plot.descript: Descriptive Statistics Plot method

In ltm: Latent Trait Models under IRT

Descriptive Statistics Plot method

Description

The plot method for descript objects currently works for dichotomous response patterns, and produces the xy-plot of the total score versus the proportion of correct responses for each item.

Usage

## S3 method for class 'descript'
plot(x, items = NULL, includeFirstLast = FALSE, xlab, ylab, ...)

Arguments

x	an object inheriting from class descript.
items	a numeric vector indicating which items to plot.
includeFirstLast	logical; if TRUE the first and last total scores categories are included.
xlab, ylab	character string or an expression; see title.
...	extra graphical parameters to be passed to matplot().

Author(s)

Dimitris Rizopoulos [e-mail]

See Also

descript

Examples

## Descriptives for WIRS data:
dsc <- descript(WIRS)
dsc
plot(dsc, includeFirstLast = TRUE, type = "b", lty = 1, pch = 1:6)
legend("topleft", names(WIRS), pch = 1:6, col = 1:6, lty = 1, bty = "n")

ltm documentation built on March 18, 2022, 6:36 p.m.