tests/testthat/test-linear_regression_alt.R

In mknauss58/Lab-6-Group: This is a sparse package for a Stat 431 assignment.

test_that("simple linear regression by gradient descent is (approximately) correct", {

  my_result <- mtcars %>%
    slr_gd(mpg, hp)

  mtcars2 <- mtcars %>%
    mutate_all(scale)

  mass_result <- lm(mpg ~ hp, data = mtcars2)


  expect_equal(coef(mass_result)[['hp']], my_result$hp,
               tolerance = 0.05, scale = abs(my_result$hp))
  expect_equal(coef(mass_result)[[1]], my_result$Intercept,
               tolerance = 0.05, scale = abs(my_result$Intercept))

})


test_that("multiple linear regression by gradient descent is correct", {

  my_result <- mtcars %>%
    dplyr::select(mpg, hp, cyl) %>%
    mlr_gd(mpg)

  mtcars2 <- mtcars %>%
    mutate_all(scale)

  mass_result <- lm(mpg ~ hp + cyl, data = mtcars2)


  expect_equal(coef(mass_result)[['hp']], my_result$hp,
               tolerance = 0.05, scale = abs(my_result$hp))
  expect_equal(coef(mass_result)[['cyl']], my_result$cyl,
               tolerance = 0.05, scale = abs(my_result$cyl))
  expect_equal(coef(mass_result)[[1]], my_result$Intercept,
               tolerance = 0.05, scale = abs(my_result$Intercept))


})


test_that("multiple linear regression by matrix decomposition is correct", {

  my_result <- mtcars %>%
    dplyr::select(mpg, hp, cyl) %>%
    mlr_qr(mpg)

  mass_result <- lm(mpg ~ hp + cyl, data = mtcars)

  expect_equal(coef(mass_result)[['hp']], my_result$hp,
               tolerance = 0.05, scale = abs(my_result$hp))
  expect_equal(coef(mass_result)[['cyl']], my_result$cyl,
               tolerance = 0.05, scale = abs(my_result$cyl))
  expect_equal(coef(mass_result)[[1]], my_result$Intercept,
               tolerance = 0.05, scale = abs(my_result$Intercept))


})