Plot a test-equating comparison — plot

Scatter of the two calibrations' common-item locations with the shifted identity line and per-item 95 per cent bands; drifting items (BH-adjusted) are highlighted and labelled.

Usage

plot_equate(fit, reference, shift = c("mean", "none"))

Arguments

fit: A fitted object from rasch.
reference: A second rasch fit, or a data frame with columns item, location, and optionally se.
shift: Passed to equate_tests.

Value

Called for its plotting side effect; invisibly the equate_tests result.

Examples

set.seed(1); d <- seq(-1.5, 1.5, length.out = 8)
mk <- function() {
  X <- matrix(rbinom(400 * 8, 1, plogis(outer(rnorm(400), d, "-"))), 400, 8)
  colnames(X) <- paste0("I", 1:8); rasch(X)
}
plot_equate(mk(), mk())