tests/testthat/test-undersampling.R

In scutr: Balancing Multiclass Datasets for Classification Tasks

context("general undersampling")
rand <- data.frame(cbind(runif(100), as.factor(c(rep(1, 25), rep(2, 75)))))
w_m <- sum(wine$type == 1) %/% 2
r_m <- sum(rand$X2 == 2) %/% 2
for (undersampler in c(
  ls(envir = as.environment("package:scutr"), pattern = "undersample.*"),
  "resample_random"))
{
  func <- get(undersampler)
  subset <- func(wine, 1, "type", w_m)
  rownames(subset) <- 1:nrow(subset)
  test_that("Undersampling produces desired number of rows", {
    expect_equal(nrow(subset), w_m)
  })
  test_that("All rows in undersampled dataset are of the right class", {
    expect_true(all(subset$type == 1))
  })
  test_that("All rows in undersampled dataset are in the original dataset", {
    expect_true(all(apply(
      subset, 1,
      function(row) {
        any(apply(wine, 1, function(row2) {
          all(row == row2)
        }))
      }
    )))
  })
  rand_subset <- func(rand, 2, "X2", r_m)
  test_that("One-dimensional datasets work", {
    expect_equal(nrow(rand_subset), r_m)
    expect_true(all(rand_subset$X2 == 2))
  })
}