Plot a paired-comparison equating comparison — plot_btl

Scatter of the two calibrations' common-object locations with the shifted identity line, per-object 95 per cent error bars, and a dotted guide band at the average pooled precision; objects that drift (after the multiplicity adjustment) are highlighted and labelled. The counterpart of plot_equate for Bradley-Terry-Luce scales.

Usage

plot_btl_equate(fit1, fit2, ...)

Arguments

fit1: A fitted object from btl.
fit2: A second btl fit, or a bank data frame with columns object, location, and optionally se.
...: Passed to btl_equate (e.g. alpha, p_adjust).

Value

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

Examples

set.seed(1)
beta <- setNames(seq(-2, 2, length.out = 8), paste0("O", 1:8))
sim <- function(objs) {
  pr <- t(utils::combn(objs, 2))
  d <- data.frame(a = rep(pr[, 1], each = 40), b = rep(pr[, 2], each = 40))
  d$win <- ifelse(runif(nrow(d)) < plogis(beta[d$a] - beta[d$b]), d$a, d$b)
  btl(d, "a", "b", "win")
}
plot_btl_equate(sim(paste0("O", 1:7)), sim(paste0("O", 2:8)))