plot.rasch {ltm}R Documentation

Plot method for rasch objects

Description

Produces the Item Characteristic Curves or Surfaces for fitted rasch objects.

Usage

plot.rasch(x, cx = NULL, cy = NULL, ...)

Arguments

x an object inheriting from class rasch.
cx the x-coordinate to be passed to legend.
cy the y-coordinate to be passed to legend.
... extra graphical parameters to be passed to lines.

Details

Item characteristic curves (also known as item response functions) show how the probability of a positive response, in each item, increases with the values of the latent variable (ability).

See Also

rasch

Examples


## Item Characteristic Curves for the Wirs data:
m <- rasch(Wirs)
plot(m)

## Item Characteristic Curves for the Lsat data:
m <- rasch(Lsat)
plot(m, cx=1.5, cy=0.4)


[Package ltm version 0.1-1 Index]