Plot Item Reference Profile (IRP) from exametrika

This function takes exametrika output as input and generates Item Reference Profile (IRP) plots using ggplot2. IRP shows the probability of a correct response for each item at each latent class or rank level.

Usage

plotIRP_gg(
  data,
  title = TRUE,
  colors = NULL,
  linetype = "dashed",
  show_legend = FALSE,
  legend_position = "right"
)

Arguments

data: An object of class c("exametrika", "LCA"), c("exametrika", "LRA"), or c("exametrika", "LDLRA").
title: Logical or character. If TRUE (default), display an auto-generated title. If FALSE, no title. If a character string, use it as a custom title (only for single-item plots).
colors: Character vector. Color(s) for points and lines. If NULL (default), a colorblind-friendly palette is used.
linetype: Character or numeric specifying the line type. Default is "dashed".
show_legend: Logical. If TRUE, display the legend. Default is FALSE.
legend_position: Character. Position of the legend. One of "right" (default), "top", "bottom", "left", "none".

Value

A list of ggplot objects, one for each item. Each plot shows the correct response rate across latent classes or ranks.

Details

The Item Reference Profile visualizes how item difficulty varies across latent classes (LCA) or ranks (LRA, LDLRA). Items with monotonically increasing profiles indicate good discrimination between classes/ranks.

Examples

library(exametrika)
result <- LRA(J15S500, nrank = 5)
plots <- plotIRP_gg(result)
plots[[1]] # Show IRP for the first item