Package 'nullabor' reference manual

Title:	Tools for Graphical Inference
Description:	Tools for visual inference. Generate null data sets and null plots using permutation and simulation. Calculate distance metrics for a lineup, and examine the distributions of metrics.
Authors:	Hadley Wickham [aut, ctb] , Niladri Roy Chowdhury [aut, ctb], Di Cook [aut, cre] , Heike Hofmann [aut, ctb]
Maintainer:	Di Cook <[email protected]>
License:	GPL (>= 2)
Version:	0.3.12
Built:	2024-08-21 06:04:22 UTC
Source:	CRAN

Conversion rate of 1 Australian Doller (AUD) to 1 US Dollar

Description

The dataset consists of the daily exchange rates of 1 Australian Dollar to 1 US Dollar between Jan 9 2018 and Feb 21 2018.

Binned Distance

Description

Data X is binned into X.bin bins in x-direction and Y.bins in y-direction. The number of points in each cell is then counted. Same is done for data PX. An euclidean distance is calculated between the number of points in each cell between X and PX.

Usage

bin_dist(X, PX, lineup.dat = lineup.dat, X.bin = 5, Y.bin = 5)
bin_dist(X, PX, lineup.dat = lineup.dat, X.bin = 5, Y.bin = 5)

Arguments

`X`	a data.frame with two variables, the first two columns are used
`PX`	another data.frame with two variables, the first two columns are used
`lineup.dat`	lineup data so that the binning is done based on the lineup data and not the individual plots, by default lineup.dat = lineup.dat ; if one wishes to calculate the binned distance between two plots, one should use lineup.dat = NULL
`X.bin`	number of bins on the x-direction, by default X.bin = 5
`Y.bin`	number of bins on the y-direction, by default Y.bin = 5

Value

distance between X and PX

Examples

with(mtcars, bin_dist(data.frame(wt, mpg), data.frame(sample(wt), mpg),
lineup.dat = NULL))
with(mtcars, bin_dist(data.frame(wt, mpg), data.frame(sample(wt), mpg),
lineup.dat = NULL))

Distance based on side by side Boxplots

Description

Assuming that data set X consists of a categorical group variable a numeric value, a summary of the first quartile, median and third quartile of this value is calculated for each group. The extent (as absolute difference) of the minimum and maximum value across groups is computed for first quartile, median and third quartile. Same is done for data PX. Finally an euclidean distance is calculated between the absolute differences of X and PX.

Usage

box_dist(X, PX)
box_dist(X, PX)

Arguments

`X`	a data.frame with one factor variable and one continuous variable
`PX`	a data.frame with one factor variable and one continuous variable

Value

distance between X and PX

Examples

if(require('dplyr')) {
  with(mtcars,
    box_dist(data.frame(as.factor(am), mpg),
    data.frame(as.factor(sample(am)), mpg))
  )
}
if(require('dplyr')) {
  with(mtcars,
    box_dist(data.frame(as.factor(am), mpg),
    data.frame(as.factor(sample(am)), mpg))
  )
}

Calculating the difference between true plot and the null plot with the maximum distance.

Description

Distance metric is used to calculate the mean distance between the true plot and all the null plots in a lineup. The difference between the mean distance of the true plot and the maximum mean distance of the null plots is calculated.

Usage

calc_diff(lineup.dat, var, met, pos, dist.arg = NULL, m = 20)
calc_diff(lineup.dat, var, met, pos, dist.arg = NULL, m = 20)

Arguments

`lineup.dat`	lineup data to get the lineup
`var`	a vector of names of the variables to be used to calculate the difference
`met`	distance metric needed to calculate the distance as a character
`pos`	position of the true plot in the lineup
`dist.arg`	a list or vector of inputs for the distance metric met; NULL by default
`m`	number of plots in the lineup, by default m = 20

Value

difference between the mean distance of the true plot and the maximum mean distance of the null plots

Examples

if(require('dplyr')){
lineup.dat <- lineup(null_permute('mpg'), mtcars, pos = 1)
calc_diff(lineup.dat, var = c('mpg', 'wt'), met = 'bin_dist',
dist.arg = list(lineup.dat = lineup.dat, X.bin = 5, Y.bin = 5), pos = 1, m = 8)}

if(require('dplyr')){
calc_diff(lineup(null_permute('mpg'), mtcars, pos = 1), var = c('mpg', 'wt'), met = 'reg_dist',
dist.arg = NULL, pos = 1, m = 8)}
if(require('dplyr')){
lineup.dat <- lineup(null_permute('mpg'), mtcars, pos = 1)
calc_diff(lineup.dat, var = c('mpg', 'wt'), met = 'bin_dist',
dist.arg = list(lineup.dat = lineup.dat, X.bin = 5, Y.bin = 5), pos = 1, m = 8)}

if(require('dplyr')){
calc_diff(lineup(null_permute('mpg'), mtcars, pos = 1), var = c('mpg', 'wt'), met = 'reg_dist',
dist.arg = NULL, pos = 1, m = 8)}

Calculating the mean distances of each plot in the lineup.

Description

Distance metric is used to calculate the mean distance between the true plot and all the null plots in a lineup. The mean distances of each null plot to all the other null plots are calculated. The mean distances are returned for all the plots in the lineup.

Usage

calc_mean_dist(lineup.dat, var, met, pos, dist.arg = NULL, m = 20)
calc_mean_dist(lineup.dat, var, met, pos, dist.arg = NULL, m = 20)

Arguments

`lineup.dat`	lineup data of the lineup
`var`	a vector of names of the variables to be used to calculate the mean distances
`met`	distance metric needed to calculate the distance as a character
`pos`	position of the true plot in the lineup
`dist.arg`	a list or vector of inputs for the distance metric met; NULL by default
`m`	number of plots in the lineup, by default m = 20

Value

the mean distances of each plot in the lineup

Examples

if(require('dplyr')){
calc_mean_dist(lineup(null_permute('mpg'), mtcars, pos = 1), var = c('mpg', 'wt'),
met = 'reg_dist', pos = 1, m = 10)}
if(require('dplyr')){
calc_mean_dist(lineup(null_permute('mpg'), mtcars, pos = 1), var = c('mpg', 'wt'),
met = 'reg_dist', pos = 1, m = 10)}

Use decrypt to reveal the position of the real data.

Description

The real data position is encrypted by the lineup function, and writes this out as a text string. Decrypt, decrypts this text string to reveal which where the real data is.

Usage

decrypt(...)
decrypt(...)

Arguments

...

character vector to decrypt

Examples

decrypt('0uXR2p rut L2O2')
decrypt('0uXR2p rut L2O2')

Empirical distribution of the distance

Description

The empirical distribution of the distance measures is calculated based on the mean distance of each of the null plots from the other null plots in a lineup. At this moment this method works only for null_permute method. This function helps get some assessment of whether the actual data plot is very different from the null plots.

Usage

distmet(
  lineup.dat,
  var,
  met,
  method,
  pos,
  repl = 1000,
  dist.arg = NULL,
  m = 20
)
distmet(
  lineup.dat,
  var,
  met,
  method,
  pos,
  repl = 1000,
  dist.arg = NULL,
  m = 20
)

Arguments

`lineup.dat`	lineup data
`var`	a vector of names of the variables to be used
`met`	distance metric needed to calculate the distance as a character
`method`	method for generating null data sets
`pos`	position of the observed data in the lineup
`repl`	number of sets of null plots selected to obtain the distribution; 1000 by default
`dist.arg`	a list or vector of inputs for the distance metric met; NULL by default
`m`	the number of plots in the lineup; m = 20 by default

Value

lineup has the data used for the calculations

null_values contains new null samples from which to compare nulls in lineup

diff difference in distance between nulls and actual data and that of the null that is most different from other nulls. A negative value means that the actual data plot is similar to the null plots.

closest list of the five closest nulls to the actual data plot

pos position of the actual data plot in the lineup

Examples

# Each of these examples uses a small number of nulls (m=8), and a small number of
# repeated sampling from the null distribution (repl=100), to make it faster to run.
# In your own examples you should think about increasing each of these, at least to the defaults.
## Not run: 
if (require('dplyr')) {
  d <- lineup(null_permute('mpg'), mtcars, pos = 1)
  dd <- distmet(d, var = c('mpg', 'wt'),
    'reg_dist', null_permute('mpg'), pos = 1, repl = 100, m = 8)
  distplot(dd, m=8)
}

## End(Not run)

## Not run: 
d <- lineup(null_permute('mpg'), mtcars, pos=4, n=8)
library(ggplot2)
ggplot(d, aes(mpg, wt)) + geom_point() + facet_wrap(~ .sample, ncol=4)
if (require('dplyr')) {
  dd <- distmet(d, var = c('mpg', 'wt'), 'bin_dist', null_permute('mpg'),
    pos = 4, repl = 100, dist.arg = list(lineup.dat = d, X.bin = 5,
    Y.bin = 5), m = 8)
  distplot(dd, m=8)
}

## End(Not run)

# Example using bin_dist
## Not run: 
if (require('dplyr')) {
  d <- lineup(null_permute('mpg'), mtcars, pos = 1)
  library(ggplot2)
  ggplot(d, aes(mpg, wt)) + geom_point() + facet_wrap(~ .sample, ncol=5)
  dd <- distmet(d, var = c('mpg', 'wt'),
    'bin_dist', null_permute('mpg'), pos = 1, repl = 500,
    dist.arg = list(lineup.dat = d, X.bin = 5, Y.bin = 5))
  distplot(dd)
}

## End(Not run)

# Example using uni_dist
## Not run: 
mod <- lm(wt ~ mpg, data = mtcars)
resid.dat <- data.frame(residual = mod$resid)
d <- lineup(null_dist('residual', dist = 'normal'), resid.dat, pos=19)
ggplot(d, aes(residual)) + geom_histogram(binwidth = 0.25) + facet_wrap(~ .sample, ncol=5)
if (require('dplyr')) {
  dd <- distmet(d, var = 'residual', 'uni_dist', null_dist('residual',
    dist = 'normal'), pos = 19, repl = 500)
  distplot(dd)
}

## End(Not run)
# Each of these examples uses a small number of nulls (m=8), and a small number of
# repeated sampling from the null distribution (repl=100), to make it faster to run.
# In your own examples you should think about increasing each of these, at least to the defaults.
## Not run: 
if (require('dplyr')) {
  d <- lineup(null_permute('mpg'), mtcars, pos = 1)
  dd <- distmet(d, var = c('mpg', 'wt'),
    'reg_dist', null_permute('mpg'), pos = 1, repl = 100, m = 8)
  distplot(dd, m=8)
}

## End(Not run)

## Not run: 
d <- lineup(null_permute('mpg'), mtcars, pos=4, n=8)
library(ggplot2)
ggplot(d, aes(mpg, wt)) + geom_point() + facet_wrap(~ .sample, ncol=4)
if (require('dplyr')) {
  dd <- distmet(d, var = c('mpg', 'wt'), 'bin_dist', null_permute('mpg'),
    pos = 4, repl = 100, dist.arg = list(lineup.dat = d, X.bin = 5,
    Y.bin = 5), m = 8)
  distplot(dd, m=8)
}

## End(Not run)

# Example using bin_dist
## Not run: 
if (require('dplyr')) {
  d <- lineup(null_permute('mpg'), mtcars, pos = 1)
  library(ggplot2)
  ggplot(d, aes(mpg, wt)) + geom_point() + facet_wrap(~ .sample, ncol=5)
  dd <- distmet(d, var = c('mpg', 'wt'),
    'bin_dist', null_permute('mpg'), pos = 1, repl = 500,
    dist.arg = list(lineup.dat = d, X.bin = 5, Y.bin = 5))
  distplot(dd)
}

## End(Not run)

# Example using uni_dist
## Not run: 
mod <- lm(wt ~ mpg, data = mtcars)
resid.dat <- data.frame(residual = mod$resid)
d <- lineup(null_dist('residual', dist = 'normal'), resid.dat, pos=19)
ggplot(d, aes(residual)) + geom_histogram(binwidth = 0.25) + facet_wrap(~ .sample, ncol=5)
if (require('dplyr')) {
  dd <- distmet(d, var = 'residual', 'uni_dist', null_dist('residual',
    dist = 'normal'), pos = 19, repl = 500)
  distplot(dd)
}

## End(Not run)

Plotting the distribution of the distance measure

Description

The permutation distribution of the distance measure is plotted with the distances for the null plots. Distance measure values for the null plots and the true plot are overlaid.

Usage

distplot(dat, m = 20)
distplot(dat, m = 20)

Arguments

`dat`	output from `distmet`
`m`	the number of plots in the lineup; m = 20 by default

Examples

## Not run: 
if (require('dplyr')) {
  d <- lineup(null_permute('mpg'), mtcars, pos = 1)
  library(ggplot2)
  ggplot(d, aes(mpg, wt)) + geom_point() + facet_wrap(~.sample)
  distplot(distmet(d, var = c('mpg', 'wt'), 'reg_dist', null_permute('mpg'),
    pos = 1, repl = 100, m = 8), m = 8)
}

## End(Not run)
## Not run: 
if (require('dplyr')) {
  d <- lineup(null_permute('mpg'), mtcars, pos = 1)
  library(ggplot2)
  ggplot(d, aes(mpg, wt)) + geom_point() + facet_wrap(~.sample)
  distplot(distmet(d, var = c('mpg', 'wt'), 'reg_dist', null_permute('mpg'),
    pos = 1, repl = 100, m = 8), m = 8)
}

## End(Not run)

Polls and election results from the 2012 US Election

Description

Polls and election results from the 2012 US Election

Format

A list with two data frames: polls is a data frame of 51 rows and 4 variables

State: State name
Electoral.vote: Number of electoral votes in the 2012 election
Margin: Margin between the parties with the highest number of votes and second highest number of votes. These margins are based on polls.
Democrat: logical vector True, if the democratic party is the majority party in this state.

'election' is a data frame of 51 rows and 5 variables

State: State name
Candidate: character string of the winner: Romney or Obama
Electoral.vote: Number of electoral votes in the 2012 election
Margin: Margin between the parties with the highest number of votes and second highest number of votes. These margins are based on the actual election outcome
Democrat: logical vector True, if the democratic party is the majority party in this state.

Los Angeles Lakers play-by-play data.

Description

Play by play data from all games played by the Los Angeles lakers in the 2008/2009 season.

The line-up protocol.

Description

In this protocol the plot of the real data is embedded amongst a field of plots of data generated to be consistent with some null hypothesis. If the observe can pick the real data as different from the others, this lends weight to the statistical significance of the structure in the plot. The protocol is described in Buja, Cook, Hofmann, Lawrence, Lee, Swayne, Wickham (2009) Statistical inference for exploratory data analysis and model diagnostics, Phil. Trans. R. Soc. A, 367, 4361-4383.

Usage

lineup(method, true = NULL, n = 20, pos = sample(n, 1), samples = NULL)
lineup(method, true = NULL, n = 20, pos = sample(n, 1), samples = NULL)

Arguments

`method`	method for generating null data sets
`true`	true data set. If `NULL`, `find_plot_data` will attempt to extract it from the current ggplot2 plot.
`n`	total number of samples to generate (including true data)
`pos`	position of true data. Leave missing to pick position at random. Encryped position will be printed on the command line, `decrypt` to understand.
`samples`	samples generated under the null hypothesis. Only specify this if you don't want lineup to generate the data for you.

Details

Generate n - 1 null datasets and randomly position the true data. If you pick the real data as being noticeably different, then you have formally established that it is different to with p-value 1/n.

Examples

library(ggplot2)
ggplot(lineup(null_permute('mpg'), mtcars), aes(mpg, wt)) +
  geom_point() +
  facet_wrap(~ .sample)
ggplot(lineup(null_permute('cyl'), mtcars),
       aes(mpg, .sample, colour = factor(cyl))) +
       geom_point()
library(ggplot2)
ggplot(lineup(null_permute('mpg'), mtcars), aes(mpg, wt)) +
  geom_point() +
  facet_wrap(~ .sample)
ggplot(lineup(null_permute('cyl'), mtcars),
       aes(mpg, .sample, colour = factor(cyl))) +
       geom_point()

Generate null data with a specific distribution.

Description

Null hypothesis: variable has specified distribution

Usage

null_dist(var, dist, params = NULL)
null_dist(var, dist, params = NULL)

Arguments

`var`	variable name
`dist`	distribution name. One of: beta, cauchy, chisq, exp, f, gamma, geom, lnorm, logis, nbinom, binom, norm, pois, t, unif, weibull
`params`	list of parameters of distribution. If `NULL`, will use `fitdistr` to estimate them.

Value

a function that given data generates a null data set. For use with lineup or rorschach

Examples

dframe <- data.frame(x = rnorm(150))
library(ggplot2)
# three histograms of normally distributed values
ggplot(
  data=rorschach(method=null_dist("x", "norm"), n = 3, true=dframe)
  ) +
  geom_histogram(aes(x=x, y=..density..), binwidth=0.25) +
  facet_grid(.~.sample) +
  geom_density(aes(x=x), colour="steelblue", size=1)

# uniform distributions are not as easy to recognize as such
dframe$x = runif(150)
ggplot(
  data=rorschach(method=null_dist("x", "uniform",
                 params=list(min=0, max=1)),
  n = 3, true=dframe)) +
  geom_histogram(aes(x=x, y=..density..), binwidth=0.1) +
  facet_grid(.~.sample) +
  geom_density(aes(x=x), colour="steelblue", size=1)
dframe <- data.frame(x = rnorm(150))
library(ggplot2)
# three histograms of normally distributed values
ggplot(
  data=rorschach(method=null_dist("x", "norm"), n = 3, true=dframe)
  ) +
  geom_histogram(aes(x=x, y=..density..), binwidth=0.25) +
  facet_grid(.~.sample) +
  geom_density(aes(x=x), colour="steelblue", size=1)

# uniform distributions are not as easy to recognize as such
dframe$x = runif(150)
ggplot(
  data=rorschach(method=null_dist("x", "uniform",
                 params=list(min=0, max=1)),
  n = 3, true=dframe)) +
  geom_histogram(aes(x=x, y=..density..), binwidth=0.1) +
  facet_grid(.~.sample) +
  geom_density(aes(x=x), colour="steelblue", size=1)

Generate null data with null residuals from a model.

Description

Null hypothesis: variable is linear combination of predictors

Usage

null_lm(f, method = "rotate", ...)
null_lm(f, method = "rotate", ...)

Arguments

`f`	model specification formula, as defined by `lm`
`method`	method for generating null residuals. Built in methods 'rotate', 'pboot' and 'boot' are defined by `resid_rotate`, `resid_pboot` and `resid_boot` respectively
`...`	other arguments passedd onto `method`.

Value

a function that given data generates a null data set. For use with lineup or rorschach

Examples

data(tips)
x <- lm(tip ~ total_bill, data = tips)
tips.reg <- data.frame(tips, .resid = residuals(x), .fitted = fitted(x))
library(ggplot2)
ggplot(lineup(null_lm(tip ~ total_bill, method = 'rotate'), tips.reg)) +
  geom_point(aes(x = total_bill, y = .resid)) +
  facet_wrap(~ .sample)
data(tips)
x <- lm(tip ~ total_bill, data = tips)
tips.reg <- data.frame(tips, .resid = residuals(x), .fitted = fitted(x))
library(ggplot2)
ggplot(lineup(null_lm(tip ~ total_bill, method = 'rotate'), tips.reg)) +
  geom_point(aes(x = total_bill, y = .resid)) +
  facet_wrap(~ .sample)

Generate null data by permuting a variable.

Description

Null hypothesis: variable is independent of others

Usage

null_permute(var)
null_permute(var)

Arguments

var

name of variable to permute

Value

a function that given data generates a null data set. For use with lineup or rorschach

Examples

data(mtcars)
library(ggplot2)
ggplot(data=rorschach(method=null_permute("mpg"), n = 3, true=mtcars)) +
geom_boxplot(aes(x=factor(cyl), y=mpg, fill=factor(cyl))) +facet_grid(.~.sample) +
theme(legend.position="none", aspect.ratio=1)
data(mtcars)
library(ggplot2)
ggplot(data=rorschach(method=null_permute("mpg"), n = 3, true=mtcars)) +
geom_boxplot(aes(x=factor(cyl), y=mpg, fill=factor(cyl))) +facet_grid(.~.sample) +
theme(legend.position="none", aspect.ratio=1)

Generate null data by simulating from a time series model.

Description

Null hypothesis: data follows a time series model using auto.arima from the forecast package

Usage

null_ts(var, modelfn)
null_ts(var, modelfn)

Arguments

`var`	variable to model as a time series
`modelfn`	method for simulating from ts model.

Value

a function that given data generates a null data set. For use with lineup or rorschach

Examples

require(forecast)
require(ggplot2)
require(dplyr)
data(aud)
l <- lineup(null_ts("rate", auto.arima), aud)
ggplot(l, aes(x=date, y=rate)) + geom_line() +
  facet_wrap(~.sample, scales="free_y") +
  theme(axis.text = element_blank()) +
  xlab("") + ylab("")
l_dif <- l %>%
  group_by(.sample) %>%
  mutate(d=c(NA,diff(rate))) %>%
  ggplot(aes(x=d)) + geom_density() +
  facet_wrap(~.sample)
require(forecast)
require(ggplot2)
require(dplyr)
data(aud)
l <- lineup(null_ts("rate", auto.arima), aud)
ggplot(l, aes(x=date, y=rate)) + geom_line() +
  facet_wrap(~.sample, scales="free_y") +
  theme(axis.text = element_blank()) +
  xlab("") + ylab("")
l_dif <- l %>%
  group_by(.sample) %>%
  mutate(d=c(NA,diff(rate))) %>%
  ggplot(aes(x=d)) + geom_density() +
  facet_wrap(~.sample)

Finds the number of bins in x and y direction which gives the maximum binned distance.

Description

This function finds the optimal number of bins in both x and y direction which should be used to calculate the binned distance. The binned distance is calculated for each combination of provided choices of number of bins in x and y direction and finds the difference using calc_diff for each combination. The combination for which the difference is maximum should be used.

Usage

opt_bin_diff(
  lineup.dat,
  var,
  xlow,
  xhigh,
  ylow,
  yhigh,
  pos,
  plot = FALSE,
  m = 20
)
opt_bin_diff(
  lineup.dat,
  var,
  xlow,
  xhigh,
  ylow,
  yhigh,
  pos,
  plot = FALSE,
  m = 20
)

Arguments

`lineup.dat`	lineup data to get the lineup
`var`	a list of names of the variables to be used to calculate the difference
`xlow`	the lowest value of number of bins on the x-direction
`xhigh`	the highest value of number of bins on the x-direction
`ylow`	the lowest value of number of bins on the y-direction
`yhigh`	the highest value of number of bins on the y-direction
`pos`	position of the true plot in the lineup
`plot`	LOGICAL; if true, returns a tile plot for the combinations of number of bins with the differences as weights
`m`	number of plots in the lineup, by default m = 20

Value

a dataframe with the number of bins and differences the maximum mean distance of the null plots

Examples

if(require('dplyr')){
opt_bin_diff(lineup(null_permute('mpg'), mtcars, pos = 1), var = c('mpg', 'wt'),
2, 5, 4, 8, pos = 1, plot = TRUE, m = 8)
}
if(require('dplyr')){
opt_bin_diff(lineup(null_permute('mpg'), mtcars, pos = 1), var = c('mpg', 'wt'),
2, 5, 4, 8, pos = 1, plot = TRUE, m = 8)
}

P-value calculations.

Description

These set of functions allow the user to calculate a p-value from the lineup after it has been evaluated by K independent observers. The different functions accommodate different lineup construction and showing to observers. Details are in the papers Majumder et al (2012) JASA, and Hofmann et al (2015). We distinguish between three different scenarios:

Scenario I: in each of K evaluations a different data set and a different set of (m-1) null plots is shown.
Scenario II: in each of K evaluations the same data set but a different set of (m-1) null plots is shown.
Scenario III: the same lineup, i.e. same data and same set of null plots, is shown to K different observers.

Usage

pvisual(
  x,
  K,
  m = 20,
  N = 10000,
  type = "scenario3",
  xp = 1,
  target = 1,
  upper.tail = TRUE
)
pvisual(
  x,
  K,
  m = 20,
  N = 10000,
  type = "scenario3",
  xp = 1,
  target = 1,
  upper.tail = TRUE
)

Arguments

`x`	number of observed picks of the data plot
`K`	number of evaluations
`m`	size of the lineup
`N`	MC parameter: number of replicates on which MC probabilities are based. Higher number of replicates will decrease MC variability.
`type`	type of simulation used: scenario 3 assumes that the same lineup is shown in all K evaluations
`xp`	exponent used, defaults to 1
`target`	integer value identifying the location of the data plot
`upper.tail`	compute probabilities P(X >= x). Be aware that the use of this parameter is not consistent with the other distribution functions in base. There, a value of P(X > x) is computed for upper.tail=TRUE.

Value

Vector/data frame. For comparison a p value based on a binomial distribution is provided as well.

Examples

pvisual(15, 20, m=3) # triangle test
pvisual(15, 20, m=3) # triangle test

Distance based on the regression parameters

Description

Dataset X is binned into 5 bins in x-direction. A regression line is fitted to the data in each bin and the regression coefficients are noted. Same is done for dataset PX. An euclidean distance is calculated between the two sets of regression parameters. If the relationship between X and PX looks linear, number of bins should be equal to 1.

Usage

reg_dist(X, PX, nbins = 1, intercept = TRUE, scale = TRUE)
reg_dist(X, PX, nbins = 1, intercept = TRUE, scale = TRUE)

Arguments

`X`	a data.frame with two variables, the first column giving the explanatory variable and the second column giving the response variable
`PX`	another data.frame with two variables, the first column giving the explanatory variable and the second column giving the response variable
`nbins`	number of bins on the x-direction, by default nbins = 1
`intercept`	include the distances between intercepts?
`scale`	logical value: should the variables be scaled before computing regression coefficients?

Value

distance between X and PX

Examples

with(mtcars, reg_dist(data.frame(wt, mpg), data.frame(sample(wt), mpg)))
with(mtcars, reg_dist(data.frame(wt, mpg), data.frame(sample(wt), mpg)))

Bootstrap residuals.

Description

For use with null_lm

Usage

resid_boot(model, data)
resid_boot(model, data)

Arguments

`model`	to extract residuals from
`data`	used to fit model

Parametric bootstrap residuals.

Description

For use with null_lm

Usage

resid_pboot(model, data)
resid_pboot(model, data)

Arguments

`model`	to extract residuals from
`data`	used to fit model

Rotation residuals.

Description

For use with null_lm

Usage

resid_rotate(model, data)
resid_rotate(model, data)

Arguments

`model`	to extract residuals from
`data`	used to fit model

Residuals simulated by a normal model, with specified sigma

Description

For use with null_lm

Usage

resid_sigma(model, data, sigma = 1)
resid_sigma(model, data, sigma = 1)

Arguments

`model`	to extract residuals from
`data`	used to fit model
`sigma`	a specific sigma to model

The Rorschach protocol.

Description

This protocol is used to calibrate the eyes for variation due to sampling. All plots are typically null data sets, data that is consistent with a null hypothesis. The protocol is described in Buja, Cook, Hofmann, Lawrence, Lee, Swayne, Wickham (2009) Statistical inference for exploratory data analysis and model diagnostics, Phil. Trans. R. Soc. A, 367, 4361-4383.

Usage

rorschach(method, true = NULL, n = 20, p = 0)
rorschach(method, true = NULL, n = 20, p = 0)

Arguments

`method`	method for generating null data sets
`true`	true data set. If `NULL`, `find_plot_data` will attempt to extract it from the current ggplot2 plot.
`n`	total number of samples to generate (including true data)
`p`	probability of including true data with null data.

Sample size calculator

Description

This function calculates a table of sample sizes for with an experiment, given a lineup size, and estimates of the detection rate.

Usage

sample_size(n = 53:64, m = 20, pA = seq(1/20, 1/3, 0.01), conf = 0.95)
sample_size(n = 53:64, m = 20, pA = seq(1/20, 1/3, 0.01), conf = 0.95)

Arguments

`n`	range of sample sizes to check, default is 53:64
`m`	linup size, default 20
`pA`	range of estimated detection rates to consider, default is seq(1/20, 1/3, 0.01)
`conf`	confidence level to use to simulate from binomial

Examples

pow <- sample_size()
pow
library(ggplot2)
library(viridis)
ggplot(pow, aes(x=n, y=pA, fill=prob, group=pA)) +
  geom_tile() +
  scale_fill_viridis_c("power") +
  ylab("detect rate (pA)") + xlab("sample size (n)") +
  theme_bw()
pow <- sample_size()
pow
library(ggplot2)
library(viridis)
ggplot(pow, aes(x=n, y=pA, fill=prob, group=pA)) +
  geom_tile() +
  scale_fill_viridis_c("power") +
  ylab("detect rate (pA)") + xlab("sample size (n)") +
  theme_bw()

Distance based on separation of clusters

Description

The separation between clusters is defined by the minimum distances of a point in the cluster to a point in another cluster. The number of clusters are provided. If not, the hierarchical clustering method is used to obtain the clusters. The separation between the clusters for dataset X is calculated. Same is done for dataset PX. An euclidean distance is then calculated between these separation for X and PX.

Usage

sep_dist(X, PX, clustering = FALSE, nclust = 3, type = "separation")
sep_dist(X, PX, clustering = FALSE, nclust = 3, type = "separation")

Arguments

`X`	a data.frame with two or three columns, the first two columns providing the dataset
`PX`	a data.frame with two or three columns, the first two columns providing the dataset
`clustering`	LOGICAL; if TRUE, the third column is used as the clustering variable, by default FALSE
`nclust`	the number of clusters to be obtained by hierarchical clustering, by default nclust = 3
`type`	character string to specify which measure to use for distance, see ?cluster.stats for details

Value

distance between X and PX

Examples

if(require('fpc')) {
with(mtcars, sep_dist(data.frame(wt, mpg, as.numeric(as.factor(mtcars$cyl))),
              data.frame(sample(wt), mpg, as.numeric(as.factor(mtcars$cyl))),
              clustering = TRUE))
}

if (require('fpc')) {
with(mtcars, sep_dist(data.frame(wt, mpg, as.numeric(as.factor(mtcars$cyl))),
             data.frame(sample(wt), mpg, as.numeric(as.factor(mtcars$cyl))),
             nclust = 3))
}
if(require('fpc')) {
with(mtcars, sep_dist(data.frame(wt, mpg, as.numeric(as.factor(mtcars$cyl))),
              data.frame(sample(wt), mpg, as.numeric(as.factor(mtcars$cyl))),
              clustering = TRUE))
}

if (require('fpc')) {
with(mtcars, sep_dist(data.frame(wt, mpg, as.numeric(as.factor(mtcars$cyl))),
             data.frame(sample(wt), mpg, as.numeric(as.factor(mtcars$cyl))),
             nclust = 3))
}

A theme to minimally strip away the context

Description

Note this is not a complete theme hence why there are no arguments.

Usage

theme_strip()
theme_strip()

Examples

library(ggplot2)
ggplot(cars, aes(dist, speed)) + theme_strip()

library(ggplot2)
ggplot(cars, aes(dist, speed)) + theme_strip()

Tipping data

Description

One waiter recorded information about each tip he received over a period of a few months working in one restaurant. He collected several variables:

Usage

tips
tips

Format

A data frame with 244 rows and 7 variables

Details

tip in dollars,
bill in dollars,
sex of the bill payer,
whether there were smokers in the party,
day of the week,
time of day,
size of the party.

In all he recorded 244 tips. The data was reported in a collection of case studies for business statistics (Bryant & Smith 1995).

References

Bryant, P. G. and Smith, M (1995) Practical Data Analysis: Case Studies in Business Statistics. Homewood, IL: Richard D. Irwin Publishing:

Sample turk results

Description

Subset of data from a Turk experiment, used to show how to compute power of a lineup

Distance for univariate data

Description

The first four moments is calculated for data X and data PX. An euclidean distance is calculated between these moments for X and PX.

Usage

uni_dist(X, PX)
uni_dist(X, PX)

Arguments

`X`	a data.frame where the first column is only used
`PX`	another data.frame where the first column is only used

Value

distance between X and PX

Examples

if(require('moments')){uni_dist(rnorm(100), rpois(100, 2))}
if(require('moments')){uni_dist(rnorm(100), rpois(100, 2))}

Power calculations.

Description

This function simply counts the proportion of people who selected the data plot, in a set of lineups. It adjusts for multiple picks by the same individual, by weighting by the total number of choices.

Usage

visual_power(data, m = 20)
visual_power(data, m = 20)

Arguments

`data`	summary of the results, containing columns id, pic_id, response, detected
`m`	size of the lineup

Value

vector of powers for each pic_id

Examples

data(turk_results)
visual_power(turk_results)
data(turk_results)
visual_power(turk_results)

Wasp gene expression data.

Description

Data from Toth et al (2010) used in Niladri Roy et al (2015)

Package 'nullabor'

Help Index

Conversion rate of 1 Australian Doller (AUD) to 1 US Dollar

Description

Binned Distance

Description

Usage

Arguments

Value

Examples

Distance based on side by side Boxplots

Description

Usage

Arguments

Value

Examples

Calculating the difference between true plot and the null plot with the maximum distance.

Description

Usage

Arguments

Value

Examples

Calculating the mean distances of each plot in the lineup.

Description

Usage

Arguments

Value

Examples

Use decrypt to reveal the position of the real data.

Description

Usage

Arguments

Examples

Empirical distribution of the distance

Description

Usage

Arguments

Value

Examples

Plotting the distribution of the distance measure

Description

Usage

Arguments

Examples

Polls and election results from the 2012 US Election

Description

Format

Los Angeles Lakers play-by-play data.

Description

The line-up protocol.

Description

Usage

Arguments

Details

Examples

Generate null data with a specific distribution.

Description

Usage

Arguments

Value

See Also

Examples

Generate null data with null residuals from a model.

Description

Usage

Arguments

Value

See Also

Examples

Generate null data by permuting a variable.

Description

Usage

Arguments

Value

See Also

Examples

Generate null data by simulating from a time series model.

Description

Usage

Arguments