tests/testthat/test-trajectory.R

In metR: Tools for Easier Analysis of Meteorological Fields

data("geopotential")

geopotential[, c("u", "v") := GeostrophicWind(gh, lon, lat), by = date]
geopotential[, `:=`(dlon = dlon(u, lat), dlat = dlat(v))]

test_that("trajectory works", {
  expect_known_value(
    Trajectory(
      dlon + dlat ~ lon + lat + date,
      x0 = 180,
      y0 = -60,
      data = na.omit(geopotential),
      res = 3,
      cyclical = c(TRUE, FALSE)
    ),
    "trajectory1"
  )

  expect_error(
    Trajectory(
      dlon ~ lon + lat + date,
      x0 = 180,
      y0 = -60,
      data = na.omit(geopotential)
    ),
    "LHS of formula must be of the form dx + dy",
    fixed = TRUE
  )

  expect_error(
    Trajectory(dlon + dlat ~ lat + date, x0 = 180, y0 = -60),
    "RHS of formula must be of the form x + y + t",
    fixed = TRUE
  )
})