ifile: Item and Person Summary Files

In Rwinsteps: Running Winsteps in R

Description

An “ifile” is a data frame containing statistical output for a set of items. A “pfile” is a data frame containing statistical output for a group of people, or examinees. These functions create, read, and convert to “ifile” and “pfile” objects.

Usage

ifile(measure, entry = 1:length(measure), ...)

pfile(measure, entry = 1:length(measure), ...)

as.ifile(x)

as.pfile(x)

read.ifile(filename, skip = 1, col.names, sep = ",", ...)

read.pfile(filename, skip = 1, col.names, sep = ",", ...)

Arguments

measure	numeric vector of item locations
entry	item position numbers, normally a sequence from 1 to the number of items
x	a data frame with items as rows, containing, at a minimum, columns titled “measure” and “entry”
filename	path to the file, which is assumed to be a table in 'csv' format
skip	number of header lines to skip, defaulting to 1
col.names	vector of column names to be added to the file after it is read in
sep	the field separator character, sent to read.table, defaulting to comma separated values
...	For ifile and pfile, additional variables, as vectors of the same length as measure, to be included in the ifile or pfile; for read.ifile and read.pfile, further arguments passed to read.table

Details

The ifile contains item-level information, and the pfile person-level information, based on a fit of the Rasch model to a set of item-response data.

Using read.ifile and read.pfile, the ifile and pfile are read in as 'csv' files, i.e., tables with sep = ",". These functions are simple wrappers for the function read.csv.

Value

A data frame of class “ifile” or “pfile”

Author(s)

Anthony Albano [e-mail]

See Also

read.ifile, plot.ifile

Examples

imeasure <- rnorm(5)
ifile(imeasure, name = paste("item", 1:5, sep = ""))
as.ifile(data.frame(measure = imeasure, entry = 1:5))

pmeasure <- rnorm(3)
pfile(pmeasure, name = c("Skeeter", "Shira", "Soto"))
as.pfile(data.frame(measure = pmeasure, entry = 1:3))

Rwinsteps documentation built on May 2, 2019, 1:08 p.m.