tests/testthat/test-contrasts_polynomial.R

In contrastable: Consistent Contrast Coding for Factors

test_that("Polynomial verification works", {
  cmat <- contr.poly(5)
  cmat2 <- unname(contr.poly(5))
  tstdf <- data.frame(x = gl(5, 1),
                      y = gl(100, 1))

  poly_results1 <- enlist_contrasts(tstdf, x ~ cmat | c("a", "b", "c", "d"),
                                    verbose = FALSE)
  poly_results2 <- enlist_contrasts(tstdf, x ~ cmat, verbose = FALSE)
  poly_results3 <- enlist_contrasts(tstdf, x ~ cmat2, verbose = FALSE)

  expect_equal(c("a", "b", "c", "d"), colnames(poly_results1[["x"]]))
  expect_equal(poly_results2, poly_results3)


})

test_that("Error with too many levels", {
  tstdf <- data.frame(a = gl(100, 1),
                      b = gl(100, 1, ordered = TRUE))

  expect_error(
    enlist_contrasts(tstdf, a ~ contr.poly, verbose = FALSE),
    "cannot be represented accurately enough"
  )

  expect_error(
    set_contrasts(tstdf, a ~ contr.poly, verbose = FALSE),
    "cannot be represented accurately enough"
  )

  expect_error(
    glimpse_contrasts(tstdf, show_all_factors = TRUE, verbose = FALSE),
    "Convert `b` to unordered"
  )
})