autoRasch (version 0.2.2)

plot_EVC: Plot The Expected Value Curves

Description

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

Usage

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

Value

There are no values to return. Instead, it plots expected values from the model.

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.

...

Further arguments to be passed.

Examples

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