PsySimulate: Simulate psychophysical data

In MixedPsy: Statistical Tools for the Analysis of Psychophysical Data

Description

The function simulates data of a typical psychophysics experiment. For each simulated participant, the function returns the following information: individual slope and intercept coefficients, given the fixed and random effects parameters provided as input; summary of the simulated binomial response to a range of intensity levels between a specified range.

Usage

PsySimulate(
  fixeff = c(-7, 0.0875),
  raneff = c(2.4, -0.002, 2e-06),
  nsubjects = 8,
  ntrials = 40,
  nintervals = 9,
  xint = c(40, 120),
  constant = T
)

Arguments

fixeff	array of fixed effects. First item is the intercept, second item is the slope.
raneff	array of random effects. First item is the intercept, second item is the covariance, third item is the slope.
nsubjects	number of subjects to simulate. Default is 8.
ntrials	number of trials for each stimulus level. Default is 40.
nintervals	number of stimulus levels. Default is 9.
xint	range of the stimulus interval. Default is c(40,120)
constant	logical. If set to FALSE, stimulus levels are randomly generated, uniformly distributed values within the selected interval. otherwise, the X interval is divided in intervals of constant length. Default is TRUE.

Value

PsySimulate returns a simulated dataset. If no input arguments are specified, the function returns a dataset with the same characteristics as simul_data.

See Also

PsychShape for plotting a psychometric function given PSE and JND.

Examples

datafr.S1 <- PsySimulate(fixeff = c(0, 1), xint = c(-5,5), 
nsubject = 1, ntrials = 60, nintervals = 10, constant = FALSE)
library(ggplot2)
g <- ggplot(datafr.S1, aes(X,Longer/Total)) + geom_point()

PsychShape(pse = 0, jnd = qnorm(0.75)/1, ps.link = "probit", 
x.range = c(-5,5), addTo = g, ps.color = "red")

MixedPsy documentation built on Nov. 9, 2021, 1:08 a.m.