plot_ICC {autoRasch}

Plot The Item Characteristic Curves

Description

This function plots the curve(s) of the estimated ability parameters against the probabilities of responses.

Usage

plot_ICC(
  obj,
  itemno = 5,
  xlab = NULL,
  ylab = NULL,
  xlim = c(-10, 10),
  col = c("green4", "darkorange2", "red2"),
  lty = c(1, 1, 1),
  main = NULL,
  ...
)

Arguments

obj

The object of class 'pcm'.

itemno

A number of the item that is wanted to be plot.

xlab

a title for the x axis.

ylab

a title for the y axis.

xlim

the x limits (x1, x2) of the plot. Note that x1 > x2 is allowed and leads to a ‘reversed axis’. The default value, NULL, indicates that the range of the finite values to be plotted should be used; see plot.default()

col

a vector of plotting colors

lty

a vector of line types.

main

String. Plot title.

...

Further arguments to be passed.

Value

There are no values to return. Instead, it plots the curve of item characteristics from the model.

Examples

res <- pcm(short_poly_data)
plot_ICC(res, itemno = 4)