tests/testthat/test-eof.R

In metR: Tools for Easier Analysis of Meteorological Fields

context("EOF")
data(geopotential)
test_that("EOF runs", {
  expect_s3_class(
    {
      EOF(gh ~ lat + lon | date, data = geopotential, n = 1)
    },
    "eof"
  )
})

test_that("EOF, returns correct PCs", {
  expect_equal(
    nrow(EOF(gh ~ lat + lon | date, data = geopotential, n = 2)$sdev),
    1
  )
})


test_that("EOF uses bootstrap", {
  expect_s3_class(
    {
      data(geopotential)
      EOF(gh ~ lat + lon | date, data = geopotential, n = 1, B = 10)
    },
    "eof"
  )
})


test_that("can use differnet engine", {
  set.seed(40)
  # with this seed, the base::svd result has a different sign.
  skip_if_not_installed("irlba")
  expect_equal(
    EOF(gh ~ lat + lon | date, data = geopotential, engine = base::svd)$left[,
      gh := -gh
    ][],
    EOF(gh ~ lat + lon | date, data = geopotential, n = 1)$left
  )
})

test_that("EOF works inside data.table", {
  expect_equal(
    geopotential[, EOF(gh ~ lon + lat | date)$left],
    EOF(gh ~ lon + lat | date, data = geopotential)$left
  )
})


test_that("EOF rotates", {
  expect_identical(
    round(
      EOF(
        gh ~ lon + lat | date,
        data = geopotential,
        n = 1:2,
        rotate = function(x) stats::varimax(x, normalize = FALSE)
      )$sdev$sd
    ),
    c(1424982, 542271)
  )

  expect_equal(
    EOF(
      gh ~ lon + lat | date,
      data = geopotential,
      n = 1:2,
      rotate = function(x) stats::varimax(x, normalize = FALSE)
    )$sdev$sd,
    expect_warning(
      EOF(
        gh ~ lon + lat | date,
        data = geopotential,
        n = 1:2,
        rotate = TRUE
      )$sdev$sd,
      "deprecated"
    )
  )
})


test_that("EOF fails gracefully", {
  expect_error(EOF(gh ~ lon + lat | date, data = geopotential, fill = "a"))
  expect_error(
    EOF(gh ~ lon1 + lat2 | date, data = geopotential),
    "Columns not found in data: lon1, lat2"
  )
  expect_error(
    EOF(gh ~ lon | date, data = geopotential),
    "The formula gh ~ lon | date  does not identify an unique observation for each cell."
  )
})

test_that("eof methods", {
  eof <- EOF(
    gh ~ lat + lon | date,
    data = geopotential,
    n = 1:5,
    engine = base::svd
  ) # need to force this engine so that predict is exact

  eof_12 <- cut(eof, 1:2)
  expect_s3_class(eof_12, "eof")
  expect_equal(as.character(unique(eof_12$left$PC)), c("PC1", "PC2"))
  expect_equal(as.character(unique(eof_12$right$PC)), c("PC1", "PC2"))
  expect_equal(as.character(unique(eof_12$sdev$PC)), c("PC1", "PC2"))

  expect_true(inherits(screeplot(eof), "gg"))
  expect_true(inherits(autoplot(eof), "gg"))

  eof_all <- EOF(
    gh ~ lat + lon | date,
    data = geopotential,
    n = NULL,
    engine = base::svd
  )
  expect_equal(
    geopotential[, .(lat, lon, date, gh)][order(lat, lon, date)],
    predict(eof_all)[order(lat, lon, date)]
  )

  expect_equal(predict(eof_all, n = 1:5), predict(eof))

  expect_known_output(summary(eof), file = "eof_summary")
})