plot.irt.prob {plink}R Documentation

Plot Item Characteristic/Category Curves

Description

This function plots item characteristic curves or item category curves using the lattice package.

Usage

## S3 method for class 'irt.prob':
plot(x, y, ..., combine = NULL, item.names = NULL, item.lab = TRUE, 
        panels = 20)

## S3 method for class 'sep.pars':
plot(x, y, ...)

## S3 method for class 'irt.pars':
plot(x, y, ...)

Arguments

x object of class irt.prob, irt.pars, or sep.pars. For the later two classes, probabilities are computed using the function mixed before plotting the curves.
y this argument is not used for these methods
... further arguments passed to or from other methods
combine vector identifying the number of response categories to plot in each panel. If NULL, the curves will be grouped by item. combine is typically used to plot curves for more than one item in a panel.
item.names vector of item names for use in labeling the panels.
item.lab if TRUE, include the item label strip at the top of each panel
panels number of panels to display in the output window. If the number of items is greater than panels, the plots will be created on multiple pages. If NULL, all panels will be plotted on a single page.

Note

When multiple pages are created, the PgUp and PgDn buttons can be used to view the plots on different pages

Author(s)

Jonathan P. Weeks weeksjp@gmail.com

See Also

irt.prob, irt.pars, sep.pars,


[Package plink version 0.1-1 Index]