacha Epskamp

Examples

# Load bfi data from psych package:
library("psychTools")
data(bfi)

# Also load dplyr for the pipe operator:
library("dplyr")

# Let's take the agreeableness items, and gender:
ConsData <- bfi %>% 
  select(A1:A5, gender) %>% 
  na.omit # Let's remove missingness (otherwise use Estimator = "FIML)

# Define variables:
vars <- names(ConsData)[1:5]

# Let's fit a full GGM:
mod <- ggm(ConsData, vars = vars, omega = "full")

# Run model:
mod <- mod %>% runmodel

Convenience functions

Description

These functions can be used to change some estimator options.

Usage

setestimator(x, estimator)

setoptimizer(x, optimizer = c("default", "nlminb", "ucminf",
                 "cpp_L-BFGS-B", "cpp_BFGS", "cpp_CG", "cpp_SANN",
                 "cpp_Nelder-Mead"), optim.args)


usecpp(x, use = TRUE)

Arguments

x

A psychonetrics model.

estimator

A string indicating the estimator to be used

optimizer

The optimizer to be used. Can be one of "nlminb" (the default R nlminb function), "ucminf" (from the optimr package), and C++ based optimizers "cpp_L-BFGS-B", "cpp_BFGS", "cpp_CG", "cpp_SANN", and "cpp_Nelder-Mead". The C++ optimizers are faster but slightly less stable. Defaults to "nlminb".

use

Logical indicating if C++ should be used (currently only used in FIML)

optim.args

List of arguments to sent to the optimizer.

Details

The default optimizer is nlminb with the following arguments:

  • eval.max=20000L

  • iter.max=10000L

  • trace=0L

  • abs.tol=sqrt(.Machine$double.eps)

  • rel.tol=sqrt(.Machine$double.eps)

  • step.min=1.0

  • step.max=1.0

  • x.tol=1.5e-8

  • xf.tol=2.2e-14

Value

An object of the class psychonetrics (psychonetrics-class)

Author(s)

Sacha Epskamp


Should messages of computation progress be printed?

Description

This function controls if messages should be printed for a psychonetrics model.

Usage

setverbose(x, verbose = TRUE)

Arguments

x

A psychonetrics model.

verbose

Logical indicating if verbose should be enabled

Value

An object of the class psychonetrics (psychonetrics-class)

Author(s)

Sacha Epskamp


Generate factor loadings matrix with simple structure

Description

This function generates the input for lambda arguments in latent variable models using a simple structure. The input is a vector with an element for each variable indicating the factor the variable loads on.

Usage

simplestructure(x)

Arguments

x

A vector indicating which factor each indicator loads on.

Author(s)

Sacha Epskamp <[email protected]>


Star Wars dataset

Description

This questionaire was constructed by Carolin Katzera, Charlotte Tanis, Esther Niehoff, Myrthe Veenman, and Jason Nak as part of an assignment for a course on confirmatory factor analysis (http://sachaepskamp.com/SEM2018). They also collected the data among fellow psychology students as well as through social media.

Usage

data("StarWars")

Format

A data frame with 271 observations on the following 13 variables.

Q1

I am a huge Star Wars fan! (star what?)

Q2

I would trust this person with my democracy <picture of Jar Jar Binks>

Q3

I enjoyed the story of Anakin's early life

Q4

The special effects in this scene are awful <video of the Battle of Geonosis>

Q5

I would trust this person with my life <picture of Han Solo>

Q6

I found Darth Vader'ss big reveal in "Empire" one of the greatest moments in movie history

Q7

The special effects in this scene are amazing <video of the Death Star explosion>

Q8

If possible, I would definitely buy this droid <picture of BB-8>

Q9

The story in the Star Wars sequels is an improvement to the previous movies

Q10

The special effects in this scene are marvellous <video of the Starkiller Base firing>

Q11

What is your gender?

Q12

How old are you?

Q13

Have you seen any of the Star Wars movies?

Details

The questionaire is online at https://github.com/SachaEpskamp/SEM-code-examples/blob/master/CFA_fit_examples/StarWars_questionaire.pdf. The authors of the questionaire defined a measurement model before collecting data: Q2 - Q4 are expected to load on a "prequel" factor, Q5 - Q7 are expected to load in a "originals" factor, and Q8 - Q10 are expected to load on a "sequal" factor. Finally, Q1 is expected to load on all three.

Source

https://github.com/SachaEpskamp/SEM-code-examples/blob/master/CFA_fit_examples

Examples

data(StarWars)

Stepup model search along modification indices

Description

This function automatically peforms step-up search by adding the parameter with the largest modification index until some criterion is reached or no modification indices are significant at alpha.

Usage

stepup(x, alpha = 0.01, criterion = "bic", matrices, mi =
                    c("mi", "mi_free", "mi_equal"), greedyadjust =
                    c("bonferroni", "none", "holm", "hochberg", "hommel",
                    "fdr", "BH", "BY"), stopif, greedy = FALSE, verbose,
                    checkinformation = TRUE, singularinformation =
                    c("tryfix", "skip", "continue", "stop"), startEPC =
                    TRUE, ...)

Arguments

x

A psychonetrics model.

alpha

Significance level to use.

criterion

String indicating the criterion to minimize. Any criterion from fit can be used.

matrices

Vector of strings indicating which matrices should be searched. Will default to network structures and factor loadings.

mi

String indicating which kind of modification index should be used ("mi" is the typical MI, "mi_free" is the modification index free from equality constrains across groups, and "mi_equal" is the modification index if the parameter is added constrained equal across all groups).

greedyadjust

String indicating which p-value adjustment should be used in greedy start. Any method from p.adjust can be used.

stopif

An R expression, using objects from fit, which will break stepup search if it evaluates to TRUE. For example, stopif = rmsea < 0.05 will lead to search to stop if rmsea is below 0.05.

greedy

Logical, should a greedy start be used? If TRUE, the first step adds any parameter that is significant (after adjustement)

verbose

Logical, should messages be printed?

checkinformation

Logical, should the Fisher information be checked for potentially non-identified models?

singularinformation

String indicating how to proceed if the information matrix is singular. "tryfix" will adjust starting values to try to fix the proble, "skip" will lead to the algorithm to skip the current parameter, "continue" will ignore the situation, and "stop" will break the algorithm and return a list with the last two models.

startEPC

Logical, should the starting value be set at the expected parameter change?

...

Arguments sent to runmodel

Value

An object of the class psychonetrics (psychonetrics-class)

Author(s)

Sacha Epskamp

See Also

prune

Examples

# Load bfi data from psych package:
library("psychTools")
data(bfi)

# Also load dplyr for the pipe operator:
library("dplyr")

# Let's take the agreeableness items, and gender:
ConsData <- bfi %>%
  select(A1:A5, gender) %>%
  na.omit # Let's remove missingness (otherwise use Estimator = "FIML)

# Define variables:
vars <- names(ConsData)[1:5]

# Let's fit a full GGM:
mod <- ggm(ConsData, vars = vars, omega = "full")

# Run model:
mod <- mod %>%runmodel %>%prune(alpha = 0.05)

# Remove an edge (example):
mod <- mod %>%fixpar("omega",1,2) %>%runmodel

# Stepup search
mod <- mod %>%stepup(alpha = 0.05)

Transform between model types

Description

This function allows to transform a model variance–covariance structure from one type to another. Its main uses are to (1) use a Cholesky decomposition to estimate a saturated covariance matrix or GGM, and (2) to transform between conditional (ggm) and marginal associations (cov).

Usage

transmod(x, ..., verbose, keep_computed = FALSE, log = TRUE,
         identify = TRUE)

Arguments

x

A psychonetrics model

...

Named arguments with the new types to use (e.g., between = "ggm" or y = "cov")

verbose

Logical, should messages be printed?

keep_computed

Logical, should the model be stated to be uncomputed adter the transformation? In general, a model does not need to be re-computed as transformed parameters should be at the maximum likelihood estimate.

log

Logical, should a logbook entry be made?

identify

Logical, should the model be identified after transforming?

Details

Transformations are only possible if the model is diagonal (e.g., no partial correlations) or saturated (e.g., all covariances included).

Author(s)

Sacha Epskamp

Examples

# Load bfi data from psych package:
library("psychTools")
data(bfi)

# Also load dplyr for the pipe operator:
library("dplyr")

# Let's take the agreeableness items, and gender:
ConsData <- bfi %>% 
  select(A1:A5, gender) %>% 
  na.omit # Let's remove missingness (otherwise use Estimator = "FIML)

# Define variables:
vars <- names(ConsData)[1:5]

# Model with Cholesky decompositon:
mod <- varcov(ConsData, vars = vars, type = "chol")

# Run model:
mod <- mod %>% runmodel

# Transform to GGM:
mod_trans <- transmod(mod, type = "ggm") %>% runmodel
# Note: runmodel often not needed

# Obtain thresholded GGM:
getmatrix(mod_trans, "omega", threshold = TRUE)

Lag-1 dynamic latent variable model family of psychonetrics models for time-series data

Description

This is the family of models that models a dynamic factor model on time-series. There are two covariance structures that can be modeled in different ways: contemporaneous for the contemporaneous model and residual for the residual model. These can be set to "cov" for covariances, "prec" for a precision matrix, "ggm" for a Gaussian graphical model and "chol" for a Cholesky decomposition. The ts_lvgvar wrapper function sets contemporaneous = "ggm" for the graphical VAR model.

Usage

tsdlvm1(data, lambda, contemporaneous = c("cov", "chol",
                   "prec", "ggm"), residual = c("cov", "chol", "prec",
                   "ggm"), beta = "full", omega_zeta = "full", delta_zeta
                   = "diag", kappa_zeta = "full", sigma_zeta = "full",
                   lowertri_zeta = "full", omega_epsilon = "zero",
                   delta_epsilon = "diag", kappa_epsilon = "diag",
                   sigma_epsilon = "diag", lowertri_epsilon = "diag", nu,
                   mu_eta, identify = TRUE, identification =
                   c("loadings", "variance"), latents, beepvar, dayvar,
                   idvar, vars, groups, covs, means, nobs, missing =
                   "listwise", equal = "none", baseline_saturated = TRUE,
                   estimator = "ML", optimizer, storedata = FALSE,
                   sampleStats, covtype = c("choose", "ML", "UB"),
                   centerWithin = FALSE, standardize = c("none", "z",
                   "quantile"), verbose = FALSE, bootstrap = FALSE,
                   boot_sub, boot_resample)

ts_lvgvar(...)

Arguments

data

A data frame encoding the data used in the analysis. Can be missing if covs and nobs are supplied.

lambda

A model matrix encoding the factor loading structure. Each row indicates an indicator and each column a latent. A 0 encodes a fixed to zero element, a 1 encoding a free to estimate element, and higher integers encoding equality constrains. For multiple groups, this argument can be a list or array with each element/slice encoding such a matrix.

contemporaneous

The type of contemporaneous model used. See description.

residual

The type of residual model used. See description.

beta

A model matrix encoding the temporal relationships (transpose of temporal network) between latent variables. A 0 encodes a fixed to zero element, a 1 encoding a free to estimate element, and higher integers encoding equality constrains. For multiple groups, this argument can be a list or array with each element/slice encoding such a matrix. Can also be "full" for a full temporal network or "zero" for an empty temporal network.

omega_zeta

Only used when contemporaneous = "ggm". Either "full" to estimate every element freely, "zero" to set all elements to zero, or a matrix of the dimensions node x node with 0 encoding a fixed to zero element, 1 encoding a free to estimate element, and higher integers encoding equality constrains. For multiple groups, this argument can be a list or array with each element/slice encoding such a matrix.

delta_zeta

Only used when contemporaneous = "ggm". Either "diag" or "zero" (not recommended), or a matrix of the dimensions node x node with 0 encoding a fixed to zero element, 1 encoding a free to estimate element, and higher integers encoding equality constrains. For multiple groups, this argument can be a list or array with each element/slice encoding such a matrix.

kappa_zeta

Only used when contemporaneous = "prec". Either "full" to estimate every element freely, "diag" to only include diagonal elements, or a matrix of the dimensions node x node with 0 encoding a fixed to zero element, 1 encoding a free to estimate element, and higher integers encoding equality constrains. For multiple groups, this argument can be a list or array with each element/slice encoding such a matrix.

sigma_zeta

Only used when contemporaneous = "cov". Either "full" to estimate every element freely, "diag" to only include diagonal elements, or a matrix of the dimensions node x node with 0 encoding a fixed to zero element, 1 encoding a free to estimate element, and higher integers encoding equality constrains. For multiple groups, this argument can be a list or array with each element/slice encoding such a matrix.

lowertri_zeta

Only used when contemporaneous = "chol". Either "full" to estimate every element freely, "diag" to only include diagonal elements, or a matrix of the dimensions node x node with 0 encoding a fixed to zero element, 1 encoding a free to estimate element, and higher integers encoding equality constrains. For multiple groups, this argument can be a list or array with each element/slice encoding such a matrix.

omega_epsilon

Only used when residual = "ggm". Either "full" to estimate every element freely, "zero" to set all elements to zero, or a matrix of the dimensions node x node with 0 encoding a fixed to zero element, 1 encoding a free to estimate element, and higher integers encoding equality constrains. For multiple groups, this argument can be a list or array with each element/slice encoding such a matrix.

delta_epsilon

Only used when residual = "ggm". Either "diag" or "zero" (not recommended), or a matrix of the dimensions node x node with 0 encoding a fixed to zero element, 1 encoding a free to estimate element, and higher integers encoding equality constrains. For multiple groups, this argument can be a list or array with each element/slice encoding such a matrix.

kappa_epsilon

Only used when residual = "prec". Either "full" to estimate every element freely, "diag" to only include diagonal elements, or a matrix of the dimensions node x node with 0 encoding a fixed to zero element, 1 encoding a free to estimate element, and higher integers encoding equality constrains. For multiple groups, this argument can be a list or array with each element/slice encoding such a matrix.

sigma_epsilon

Only used when residual = "cov". Either "full" to estimate every element freely, "diag" to only include diagonal elements, or a matrix of the dimensions node x node with 0 encoding a fixed to zero element, 1 encoding a free to estimate element, and higher integers encoding equality constrains. For multiple groups, this argument can be a list or array with each element/slice encoding such a matrix.

lowertri_epsilon

Only used when residual = "chol". Either "full" to estimate every element freely, "diag" to only include diagonal elements, or a matrix of the dimensions node x node with 0 encoding a fixed to zero element, 1 encoding a free to estimate element, and higher integers encoding equality constrains. For multiple groups, this argument can be a list or array with each element/slice encoding such a matrix.

nu

Optional vector encoding the intercepts of the observed variables. Set elements to 0 to indicate fixed to zero constrains, 1 to indicate free intercepts, and higher integers to indicate equality constrains. For multiple groups, this argument can be a list or array with each element/column encoding such a vector.

mu_eta

Optional vector encoding the means of the latent variables. Set elements to 0 to indicate fixed to zero constrains, 1 to indicate free intercepts, and higher integers to indicate equality constrains. For multiple groups, this argument can be a list or array with each element/column encoding such a vector.

identify

Logical, should the model be automatically identified?

identification

Type of identification used. "loadings" to fix the first factor loadings to 1, and "variance" to fix the diagonal of the latent variable model matrix (sigma_zeta, lowertri_zeta, delta_zeta or kappa_zeta) to 1.

latents

An optional character vector with names of the latent variables.

beepvar

Optional string indicating assessment beep per day. Adding this argument will cause non-consecutive beeps to be treated as missing!

dayvar

Optional string indicating assessment day. Adding this argument makes sure that the first measurement of a day is not regressed on the last measurement of the previous day. IMPORTANT: only add this if the data has multiple observations per day.

idvar

Optional string indicating the subject ID

vars

An optional character vector encoding the variables used in the analyis. Must equal names of the dataset in data.

groups

An optional string indicating the name of the group variable in data.

covs

A sample variance–covariance matrix, or a list/array of such matrices for multiple groups. Make sure covtype argument is set correctly to the type of covariances used.

means

A vector of sample means, or a list/matrix containing such vectors for multiple groups.

nobs

The number of observations used in covs and means, or a vector of such numbers of observations for multiple groups.

missing

How should missingness be handled in computing the sample covariances and number of observations when data is used. Can be "listwise" for listwise deletion, or "pairwise" for pairwise deletion.

equal

A character vector indicating which matrices should be constrained equal across groups.

baseline_saturated

A logical indicating if the baseline and saturated model should be included. Mostly used internally and NOT Recommended to be used manually.

estimator

The estimator to be used. Currently implemented are "ML" for maximum likelihood estimation, "FIML" for full-information maximum likelihood estimation, "ULS" for unweighted least squares estimation, "WLS" for weighted least squares estimation, and "DWLS" for diagonally weighted least squares estimation.

optimizer

The optimizer to be used. Can be one of "nlminb" (the default R nlminb function), "ucminf" (from the optimr package), and C++ based optimizers "cpp_L-BFGS-B", "cpp_BFGS", "cpp_CG", "cpp_SANN", and "cpp_Nelder-Mead". The C++ optimizers are faster but slightly less stable. Defaults to "nlminb".

storedata

Logical, should the raw data be stored? Needed for bootstrapping (see bootstrap).

standardize

Which standardization method should be used? "none" (default) for no standardization, "z" for z-scores, and "quantile" for a non-parametric transformation to the quantiles of the marginal standard normal distribution.

sampleStats

An optional sample statistics object. Mostly used internally.

centerWithin

Logical, should data be within-person centered?

covtype

If 'covs' is used, this is the type of covariance (maximum likelihood or unbiased) the input covariance matrix represents. Set to "ML" for maximum likelihood estimates (denominator n) and "UB" to unbiased estimates (denominator n-1). The default will try to find the type used, by investigating which is most likely to result from integer valued datasets.

verbose

Logical, should messages be printed?

bootstrap

Should the data be bootstrapped? If TRUE the data are resampled and a bootstrap sample is created. These must be aggregated using aggregate_bootstraps! Can be TRUE or FALSE. Can also be "nonparametric" (which sets boot_sub = 1 and boot_resample = TRUE) or "case" (which sets boot_sub = 0.75 and boot_resample = FALSE).

boot_sub

Proportion of cases to be subsampled (round(boot_sub * N)).

boot_resample

Logical, should the bootstrap be with replacement (TRUE) or without replacement (FALSE)

...

Arguments sent to tsdlvm1

Value

An object of the class psychonetrics (psychonetrics-class)

Author(s)

Sacha Epskamp

Examples

# Note: this example is wrapped in a dontrun environment because the data is not 
# available locally.
## Not run: 
# Obtain the data from:
#
# Epskamp, S., van Borkulo, C. D., van der Veen, D. C., Servaas, M. N., Isvoranu, A. M., 
# Riese, H., & Cramer, A. O. (2018). Personalized network modeling in psychopathology: 
# The importance of contemporaneous and temporal connections. Clinical Psychological 
# Science, 6(3), 416-427.
# 
# Available here: https://osf.io/c8wjz/
tsdata <- read.csv("Supplementary2_data.csv")

# Encode time variable in a way R understands:
tsdata$time <- as.POSIXct(tsdata$time, tz = "Europe/Amsterdam")

# Extract days:
tsdata$Day <- as.Date(tsdata$time, tz = "Europe/Amsterdam")

# Variables to use:
vars <- c("relaxed", "sad", "nervous", "concentration", "tired", "rumination", 
          "bodily.discomfort")

# Create lambda matrix (in this case: one factor):
Lambda <- matrix(1,7,1)

# Estimate dynamical factor model:
model <- tsdlvm1(
  tsdata, 
  lambda = Lambda,
  vars = vars, 
  dayvar = "Day",
  estimator = "FIML"
)

# Run model:
model <- model %>% runmodel

# Look at fit:
model %>% print
model %>% fit # Pretty bad fit

## End(Not run)

Unify models across groups

Description

The unionmodel will add all parameters to all groups that are free in at least one group, and the intersectionmodel will constrain all parameters across groups to zero unless they are free to estimate in all groups.

Usage

unionmodel(x, runmodel = FALSE, verbose, log = TRUE, identify =
                    TRUE, matrices, ...)

intersectionmodel(x, runmodel = FALSE, verbose, log = TRUE, identify =
                    TRUE, matrices, ...)

Arguments

x

A psychonetrics model.

runmodel

Logical, should the model be updated?

verbose

Logical, should messages be printed?

log

Logical, should the log be updated?

identify

Logical, should the model be identified?

matrices

Which matrices should be used to form the union/intersection model?

...

Arguments sent to runmodel

Value

An object of the class psychonetrics (psychonetrics-class)

Author(s)

Sacha Epskamp


Lag-1 vector autoregression family of psychonetrics models

Description

This is the family of models that models time-series data using a lag-1 vector autoregressive model (VAR; Epskamp,Waldorp, Mottus, Borsboom, 2018). The model is fitted to the Toeplitz matrix, but unlike typical SEM software the block of covariances of the lagged variables is not used in estimating the temporal and contemporaneous relationships (the block is modeled completely separately using a cholesky decomposition, and does not enter the model elsewise). The contemporaneous argument can be used to define what contemporaneous model is used: contemporaneous = "cov" (default) models a variance-covariance matrix, contemporaneous = "chol" models a Cholesky decomposition, contemporaneous = "prec" models a precision matrix, and contemporaneous = "ggm" (alias: gvar()) models a Gaussian graphical model, also then known as a graphical VAR model.

Usage

var1(data, contemporaneous = c("cov", "chol", "prec",
                   "ggm"), beta = "full", omega_zeta = "full", delta_zeta
                   = "full", kappa_zeta = "full", sigma_zeta = "full",
                   lowertri_zeta = "full", mu, beepvar, dayvar, idvar,
                   vars, groups, covs, means, nobs, missing = "listwise",
                   equal = "none", baseline_saturated = TRUE, estimator =
                   "ML", optimizer, storedata = FALSE, covtype =
                   c("choose", "ML", "UB"), standardize = c("none", "z",
                   "quantile"), sampleStats, verbose = FALSE, bootstrap =
                   FALSE, boot_sub, boot_resample)

gvar(...)

Arguments

data

A data frame encoding the data used in the analysis. Can be missing if covs and nobs are supplied.

contemporaneous

The type of contemporaneous model used. See description.

beta

A model matrix encoding the temporal relationships (transpose of temporal network). A 0 encodes a fixed to zero element, a 1 encoding a free to estimate element, and higher integers encoding equality constrains. For multiple groups, this argument can be a list or array with each element/slice encoding such a matrix. Can also be "full" for a full temporal network or "zero" for an empty temporal network.

omega_zeta

Only used when contemporaneous = "ggm". Either "full" to estimate every element freely, "zero" to set all elements to zero, or a matrix of the dimensions node x node with 0 encoding a fixed to zero element, 1 encoding a free to estimate element, and higher integers encoding equality constrains. For multiple groups, this argument can be a list or array with each element/slice encoding such a matrix.

delta_zeta

Only used when contemporaneous = "ggm". Either "diag" to estimate all scalings or "zero" (not recommended) to set all elements to zero, or a matrix of the dimensions node x node with 0 encoding a fixed to zero element, 1 encoding a free to estimate element, and higher integers encoding equality constrains. For multiple groups, this argument can be a list or array with each element/slice encoding such a matrix.

kappa_zeta

Only used when contemporaneous = "prec". Either "full" to estimate every element freely, "diag" to only include diagonal elements, or a matrix of the dimensions node x node with 0 encoding a fixed to zero element, 1 encoding a free to estimate element, and higher integers encoding equality constrains. For multiple groups, this argument can be a list or array with each element/slice encoding such a matrix.

sigma_zeta

Only used when contemporaneous = "cov". Either "full" to estimate every element freely, "diag" to only include diagonal elements, or a matrix of the dimensions node x node with 0 encoding a fixed to zero element, 1 encoding a free to estimate element, and higher integers encoding equality constrains. For multiple groups, this argument can be a list or array with each element/slice encoding such a matrix.

lowertri_zeta

Only used when contemporaneous = "chol". Either "full" to estimate every element freely, "diag" to only include diagonal elements, or a matrix of the dimensions node x node with 0 encoding a fixed to zero element, 1 encoding a free to estimate element, and higher integers encoding equality constrains. For multiple groups, this argument can be a list or array with each element/slice encoding such a matrix.

mu

Optional vector encoding the mean structure. Set elements to 0 to indicate fixed to zero constrains, 1 to indicate free means, and higher integers to indicate equality constrains. For multiple groups, this argument can be a list or array with each element/column encoding such a vector.

beepvar

Optional string indicating assessment beep per day. Adding this argument will cause non-consecutive beeps to be treated as missing!

dayvar

Optional string indicating assessment day. Adding this argument makes sure that the first measurement of a day is not regressed on the last measurement of the previous day. IMPORTANT: only add this if the data has multiple observations per day.

idvar

Optional string indicating the subject ID

vars

An optional character vector encoding the variables used in the analyis. Must equal names of the dataset in data.

groups

An optional string indicating the name of the group variable in data.

covs

A sample variance–covariance matrix, or a list/array of such matrices for multiple groups. Make sure covtype argument is set correctly to the type of covariances used.

means

A vector of sample means, or a list/matrix containing such vectors for multiple groups.

nobs

The number of observations used in covs and means, or a vector of such numbers of observations for multiple groups.

missing

How should missingness be handled in computing the sample covariances and number of observations when data is used. Can be "listwise" for listwise deletion, or "pairwise" for pairwise deletion.

equal

A character vector indicating which matrices should be constrained equal across groups.

baseline_saturated

A logical indicating if the baseline and saturated model should be included. Mostly used internally and NOT Recommended to be used manually.

estimator

The estimator to be used. Currently implemented are "ML" for maximum likelihood estimation, "FIML" for full-information maximum likelihood estimation, "ULS" for unweighted least squares estimation, "WLS" for weighted least squares estimation, and "DWLS" for diagonally weighted least squares estimation.

optimizer

The optimizer to be used. Can be one of "nlminb" (the default R nlminb function), "ucminf" (from the optimr package), and C++ based optimizers "cpp_L-BFGS-B", "cpp_BFGS", "cpp_CG", "cpp_SANN", and "cpp_Nelder-Mead". The C++ optimizers are faster but slightly less stable. Defaults to "nlminb".

storedata

Logical, should the raw data be stored? Needed for bootstrapping (see bootstrap).

standardize

Which standardization method should be used? "none" (default) for no standardization, "z" for z-scores, and "quantile" for a non-parametric transformation to the quantiles of the marginal standard normal distribution.

sampleStats

An optional sample statistics object. Mostly used internally.

covtype

If 'covs' is used, this is the type of covariance (maximum likelihood or unbiased) the input covariance matrix represents. Set to "ML" for maximum likelihood estimates (denominator n) and "UB" to unbiased estimates (denominator n-1). The default will try to find the type used, by investigating which is most likely to result from integer valued datasets.

verbose

Logical, should messages be printed?

bootstrap

Should the data be bootstrapped? If TRUE the data are resampled and a bootstrap sample is created. These must be aggregated using aggregate_bootstraps! Can be TRUE or FALSE. Can also be "nonparametric" (which sets boot_sub = 1 and boot_resample = TRUE) or "case" (which sets boot_sub = 0.75 and boot_resample = FALSE).

boot_sub

Proportion of cases to be subsampled (round(boot_sub * N)).

boot_resample

Logical, should the bootstrap be with replacement (TRUE) or without replacement (FALSE)

...

Arguments sent to var1

Details

This will be updated in a later version.

Value

An object of the class psychonetrics

Author(s)

Sacha Epskamp

References

Epskamp, S., Waldorp, L. J., Mottus, R., & Borsboom, D. (2018). The Gaussian graphical model in cross-sectional and time-series data. Multivariate Behavioral Research, 53(4), 453-480.

See Also

lvm, varcov, dlvm1

Examples

library("dplyr")
library("graphicalVAR")

beta <- matrix(c(
  0,0.5,
  0.5,0
),2,2,byrow=TRUE)
kappa <- diag(2)
simData <- graphicalVARsim(50, beta, kappa)

# Form model:
model <- gvar(simData)

# Evaluate model:
model <- model %>% runmodel

# Parameter estimates:
model %>% parameters

# Plot the CIs:
CIplot(model,  "beta")

# Note: this example is wrapped in a dontrun environment because the data is not 
# available locally.
## Not run: 
# Longer example:
#
# Obtain the data from:
#
# Epskamp, S., van Borkulo, C. D., van der Veen, D. C., Servaas, M. N., Isvoranu, A. M., 
# Riese, H., & Cramer, A. O. (2018). Personalized network modeling in psychopathology: 
# The importance of contemporaneous and temporal connections. Clinical Psychological 
# Science, 6(3), 416-427.
# 
# Available here: https://osf.io/c8wjz/

tsdata <- read.csv("Supplementary2_data.csv")

# Encode time variable in a way R understands:
tsdata$time <- as.POSIXct(tsdata$time, tz = "Europe/Amsterdam")

# Extract days:
tsdata$Day <- as.Date(tsdata$time, tz = "Europe/Amsterdam")

# Variables to use:
vars <- c("relaxed", "sad", "nervous", "concentration", "tired", "rumination", 
          "bodily.discomfort")

# Estimate, prune with FDR, and perform stepup search:
model_FDRprune <- gvar(
  tsdata, 
  vars = vars, 
  dayvar = "Day",
  estimator = "FIML"
  ) %>% 
  runmodel %>% 
  prune(adjust = "fdr", recursive = FALSE) %>% 
  stepup(criterion = "bic")

# Estimate with greedy stepup search:
model_stepup <- gvar(
  tsdata, 
  vars = vars, 
  dayvar = "Day",
  estimator = "FIML",
  omega_zeta = "zero",
  beta = "zero"
) %>% 
  runmodel %>% 
  stepup(greedy = TRUE, greedyadjust = "bonferroni", criterion = "bic")

# Compare models:
compare(
  FDRprune = model_FDRprune,
  stepup = model_stepup
)
# Very similar but not identical. Stepup is prefered here according to AIC and BIC

# Stepup results:
temporal <- getmatrix(model_stepup, "PDC") # PDC = Partial Directed Correlations
contemporaneous <- getmatrix(model_stepup, "omega_zeta")

# Average layout:
library("qgraph")
L <- averageLayout(temporal, contemporaneous)

# Labels:
labs <- gsub("\\.","\n",vars)

# Plot:
layout(t(1:2))
qgraph(temporal, layout = L, theme = "colorblind", directed=TRUE, diag=TRUE,
       title = "Temporal", vsize = 12, mar = rep(6,4), asize = 5,
       labels = labs)
qgraph(contemporaneous, layout = L, theme = "colorblind", 
       title = "Contemporaneous", vsize = 12, mar = rep(6,4), asize = 5,
       labels = labs)

## End(Not run)

Variance-covariance family of psychonetrics models

Description

This is the family of models that models only a variance-covariance matrix with mean structure. The type argument can be used to define what model is used: type = "cov" (default) models a variance-covariance matrix directly, type = "chol" (alias: cholesky()) models a Cholesky decomposition, type = "prec" (alias: precision()) models a precision matrix, type = "ggm" (alias: ggm()) models a Gaussian graphical model (Epskamp, Rhemtulla and Borsboom, 2017), and type = "cor" (alias: corr()) models a correlation matrix.

Usage

varcov(data, type = c("cov", "chol", "prec", "ggm", "cor"),
                   sigma = "full", kappa = "full", omega = "full",
                   lowertri = "full", delta = "diag", rho = "full", SD =
                   "full", mu, tau, vars, ordered = character(0), groups,
                   covs, means, nobs, missing = "listwise", equal =
                   "none", baseline_saturated = TRUE, estimator =
                   "default", optimizer, storedata = FALSE, WLS.W,
                   sampleStats, meanstructure, corinput, verbose = FALSE,
                   covtype = c("choose", "ML", "UB"), standardize =
                   c("none", "z", "quantile"), fullFIML = FALSE,
                   bootstrap = FALSE, boot_sub, boot_resample)
cholesky(...)
precision(...)
prec(...)
ggm(...)
corr(...)

Arguments

data

A data frame encoding the data used in the analysis. Can be missing if covs and nobs are supplied.

type

The type of model used. See description.

sigma

Only used when type = "cov". Either "full" to estimate every element freely, "diag" to only include diagonal elements, or a matrix of the dimensions node x node with 0 encoding a fixed to zero element, 1 encoding a free to estimate element, and higher integers encoding equality constrains. For multiple groups, this argument can be a list or array with each element/slice encoding such a matrix.

kappa

Only used when type = "prec". Either "full" to estimate every element freely, "diag" to only include diagonal elements, or a matrix of the dimensions node x node with 0 encoding a fixed to zero element, 1 encoding a free to estimate element, and higher integers encoding equality constrains. For multiple groups, this argument can be a list or array with each element/slice encoding such a matrix.

omega

Only used when type = "ggm". Either "full" to estimate every element freely, "zero" to set all elements to zero, or a matrix of the dimensions node x node with 0 encoding a fixed to zero element, 1 encoding a free to estimate element, and higher integers encoding equality constrains. For multiple groups, this argument can be a list or array with each element/slice encoding such a matrix.

lowertri

Only used when type = "chol". Either "full" to estimate every element freely, "diag" to only include diagonal elements, or a matrix of the dimensions node x node with 0 encoding a fixed to zero element, 1 encoding a free to estimate element, and higher integers encoding equality constrains. For multiple groups, this argument can be a list or array with each element/slice encoding such a matrix.

delta

Only used when type = "ggm". Either "diag" or "zero" (not recommended), or a matrix of the dimensions node x node with 0 encoding a fixed to zero element, 1 encoding a free to estimate element, and higher integers encoding equality constrains. For multiple groups, this argument can be a list or array with each element/slice encoding such a matrix.

rho

Only used when type = "cor". Either "full" to estimate every element freely, "zero" to set all elements to zero, or a matrix of the dimensions node x node with 0 encoding a fixed to zero element, 1 encoding a free to estimate element, and higher integers encoding equality constrains. For multiple groups, this argument can be a list or array with each element/slice encoding such a matrix.

SD

Only used when type = "cor". Either "diag" or "zero" (not recommended), or a matrix of the dimensions node x node with 0 encoding a fixed to zero element, 1 encoding a free to estimate element, and higher integers encoding equality constrains. For multiple groups, this argument can be a list or array with each element/slice encoding such a matrix.

mu

Optional vector encoding the mean structure. Set elements to 0 to indicate fixed to zero constrains, 1 to indicate free means, and higher integers to indicate equality constrains. For multiple groups, this argument can be a list or array with each element/column encoding such a vector.

tau

Optional list encoding the thresholds per variable.

vars

An optional character vector encoding the variables used in the analyis. Must equal names of the dataset in data.

groups

An optional string indicating the name of the group variable in data.

covs

A sample variance–covariance matrix, or a list/array of such matrices for multiple groups. Make sure covtype argument is set correctly to the type of covariances used.

means

A vector of sample means, or a list/matrix containing such vectors for multiple groups.

nobs

The number of observations used in covs and means, or a vector of such numbers of observations for multiple groups.

covtype

If 'covs' is used, this is the type of covariance (maximum likelihood or unbiased) the input covariance matrix represents. Set to "ML" for maximum likelihood estimates (denominator n) and "UB" to unbiased estimates (denominator n-1). The default will try to find the type used, by investigating which is most likely to result from integer valued datasets.

missing

How should missingness be handled in computing the sample covariances and number of observations when data is used. Can be "listwise" for listwise deletion, or "pairwise" for pairwise deletion.

equal

A character vector indicating which matrices should be constrained equal across groups.

baseline_saturated

A logical indicating if the baseline and saturated model should be included. Mostly used internally and NOT Recommended to be used manually.

estimator

The estimator to be used. Currently implemented are "ML" for maximum likelihood estimation, "FIML" for full-information maximum likelihood estimation, "ULS" for unweighted least squares estimation, "WLS" for weighted least squares estimation, and "DWLS" for diagonally weighted least squares estimation.

optimizer

The optimizer to be used. Can be one of "nlminb" (the default R nlminb function), "ucminf" (from the optimr package), and C++ based optimizers "cpp_L-BFGS-B", "cpp_BFGS", "cpp_CG", "cpp_SANN", and "cpp_Nelder-Mead". The C++ optimizers are faster but slightly less stable. Defaults to "nlminb".

storedata

Logical, should the raw data be stored? Needed for bootstrapping (see bootstrap).

standardize

Which standardization method should be used? "none" (default) for no standardization, "z" for z-scores, and "quantile" for a non-parametric transformation to the quantiles of the marginal standard normal distribution.

WLS.W

Optional WLS weights matrix.

sampleStats

An optional sample statistics object. Mostly used internally.

verbose

Logical, should progress be printed to the console?

ordered

A vector with strings indicating the variables that are ordered catagorical, or set to TRUE to model all variables as ordered catagorical.

meanstructure

Logical, should the meanstructure be modeled explicitly?

corinput

Logical, is the input a correlation matrix?

fullFIML

Logical, should row-wise FIML be used? Not recommended!

bootstrap

Should the data be bootstrapped? If TRUE the data are resampled and a bootstrap sample is created. These must be aggregated using aggregate_bootstraps! Can be TRUE or FALSE. Can also be "nonparametric" (which sets boot_sub = 1 and boot_resample = TRUE) or "case" (which sets boot_sub = 0.75 and boot_resample = FALSE).

boot_sub

Proportion of cases to be subsampled (round(boot_sub * N)).

boot_resample

Logical, should the bootstrap be with replacement (TRUE) or without replacement (FALSE)

...

Arguments sent to varcov

Details

The model used in this family is:

var(y)=Σ\mathrm{var}(\boldsymbol{y} ) = \boldsymbol{\Sigma}

E(y)=μ\mathcal{E}( \boldsymbol{y} ) = \boldsymbol{\mu}

in which the covariance matrix can further be modeled in three ways. With type = "chol" as Cholesky decomposition:

Σ=LL\boldsymbol{\Sigma} = \boldsymbol{L}\boldsymbol{L},

with type = "prec" as Precision matrix:

Σ=K1\boldsymbol{\Sigma} = \boldsymbol{K}^{-1},

and finally with type = "ggm" as Gaussian graphical model:

Σ=Δ(IΩ)(1)Δ\boldsymbol{\Sigma} = \boldsymbol{\Delta}(\boldsymbol{I} - \boldsymbol{\Omega})^(-1) \boldsymbol{\Delta}.

Value

An object of the class psychonetrics

Author(s)

Sacha Epskamp

References

Epskamp, S., Rhemtulla, M., & Borsboom, D. (2017). Generalized network psychometrics: Combining network and latent variable models. Psychometrika, 82(4), 904-927.

See Also

lvm, var1, dlvm1

Examples

# Load bfi data from psych package:
library("psychTools")
data(bfi)

# Also load dplyr for the pipe operator:
library("dplyr")

# Let's take the agreeableness items, and gender:
ConsData <- bfi %>% 
  select(A1:A5, gender) %>% 
  na.omit # Let's remove missingness (otherwise use Estimator = "FIML)

# Define variables:
vars <- names(ConsData)[1:5]

# Saturated estimation:
mod_saturated <- ggm(ConsData, vars = vars)

# Run the model:
mod_saturated <- mod_saturated %>% runmodel

# We can look at the parameters:
mod_saturated %>% parameters

# Labels:
labels <- c(
  "indifferent to the feelings of others",
  "inquire about others' well-being",
  "comfort others",
  "love children",
  "make people feel at ease")
  
# Plot CIs:
CIplot(mod_saturated,  "omega", labels = labels, labelstart = 0.2)



# We can also fit an empty network:
mod0 <- ggm(ConsData, vars = vars, omega = "zero")

# Run the model:
mod0 <- mod0 %>% runmodel

# We can look at the modification indices:
mod0 %>% MIs

# To automatically add along modification indices, we can use stepup:
mod1 <- mod0 %>% stepup

# Let's also prune all non-significant edges to finish:
mod1 <- mod1 %>% prune

# Look at the fit:
mod1 %>% fit

# Compare to original (baseline) model:
compare(baseline = mod0, adjusted = mod1)

# We can also look at the parameters:
mod1 %>% parameters

# Or obtain the network as follows:
getmatrix(mod1, "omega")