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Run flexMIRT from Within R

Source: R/run_flexmirt.R
run_flexmirt.Rd

This function runs flexMIRT (Cai, 2017) from within R by executing a model specified in a flexMIRT syntax file (i.e., *.flexmirt). To use this function, the flexMIRT software must be installed on your system. This interface is especially useful for conducting simulation studies or automating batch analyses involving flexMIRT.

Usage

run_flexmirt(file.syntax, dir.flex = NULL, show.output.on.console = FALSE, ...)

Arguments

file.syntax

A single string or character vector specifying the path(s) to one or more flexMIRT syntax files (with extension *.flexmirt) to be executed. For example: "C:/Users/Data/irtmodel.flexmirt".

dir.flex

A character string specifying the directory where flexMIRT is installed. The folder name typically includes "flexMIRT" (e.g., "flexMIRT3", "flexMIRT 3.6"). If set to NULL, the function searches for flexMIRT in "C:/Program Files" and uses a default path if found (e.g., "C:/Program Files/flexMIRT3").

show.output.on.console

Logical. If TRUE, the output of the system command is printed to the R console. Default is FALSE. See base::system().

...

Additional arguments passed to base::system().

Value

Output files generated by flexMIRT.

Details

When using a version of flexMIRT earlier than 3.6, the directory specified in dir.flex must contain the following six files:

  • WinFlexMIRT.exe

  • FlexMIRT_x64.exe

  • FlexMIRT_x86.exe

  • vpg.dll

  • vpg.licensing.client.dll

  • vpg.licensing.dll

For flexMIRT version 3.6 or later, the directory must include the following five files:

  • WinFlexMIRT.exe

  • vpg.dll

  • vpg.licensing.client.dll

  • vpg.licensing.dll

  • VPGLicenseClientNet.dll

along with a subdirectory named Resources that contains the following two files:

  • flexMIRT_x64_AVX.exe

  • flexMIRT_x86_AVX.exe

References

Cai, L. (2017). flexMIRT 3.5 Flexible multilevel multidimensional item analysis and test scoring (Computer Software). Chapel Hill, NC: Vector Psychometric Group.

Author

Hwanggyu Lim hglim83@gmail.com

Examples

# Examples below will run if the flexMIRT software is installed
# in the default directory "C:/Program Files/flexMIRT3".
# Otherwise, specify the directory where flexMIRT is installed
# using the 'dir.flex' argument.

if (FALSE) { # \dontrun{
# (1) Run a single syntax file
# Load an example flexMIRT syntax file for estimating item parameters using the 2PL model
file.syntax <- system.file("extdata", "2PLM_example.flexmirt", package = "irtQ")

# Run flexMIRT to estimate item parameters for the 2PL model
run_flexmirt(file.syntax = file.syntax, dir.flex = NULL, show.output = TRUE)

# Check the output file
out.file <- system.file("extdata", "2PLM_example-prm.txt", package = "irtQ")
bring.flexmirt(out.file, type = "par")

# (2) Run multiple syntax files
# Load two example flexMIRT syntax files
file.syntax1 <- system.file("extdata", "2PLM_example.flexmirt", package = "irtQ")
file.syntax2 <- system.file("extdata", "3PLM_example.flexmirt", package = "irtQ")

# Run flexMIRT to estimate item parameters for both models
run_flexmirt(file.syntax = c(file.syntax1, file.syntax2), dir.flex = NULL, show.output = FALSE)

# Check the output files
out.file1 <- system.file("extdata", "2PLM_example-prm.txt", package = "irtQ")
out.file2 <- system.file("extdata", "3PLM_example-prm.txt", package = "irtQ")
bring.flexmirt(out.file1, type = "par")
bring.flexmirt(out.file2, type = "par")
} # }