tests/testthat/test-correlation.R

In cmu-delphi/epiprocess: Tools for basic signal processing in epidemiology

test_that("epi_cor throws an error for a non-epi_df for its first argument", {
  expect_error(epi_cor(1:10, 1, 1))
  expect_error(epi_cor(data.frame(x = 1:10), 1, 1))
})

test_that("epi_cor requires two var arguments, var1 and var2", {
  expect_error(epi_cor(archive_cases_dv_subset$DT, var2 = 1))
  expect_error(epi_cor(archive_cases_dv_subset$DT, var1 = 1))
})

test_that("epi_cor functions as intended", {
  expect_equal(
    epi_cor(
      x = cases_deaths_subset,
      var1 = case_rate_7d_av,
      var2 = death_rate_7d_av,
      cor_by = geo_value,
      dt1 = -2
    )[1],
    tibble(geo_value = unique(cases_deaths_subset$geo_value))
  )

  edf <- as_epi_df(data.frame(
    geo_value = rep("ak", 20),
    time_value = as.Date("2020-01-01") + 1:20,
    pos = 1:20,
    neg = -(1:20)
  ))
  expect_equal(epi_cor(edf, pos, pos)[[2]], 1)
  expect_equal(epi_cor(edf, pos, neg)[[2]], -1)
})

test_that("shift works as intended", {
  expect_identical(epiprocess:::shift(1:100, 1), dplyr::lead(1:100))
  expect_identical(epiprocess:::shift(1:100, 0), 1:100)
  expect_identical(epiprocess:::shift(1:100, -1), dplyr::lag(1:100))
})