ltm: plot.descript – R documentation

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plot.descript

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 d.rizopoulos@erasmusmc.nl

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

Latent Trait Models under IRT

v1.1-1

GPL (>= 2)

Authors

Dimitris Rizopoulos <d.rizopoulos@erasmusmc.nl>

Initial release

2018-04-17