Plot Test Reference Profile (TRP) from exametrika

This function takes exametrika output as input and generates a Test Reference Profile (TRP) plot using ggplot2. TRP shows the number of students in each latent class/rank (bar graph) and the expected test score for each class/rank (line graph).

Usage

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

Arguments

data: An object from exametrika: LCA, LRA, Biclustering, nominalBiclustering, ordinalBiclustering, ratedBiclustering, IRM, LDLRA, LDB, or BINET output.
Num_Students: Logical. If TRUE (default), display the number of students on each bar.
title: Logical or character. If TRUE (default), display the auto-generated title. If FALSE, no title. If a character string, use it as a custom title.
colors: Character vector of length 2. First element is the bar fill color, second is the line/point color. If NULL (default), uses gray for bars and black for line/points.
linetype: Character or numeric specifying the line type for the expected score line. 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 single ggplot object with dual y-axes showing both the student distribution and expected scores.

Details

The Test Reference Profile provides an overview of the latent structure. The bar graph shows how students are distributed across classes/ranks, while the line graph shows the expected test score for each class/rank. In well-fitted models, expected scores should increase monotonically with class/rank number.

Examples

library(exametrika)
result <- LRA(J15S500, nrank = 5)
plot <- plotTRP_gg(result)
plot