inst/tinytest/test-webmercator.R

In sgo: Simple Geographical Operations (with OSGB36)

#http://epsg.io/transform#s_srs=4326&t_srs=3857
### Convert from WGS84 to Pseudo-Mercator ###
# Check inputs
expect_error(sgo_wgs84_en(sgo_points(list(3487823.234, -305433.201,
                                          5313739.634), epsg=4936)),
             "only supports WGS84 or ETRS89 polar entries")
expect_error(sgo_wgs84_en(sgo_points(list(18.5, 54.2), epsg=4326), to=4936),
             fixed = TRUE,
  "This routine only supports converting to EPSG:3857 (Pseudo-Mercator)")

expect_true(all(abs(sgo_coordinates(sgo_wgs84_en(
  sgo_points(list(18.5, 54.2), epsg=4326))) -
    c(2059410.5797, 7208125.2609)) < c(0.0001, 0.0001)))
expect_true(all(abs(sgo_coordinates(sgo_wgs84_en(
  sgo_points(list(113.4, 46.78), epsg=4326))) -
    c(12623630.2560, 5906238.1135)) < c(0.0001, 0.0001)))
expect_true(all(abs(sgo_coordinates(sgo_wgs84_en(
  sgo_points(list(16.9, 67.8), epsg=4326))) -
    c(1881299.3944, 10387819.7211)) < c(0.0001, 0.0001)))

#3D input
expect_true(all(abs(sgo_coordinates(sgo_wgs84_en(
  sgo_points(list(18.5, 54.2, 47), epsg=4979))) -
    c(2059410.5797, 7208125.2609)) < c(0.0001, 0.0001)))

# Additional elements
ln <- c(-4.22472, -2.09908)
lt <- c(57.47777, 57.14965)
N <- c("Inverness", "Aberdeen")
country <- c("Scotland", "Scotland")
df <- data.frame(N, ln, lt, country, stringsAsFactors = FALSE)
p1 <- sgo_wgs84_en(sgo_points(df, coords=c("ln", "lt"), epsg=4326))
e <- c(-470293.6791, -233668.5167)
n <- c(7858404.2287, 7790767.5442)
df2 <- data.frame(N, country, e, n, stringsAsFactors = FALSE)
p2 <- sgo_points(df2, coords=c("e", "n"), epsg=3857)
expect_true(all(abs(as.data.frame(p1[1:2]) -
                      as.data.frame(p2[1:2])) < 0.0001))
expect_equal(as.data.frame(p1[3:4]), as.data.frame(p2[3:4]))


#http://epsg.io/transform#s_srs=3857&t_srs=4326
### Convert from Pseudo-Mercator to WGS84 ###
# Check inputs
expect_error(sgo_en_wgs84(sgo_points(list(18.5, 54.2), epsg=4326)),
             fixed = TRUE,
             "This routine only supports EPSG:3857 entries")
expect_error(sgo_en_wgs84(sgo_points(list(-533224.71, 8030168.44),
                                     epsg=3857), to=4258),
             fixed = TRUE,
             "This routine only supports converting to EPSG:4326")

expect_true(all(abs(sgo_coordinates(sgo_transform(
  sgo_points(list(-489196.98, 7504281.69), epsg=3857), to=4326))
  - c(-4.394531241, 55.727110090)) < 0.000000001))
expect_true(all(abs(sgo_coordinates(sgo_transform(
  sgo_points(list(-533224.71, 8030168.44), epsg=3857), to=4326))
  - c(-4.790039069, 58.297944029)) < 0.000000001))
expect_true(all(abs(sgo_coordinates(sgo_transform(
  sgo_points(list(-841418.81, 7602121.08), epsg=3857), to=4326))
  - c(-7.558593774, 56.218923164)) < 0.000000001))

# Additional elements
e <- c(-470293.68, -233668.52)
n <- c(7858404.23, 7790767.54)
N <- c("Inverness", "Aberdeen")
country <- c("Scotland", "Scotland")
df <- data.frame(N, e, n, country, stringsAsFactors = FALSE)
p1 <- sgo_en_wgs84(sgo_points(df, coords=c("e", "n"), epsg=3857))
ln <- c(-4.22472, -2.09908)
lt <- c(57.47777, 57.14965)
df2 <- data.frame(N, country, ln, lt, stringsAsFactors = FALSE)
p2 <- sgo_points(df2, coords=c("ln", "lt"), epsg=4326)
expect_true(all(abs(as.data.frame(p1[1:2]) - as.data.frame(p2[1:2])) <
                  0.000001))
expect_equal(as.data.frame(p1[3:4]), as.data.frame(p2[3:4]))