conquestr (version 0.9.96)

plotMCC: plotMCC

Description

Creates a plot of an item characteristic curve (by response category). For a dichotomous item, this will yield a single curve, for polytomous items this will produce a curve for each response category. Note this is not for use with `rout` files. See the generic function `plotRout` for plotting rout files.

Usage

plotMCC(item, data, range = c(-6, 6), e_linetype = "bins", bins = 6)

Value

A ggplot2 object.

Arguments

item

Item parameters for a single item.

data

Two vectors of data in an _n_ by 2 matrix or data frame, where _n_ are the cases in your analysis. The first vector should be item responses. the second vector should be estimated person abilities.

range

Lower and upper bounds to plot over (defaults to c(-6, 6) OR the minimum and maximum estimated ability, whichever is larger).

e_linetype

A string. Should the empirical lines be based on "bins", or "regression". Defaults to "bins"

bins

If _e\_linetype_ is "bins", how many bins should be used to chunk the empirical lines? defaults to 6. Ignored otherwise.

Examples

myRout <- ConQuestRout()
myPlot<- plotRout(myRout)
if (FALSE) {
# if you run the above example you will have an ICC plot in the object `myPlot`.
plot(myPlot)
}