tests/testthat/test-changepoint.R

In ggfortify: Data Visualization Tools for Statistical Analysis Results

context('test changepoint')

test_that('fortify.cpt works for AirPassengers', {
  skip_on_cran()
  skip_on_travis()
  skip_if_not_installed("changepoint")
  library(changepoint)
  # mean
  result <- changepoint::cpt.mean(AirPassengers)

  p <- ggplot2::autoplot(result)
  expect_true(is(p, 'ggplot'))

  fortified <- ggplot2::fortify(result)
  expect_equal(is.data.frame(fortified), TRUE)
  expect_equal(names(fortified), c('Index', 'Data', 'mean'))
  expect_equal(fortified$Index[1], as.Date('1949-01-01'))
  expect_equal(fortified$Index[nrow(fortified)], as.Date('1960-12-01'))

  filtered <- dplyr::filter(fortified, !is.na(mean))
  expect_equal(filtered$Index[1], as.Date('1955-05-01'))
  expect_equal(filtered$Index[nrow(filtered)], as.Date('1960-12-01'))

  # var
  fortified <- ggplot2::fortify(changepoint::cpt.var(AirPassengers))
  expect_equal(is.data.frame(fortified), TRUE)
  expect_equal(names(fortified), c('Index', 'Data', 'mean', 'variance'))
  expect_equal(fortified$Index[1], as.Date('1949-01-01'))
  expect_equal(fortified$Index[nrow(fortified)], as.Date('1960-12-01'))

  filtered <- dplyr::filter(fortified, !is.na(variance))
  expect_equal(filtered$Index[1], as.Date('1960-12-01'))
  expect_equal(filtered$Index[nrow(filtered)], as.Date('1960-12-01'))

  # meanvar
  fortified <- ggplot2::fortify(changepoint::cpt.meanvar(AirPassengers))
  expect_equal(is.data.frame(fortified), TRUE)
  expect_equal(names(fortified), c('Index', 'Data', 'mean', 'variance'))
  expect_equal(fortified$Index[1], as.Date('1949-01-01'))
  expect_equal(fortified$Index[nrow(fortified)], as.Date('1960-12-01'))

  filtered <- dplyr::filter(fortified, !is.na(mean) | !is.na(variance))
  expect_equal(filtered$Index[1], as.Date('1955-05-01'))
  expect_equal(filtered$Index[nrow(filtered)], as.Date('1960-12-01'))
})


test_that('fortify.breakpoints works for Nile', {
  skip_on_cran()
  skip_on_travis()
  skip_if_not_installed("strucchange")
  library(strucchange)
  bp.nile <- strucchange::breakpoints(Nile ~ 1)
  p <- ggplot2::autoplot(breakpoints(bp.nile, breaks = 2), data = Nile)
  expect_true(is(p, 'ggplot'))

  fortified <- ggplot2::fortify(bp.nile, is.date = TRUE)
  expect_equal(is.data.frame(fortified), TRUE)
  expect_equal(names(fortified), c('Index', 'Data', 'Breaks'))
  expect_equal(fortified$Index[1], as.Date('1871-01-01'))
  expect_equal(fortified$Index[nrow(fortified)], as.Date('1970-01-01'))

  filtered <- dplyr::filter(fortified, !is.na(Breaks))
  expect_equal(filtered$Index[1], as.Date('1898-01-01'))

  bp.pts <- strucchange::breakpoints(bp.nile, breaks = 2)
  fortified <- ggplot2::fortify(bp.pts, is.date = TRUE)
  expect_equal(is.data.frame(fortified), TRUE)
  expect_equal(names(fortified), c('Index', 'Breaks'))
  expect_equal(fortified$Index[1], as.Date('1871-01-01'))
  expect_equal(fortified$Index[nrow(fortified)], as.Date('1970-01-01'))

  filtered <- dplyr::filter(fortified, !is.na(Breaks))
  expect_equal(filtered$Index[1], as.Date('1898-01-01'))
  expect_equal(filtered$Index[nrow(filtered)], as.Date('1953-01-01'))

  fortified <- ggplot2::fortify(bp.pts, data = Nile, is.date = TRUE)
  expect_equal(is.data.frame(fortified), TRUE)
  expect_equal(names(fortified), c('Index', 'Data', 'Breaks'))
  expect_equal(fortified$Index[1], as.Date('1871-01-01'))
  expect_equal(fortified$Index[nrow(fortified)], as.Date('1970-01-01'))
})