tests/testthat/test-gee.R

In ggeffects: Create Tidy Data Frames of Marginal Effects for 'ggplot' from Model Outputs

if (requiet("testthat") && requiet("ggeffects") && requiet("emmeans") && requiet("gee")) {
  data(warpbreaks)
  m1 <- suppressMessages(gee::gee(breaks ~ tension, id = wool, data = warpbreaks, silent = TRUE))

  test_that("ggpredict", {
    p <- ggpredict(m1, "tension")
    expect_equal(p$predicted[1], 36.38889, tolerance = 1e-3)
  })

  test_that("ggemmeans", {
    p <- ggemmeans(m1, "tension")
    expect_equal(p$predicted[1], 36.38889, tolerance = 1e-3)
  })

  test_that("ggemmeans, binomial", {
    skip_if_not_installed("insight", "0.19.2")
    set.seed(123)
    n <- 600
    dat <- data.frame(
      depression = rbinom(n, 1, prob = 0.15),
      drug = rbinom(n, 1, prob = 0.5),
      time = rep(1:3, n / 3),
      id = rep(1:200, each = 3)
    )
    junk <- capture.output({
      dep_gee <- suppressMessages(gee::gee(depression ~ drug * time,
        data = dat,
        id = id,
        family = binomial,
        corstr = "independence"
      ))
    })
    out <- ggemmeans(dep_gee, c("drug", "time"))
    expect_equal(out$predicted, c(0.165, 0.1421, 0.1219, 0.1511, 0.1622, 0.1738), tolerance = 1e-2)
    out <- ggpredict(dep_gee, c("drug", "time"))
    expect_equal(out$predicted, c(0.165, 0.1421, 0.1219, 0.1511, 0.1622, 0.1738), tolerance = 1e-2)
  })
}