tests/testthat/test-negbin.R

In insight: Easy Access to Model Information for Various Model Objects

skip_if_not_installed("aod")

data(dja, package = "aod")
m1 <- suppressWarnings(
  aod::negbin(y ~ group + offset(log(trisk)),
    random = ~village,
    data = dja
  )
)

test_that("model_info", {
  expect_true(model_info(m1)$is_negbin)
  expect_true(model_info(m1)$is_mixed)
  expect_false(model_info(m1)$is_linear)
})

test_that("find_predictors", {
  expect_identical(find_predictors(m1), list(conditional = c("group", "trisk")))
  expect_identical(find_predictors(m1, flatten = TRUE), c("group", "trisk"))
  expect_identical(
    find_predictors(m1, effects = "random"),
    list(random = "village")
  )
  expect_identical(
    find_predictors(m1, effects = "all"),
    list(
      conditional = c("group", "trisk"),
      random = "village"
    )
  )
})

test_that("get_df", {
  expect_equal(
    get_df(m1, type = "residual"),
    aod::df.residual(m1),
    ignore_attr = TRUE
  )
  expect_equal(
    get_df(m1, type = "normal"),
    Inf,
    ignore_attr = TRUE
  )
  expect_equal(
    get_df(m1, type = "wald"),
    Inf,
    ignore_attr = TRUE
  )
})

test_that("find_random", {
  expect_identical(find_random(m1), list(random = "village"))
})

test_that("get_random", {
  expect_equal(get_random(m1), dja[, "village", drop = FALSE], ignore_attr = TRUE)
})

test_that("find_response", {
  expect_identical(find_response(m1), "y")
  expect_identical(find_response(m1, combine = FALSE), "y")
})

test_that("get_response", {
  expect_equal(get_response(m1), dja[, "y"])
})

test_that("get_predictors", {
  expect_equal(colnames(get_predictors(m1)), c("group", "trisk"))
})

test_that("link_inverse", {
  expect_equal(link_inverse(m1)(0.2), exp(0.2), tolerance = 1e-5)
})

test_that("link_function", {
  expect_equal(link_function(m1)(0.2), log(0.2), tolerance = 1e-5)
})

test_that("get_data", {
  expect_equal(nrow(get_data(m1, verbose = FALSE)), 75)
  expect_equal(colnames(get_data(m1, verbose = FALSE)), c("y", "group", "trisk", "village"))
})

test_that("find_formula", {
  expect_length(find_formula(m1), 2)
  expect_equal(
    find_formula(m1),
    list(
      conditional = as.formula("y ~ group + offset(log(trisk))"),
      random = as.formula("~village")
    ),
    ignore_attr = TRUE
  )
})

test_that("find_variables", {
  expect_equal(
    find_variables(m1),
    list(
      response = "y",
      conditional = c("group", "trisk"),
      random = "village"
    )
  )
  expect_equal(
    find_variables(m1, flatten = TRUE),
    c("y", "group", "trisk", "village")
  )
})

test_that("n_obs", {
  expect_equal(n_obs(m1), 75)
})

test_that("find_parameters", {
  expect_equal(
    find_parameters(m1),
    list(
      conditional = c("(Intercept)", "groupTREAT"),
      random = c(
        "phi.villageBAK",
        "phi.villageBAM",
        "phi.villageBAN",
        "phi.villageBIJ",
        "phi.villageBOU",
        "phi.villageBYD",
        "phi.villageDEM",
        "phi.villageDIA",
        "phi.villageHAM",
        "phi.villageLAM",
        "phi.villageLAY",
        "phi.villageMAF",
        "phi.villageMAH",
        "phi.villageMAK",
        "phi.villageMED",
        "phi.villageNAB",
        "phi.villageSAG",
        "phi.villageSAM",
        "phi.villageSOU"
      )
    )
  )
  expect_equal(nrow(get_parameters(m1)), 2)
  expect_equal(
    get_parameters(m1)$Parameter,
    c("(Intercept)", "groupTREAT")
  )
})

test_that("is_multivariate", {
  expect_false(is_multivariate(m1))
})

test_that("find_terms", {
  expect_equal(
    find_terms(m1),
    list(
      response = "y",
      conditional = c("group", "offset(log(trisk))"),
      random = "village"
    )
  )
})

test_that("find_algorithm", {
  expect_equal(find_algorithm(m1), list(algorithm = "ML"))
})

test_that("find_statistic", {
  expect_identical(find_statistic(m1), "z-statistic")
})