tests/testthat/test-median_center.R

In centr: Weighted and Unweighted Spatial Centers

test_that("euclidean planar distance", {
  expect_equal(euclid_xy_dist(2, 2, 0, 0), 2 * sqrt(2))
  expect_equal(euclid_xy_dist(c(3, 5), c(4, 12), c(0, 0), c(0, 0)), c(5, 13))
})

test_that("median_center", {
  "projected; checked with ArcGIS Pro"
  df_triangle <- data.frame(
    lon = c(-99, -110, -70),
    lat = c(20, 40, 30)
  )
  x_triangle <- sf::st_as_sf(df_triangle, coords = c("lon", "lat"), crs = 4326)
  x_triangle_proj <- sf::st_transform(x_triangle, crs = "ESRI:102003")

  expect_equal(
    sf::st_coordinates(sf::st_transform(median_center(x_triangle_proj), 4326)),
    as.matrix(data.frame(X = -96.0135231, Y = 28.6822725)),
    tolerance = 0.0001
  )

  df_rand <- data.frame(
    lon = c(
      -70,
      -80,
      -123,
      -79,
      -90,
      -121,
      -68,
      -93,
      -78,
      -108,
      -113,
      -94,
      -114
    ),
    lat = c(45, 36, 44, 48, 34, 48, 27, 27, 29, 33, 48, 26, 36)
  )
  x_rand <- sf::st_as_sf(df_rand, coords = c("lon", "lat"), crs = 4326)
  x_rand_proj <- sf::st_transform(x_rand, crs = "ESRI:102003")
  expect_equal(
    sf::st_coordinates(sf::st_transform(median_center(x_rand_proj), 4326)),
    as.matrix(data.frame(X = -91.2887347, Y = 35.3991316)),
    tolerance = 0.0001
  )

  expect_equal(
    sf::st_coordinates(sf::st_transform(median_center(x_proj), 4326)),
    as.matrix(data.frame(X = -96.4593993, Y = 38.0191323)),
    tolerance = 0.0001
  )
})

test_that("column not named geometry should still work", {
  x_geom_col_proj <- x_proj
  colnames(x_geom_col_proj)[colnames(x_geom_col_proj) == "geometry"] <- "geom"
  sf::st_geometry(x_geom_col_proj) <- "geom"

  "projected"
  expect_equal(
    colnames(median_center(x_geom_col_proj, group = "grp", weight = "wts")),
    c("grp", "geometry")
  )
})