Add example data

NAMESPACE

@@ -347,6 +347,7 @@ export(wk_drop_m)
 export(wk_drop_z)
 export(wk_envelope)
 export(wk_envelope_handler)
+export(wk_example)
 export(wk_flatten)
 export(wk_flatten_filter)
 export(wk_format)

NEWS.md

@@ -24,6 +24,8 @@
   (#139, #153).
 * The `xy_writer()` now opportunistically avoids allocating vectors for Z
   or M values unless they are actually needed (#131, #154).
+* Added example WKT for all geometry types and dimensions plus helper
+  `wk_example()` to access them and set various properties (#155).
 
 # wk 0.6.0
 

R/data.R

@@ -13,3 +13,38 @@
 
 #' @rdname wk_proj_crs_view
 "wk_proj_crs_json"
+
+#' Create example geometry objects
+#'
+#' @param which An example name. Valid example names are
+#'   - "nc"
+#'   - "point", "linestring", "polygon", "multipoint",
+#'     "multilinestring", "multipolygon", "geometrycollection"
+#'   - One of the above with the "_z", "_m", or "_zm" suffix.
+#' @inheritParams wk_crs
+#' @inheritParams wk_is_geodesic
+#'
+#' @return A [wkt()] with the specified example.
+#' @export
+#'
+#' @examples
+#' wk_example("polygon")
+#'
+wk_example <- function(which = "nc",
+                       crs = NA,
+                       geodesic = FALSE) {
+  all_examples <- wk::wk_example_wkt
+  match.arg(which, names(all_examples))
+
+  handleable <- all_examples[[which]]
+
+  if (!identical(crs, NA)) {
+    wk::wk_crs(handleable) <- crs
+  }
+
+  wk::wk_is_geodesic(handleable) <- geodesic
+  handleable
+}
+
+#' @rdname wk_example
+"wk_example_wkt"

R/plot.R

@@ -134,6 +134,10 @@ wk_plot_point_or_multipoint <- function(x, dots) {
 
 wk_plot_line_or_multiline <- function(x, dots) {
   coords <- wk_coords(x)
+  if (nrow(coords) == 0) {
+    return()
+  }
+
   geom_id <- coords$part_id
   geom_id_lag <- c(-1L, geom_id[-length(geom_id)])
   new_geom <- geom_id != geom_id_lag
@@ -152,6 +156,9 @@ wk_plot_line_or_multiline <- function(x, dots) {
 
 wk_plot_poly_or_multi_poly <- function(x, dots) {
   coords <- wk_coords(x)
+  if (nrow(coords) == 0) {
+    return()
+  }
 
   # for polygons we can use the coord vectors directly
   # because the graphics device expects open loops

data-raw/example_wkt.R

@@ -0,0 +1,164 @@
+
+nc_wkt <- wk::as_wkt(sf::read_sf(system.file("shape/nc.shp", package = "sf")))
+wk::wk_crs(nc_wkt) <- wk::wk_crs_projjson(wk::wk_crs(nc_wkt))
+
+wk_example_wkt <- list(
+  nc = nc_wkt,
+  point = c("POINT (30 10)", "POINT EMPTY", NA),
+  linestring = c(
+    "LINESTRING (30 10, 10 30, 40 40)", "LINESTRING EMPTY",
+    NA
+  ),
+  polygon = c(
+    "POLYGON ((30 10, 40 40, 20 40, 10 20, 30 10))",
+    "POLYGON ((35 10, 45 45, 15 40, 10 20, 35 10), (20 30, 35 35, 30 20, 20 30))",
+    "POLYGON EMPTY", NA
+  ),
+  multipoint = c(
+    "MULTIPOINT ((30 10))",
+    "MULTIPOINT ((10 40), (40 30), (20 20), (30 10))", "MULTIPOINT ((10 40), (40 30), (20 20), (30 10))",
+    "MULTIPOINT EMPTY", NA
+  ),
+  multilinestring = c(
+    "MULTILINESTRING ((30 10, 10 30, 40 40))",
+    "MULTILINESTRING ((10 10, 20 20, 10 40), (40 40, 30 30, 40 20, 30 10))",
+    "MULTILINESTRING EMPTY", NA
+  ),
+  multipolygon = c(
+    "MULTIPOLYGON (((30 10, 40 40, 20 40, 10 20, 30 10)))",
+    "MULTIPOLYGON (((30 20, 45 40, 10 40, 30 20)), ((15 5, 40 10, 10 20, 5 10, 15 5)))",
+    "MULTIPOLYGON (((40 40, 20 45, 45 30, 40 40)), ((20 35, 10 30, 10 10, 30 5, 45 20, 20 35), (30 20, 20 15, 20 25, 30 20)))",
+    "MULTIPOLYGON EMPTY", NA
+  ),
+  geometrycollection = c(
+    "GEOMETRYCOLLECTION (POINT (30 10))",
+    "GEOMETRYCOLLECTION (LINESTRING (30 10, 10 30, 40 40))", "GEOMETRYCOLLECTION (POLYGON ((30 10, 40 40, 20 40, 10 20, 30 10)))",
+    "GEOMETRYCOLLECTION (POINT (30 10), LINESTRING (30 10, 10 30, 40 40), POLYGON ((30 10, 40 40, 20 40, 10 20, 30 10)))",
+    "GEOMETRYCOLLECTION (GEOMETRYCOLLECTION (POINT (30 10)))", "GEOMETRYCOLLECTION (GEOMETRYCOLLECTION (LINESTRING (30 10, 10 30, 40 40)))",
+    "GEOMETRYCOLLECTION (GEOMETRYCOLLECTION (POLYGON ((30 10, 40 40, 20 40, 10 20, 30 10))))",
+    "GEOMETRYCOLLECTION EMPTY", NA
+  ),
+  point_z = c(
+    "POINT Z (30 10 40)",
+    "POINT Z EMPTY", NA
+  ),
+  linestring_z = c(
+    "LINESTRING Z (30 10 40, 10 30 40, 40 40 80)",
+    "LINESTRING Z EMPTY", NA
+  ),
+  polygon_z = c(
+    "POLYGON Z ((30 10 40, 40 40 80, 20 40 60, 10 20 30, 30 10 40))",
+    "POLYGON Z ((35 10 45, 45 45 90, 15 40 55, 10 20 30, 35 10 45), (20 30 50, 35 35 70, 30 20 50, 20 30 50))",
+    "POLYGON Z EMPTY", NA
+  ),
+  multipoint_z = c(
+    "MULTIPOINT Z ((30 10 40))",
+    "MULTIPOINT Z ((10 40 50), (40 30 70), (20 20 40), (30 10 40))",
+    "MULTIPOINT Z ((10 40 50), (40 30 70), (20 20 40), (30 10 40))",
+    "MULTIPOINT Z EMPTY", NA
+  ),
+  multilinestring_z = c(
+    "MULTILINESTRING Z ((30 10 40, 10 30 40, 40 40 80))",
+    "MULTILINESTRING Z ((10 10 20, 20 20 40, 10 40 50), (40 40 80, 30 30 60, 40 20 60, 30 10 40))",
+    "MULTILINESTRING Z EMPTY", NA
+  ),
+  multipolygon_z = c(
+    "MULTIPOLYGON Z (((30 10 40, 40 40 80, 20 40 60, 10 20 30, 30 10 40)))",
+    "MULTIPOLYGON Z (((30 20 50, 45 40 85, 10 40 50, 30 20 50)), ((15 5 20, 40 10 50, 10 20 30, 5 10 15, 15 5 20)))",
+    "MULTIPOLYGON Z (((40 40 80, 20 45 65, 45 30 75, 40 40 80)), ((20 35 55, 10 30 40, 10 10 20, 30 5 35, 45 20 65, 20 35 55), (30 20 50, 20 15 35, 20 25 45, 30 20 50)))",
+    "MULTIPOLYGON Z EMPTY", NA
+  ),
+  geometrycollection_z = c(
+    "GEOMETRYCOLLECTION Z (POINT Z (30 10 40))",
+    "GEOMETRYCOLLECTION Z (LINESTRING Z (30 10 40, 10 30 40, 40 40 80))",
+    "GEOMETRYCOLLECTION Z (POLYGON Z ((30 10 40, 40 40 80, 20 40 60, 10 20 30, 30 10 40)))",
+    "GEOMETRYCOLLECTION Z (POINT Z (30 10 40), LINESTRING Z (30 10 40, 10 30 40, 40 40 80), POLYGON Z ((30 10 40, 40 40 80, 20 40 60, 10 20 30, 30 10 40)))",
+    "GEOMETRYCOLLECTION Z (GEOMETRYCOLLECTION Z (POINT Z (30 10 40)))",
+    "GEOMETRYCOLLECTION Z (GEOMETRYCOLLECTION Z (LINESTRING Z (30 10 40, 10 30 40, 40 40 80)))",
+    "GEOMETRYCOLLECTION Z (GEOMETRYCOLLECTION Z (POLYGON Z ((30 10 40, 40 40 80, 20 40 60, 10 20 30, 30 10 40))))",
+    "GEOMETRYCOLLECTION Z EMPTY", NA
+  ),
+  point_m = c(
+    "POINT M (30 10 300)",
+    "POINT M EMPTY", NA
+  ), linestring_m = c(
+    "LINESTRING M (30 10 300, 10 30 300, 40 40 1600)",
+    "LINESTRING M EMPTY", NA
+  ),
+  polygon_m = c(
+    "POLYGON M ((30 10 300, 40 40 1600, 20 40 800, 10 20 200, 30 10 300))",
+    "POLYGON M ((35 10 350, 45 45 2025, 15 40 600, 10 20 200, 35 10 350), (20 30 600, 35 35 1225, 30 20 600, 20 30 600))",
+    "POLYGON M EMPTY", NA
+  ),
+  multipoint_m = c(
+    "MULTIPOINT M ((30 10 300))",
+    "MULTIPOINT M ((10 40 400), (40 30 1200), (20 20 400), (30 10 300))",
+    "MULTIPOINT M ((10 40 400), (40 30 1200), (20 20 400), (30 10 300))",
+    "MULTIPOINT M EMPTY", NA
+  ),
+  multilinestring_m = c(
+    "MULTILINESTRING M ((30 10 300, 10 30 300, 40 40 1600))",
+    "MULTILINESTRING M ((10 10 100, 20 20 400, 10 40 400), (40 40 1600, 30 30 900, 40 20 800, 30 10 300))",
+    "MULTILINESTRING M EMPTY", NA
+  ),
+  multipolygon_m = c(
+    "MULTIPOLYGON M (((30 10 300, 40 40 1600, 20 40 800, 10 20 200, 30 10 300)))",
+    "MULTIPOLYGON M (((30 20 600, 45 40 1800, 10 40 400, 30 20 600)), ((15 5 75, 40 10 400, 10 20 200, 5 10 50, 15 5 75)))",
+    "MULTIPOLYGON M (((40 40 1600, 20 45 900, 45 30 1350, 40 40 1600)), ((20 35 700, 10 30 300, 10 10 100, 30 5 150, 45 20 900, 20 35 700), (30 20 600, 20 15 300, 20 25 500, 30 20 600)))",
+    "MULTIPOLYGON M EMPTY", NA
+  ),
+  geometrycollection_m = c(
+    "GEOMETRYCOLLECTION M (POINT M (30 10 300))",
+    "GEOMETRYCOLLECTION M (LINESTRING M (30 10 300, 10 30 300, 40 40 1600))",
+    "GEOMETRYCOLLECTION M (POLYGON M ((30 10 300, 40 40 1600, 20 40 800, 10 20 200, 30 10 300)))",
+    "GEOMETRYCOLLECTION M (POINT M (30 10 300), LINESTRING M (30 10 300, 10 30 300, 40 40 1600), POLYGON M ((30 10 300, 40 40 1600, 20 40 800, 10 20 200, 30 10 300)))",
+    "GEOMETRYCOLLECTION M (GEOMETRYCOLLECTION M (POINT M (30 10 300)))",
+    "GEOMETRYCOLLECTION M (GEOMETRYCOLLECTION M (LINESTRING M (30 10 300, 10 30 300, 40 40 1600)))",
+    "GEOMETRYCOLLECTION M (GEOMETRYCOLLECTION M (POLYGON M ((30 10 300, 40 40 1600, 20 40 800, 10 20 200, 30 10 300))))",
+    "GEOMETRYCOLLECTION M EMPTY", NA
+  ),
+  point_zm = c(
+    "POINT ZM (30 10 40 300)",
+    "POINT ZM EMPTY", NA
+  ),
+  linestring_zm = c(
+    "LINESTRING ZM (30 10 40 300, 10 30 40 300, 40 40 80 1600)",
+    "LINESTRING ZM EMPTY", NA
+  ),
+  polygon_zm = c(
+    "POLYGON ZM ((30 10 40 300, 40 40 80 1600, 20 40 60 800, 10 20 30 200, 30 10 40 300))",
+    "POLYGON ZM ((35 10 45 350, 45 45 90 2025, 15 40 55 600, 10 20 30 200, 35 10 45 350), (20 30 50 600, 35 35 70 1225, 30 20 50 600, 20 30 50 600))",
+    "POLYGON ZM EMPTY", NA
+  ),
+  multipoint_zm = c(
+    "MULTIPOINT ZM ((30 10 40 300))",
+    "MULTIPOINT ZM ((10 40 50 400), (40 30 70 1200), (20 20 40 400), (30 10 40 300))",
+    "MULTIPOINT ZM ((10 40 50 400), (40 30 70 1200), (20 20 40 400), (30 10 40 300))",
+    "MULTIPOINT ZM EMPTY", NA
+  ),
+  multilinestring_zm = c(
+    "MULTILINESTRING ZM ((30 10 40 300, 10 30 40 300, 40 40 80 1600))",
+    "MULTILINESTRING ZM ((10 10 20 100, 20 20 40 400, 10 40 50 400), (40 40 80 1600, 30 30 60 900, 40 20 60 800, 30 10 40 300))",
+    "MULTILINESTRING ZM EMPTY", NA
+  ),
+  multipolygon_zm = c(
+    "MULTIPOLYGON ZM (((30 10 40 300, 40 40 80 1600, 20 40 60 800, 10 20 30 200, 30 10 40 300)))",
+    "MULTIPOLYGON ZM (((30 20 50 600, 45 40 85 1800, 10 40 50 400, 30 20 50 600)), ((15 5 20 75, 40 10 50 400, 10 20 30 200, 5 10 15 50, 15 5 20 75)))",
+    "MULTIPOLYGON ZM (((40 40 80 1600, 20 45 65 900, 45 30 75 1350, 40 40 80 1600)), ((20 35 55 700, 10 30 40 300, 10 10 20 100, 30 5 35 150, 45 20 65 900, 20 35 55 700), (30 20 50 600, 20 15 35 300, 20 25 45 500, 30 20 50 600)))",
+    "MULTIPOLYGON ZM EMPTY", NA
+  ),
+  geometrycollection_zm = c(
+    "GEOMETRYCOLLECTION ZM (POINT ZM (30 10 40 300))",
+    "GEOMETRYCOLLECTION ZM (LINESTRING ZM (30 10 40 300, 10 30 40 300, 40 40 80 1600))",
+    "GEOMETRYCOLLECTION ZM (POLYGON ZM ((30 10 40 300, 40 40 80 1600, 20 40 60 800, 10 20 30 200, 30 10 40 300)))",
+    "GEOMETRYCOLLECTION ZM (POINT ZM (30 10 40 300), LINESTRING ZM (30 10 40 300, 10 30 40 300, 40 40 80 1600), POLYGON ZM ((30 10 40 300, 40 40 80 1600, 20 40 60 800, 10 20 30 200, 30 10 40 300)))",
+    "GEOMETRYCOLLECTION ZM (GEOMETRYCOLLECTION ZM (POINT ZM (30 10 40 300)))",
+    "GEOMETRYCOLLECTION ZM (GEOMETRYCOLLECTION ZM (LINESTRING ZM (30 10 40 300, 10 30 40 300, 40 40 80 1600)))",
+    "GEOMETRYCOLLECTION ZM (GEOMETRYCOLLECTION ZM (POLYGON ZM ((30 10 40 300, 40 40 80 1600, 20 40 60 800, 10 20 30 200, 30 10 40 300))))",
+    "GEOMETRYCOLLECTION ZM EMPTY", NA
+  )
+)
+
+wk_example_wkt <- lapply(wk_example_wkt, wk::as_wkt)
+
+usethis::use_data(wk_example_wkt, overwrite = TRUE)

tests/testthat/test-data.R

@@ -0,0 +1,18 @@
+
+test_that("all examples can be created with default arguments", {
+  for (which in names(wk::wk_example_wkt)) {
+    expect_s3_class(wk_example(!! which), "wk_wkt")
+  }
+})
+
+test_that("requested example crs is respected", {
+  expect_identical(
+    wk::wk_crs(wk_example(crs = "EPSG:1234")),
+    "EPSG:1234"
+  )
+})
+
+test_that("requested example edges field is respected", {
+  spherical <- wk_example(geodesic = TRUE)
+  expect_true(wk::wk_is_geodesic(spherical))
+})

tests/testthat/test-plot.R

@@ -60,3 +60,9 @@ test_that("xy and rect plot methods work", {
 test_that("crc plot method works", {
   expect_identical(plot(crc(1, 2, 3)), crc(1, 2, 3))
 })
+
+test_that("plot can plot all examples", {
+  for (which in names(wk_example_wkt)) {
+    expect_silent(wk_plot(wk_example_wkt[[!!which]], xlab = which))
+  }
+})

tests/testthat/test-sfc-writer.R

@@ -434,3 +434,14 @@ test_that("sfc_writer() propagates precision", {
   sf::st_precision(sfc_prec) <- 0.01
   expect_identical(sf::st_precision(wk_handle(sfc_prec, sfc_writer())), 0.01)
 })
+
+test_that("sfc_writer() can roundtrip examples", {
+  skip_if_not_installed("sf")
+
+  for (which in names(wk_example_wkt)) {
+    expect_identical(
+      wk_handle(sf::st_as_sfc(wk_example(!!which, crs = NULL)), sfc_writer()),
+      sf::st_as_sfc(wk_example(!!which, crs = NULL))
+    )
+  }
+})

tests/testthat/test-wkb.R

@@ -99,3 +99,12 @@ test_that("as_wkb() propagates geodesic", {
   expect_true(wk_is_geodesic(x))
   expect_true(wk_is_geodesic(as_wkb(wkt("POINT (1 2)", geodesic = TRUE))))
 })
+
+test_that("examples as wkb roundtrip", {
+  for (which in names(wk_example_wkt)) {
+    expect_identical(
+      wk_handle(as_wkb(wk_example(!!which, crs = NULL)), wkb_writer()),
+      as_wkb(wk_example(!!which, crs = NULL))
+    )
+  }
+})

tests/testthat/test-wkt.R

@@ -91,3 +91,12 @@ test_that("as_wkt() propagates geodesic", {
   expect_true(wk_is_geodesic(x))
   expect_true(wk_is_geodesic(as_wkt(as_wkb(wkt("POINT (1 2)", geodesic = TRUE)))))
 })
+
+test_that("examples as wkt roundtrip", {
+  for (which in names(wk_example_wkt)) {
+    expect_identical(
+      wk_handle(wk_example(!!which, crs = NULL), wkt_writer()),
+      wk_example(!!which, crs = NULL)
+    )
+  }
+})

tests/testthat/test-xy-writer.R

@@ -71,3 +71,26 @@ test_that("xy_writer() fills unused dimensions with NA", {
     )
   )
 })
+
+test_that("xy_writer() can roundtrip point examples", {
+  # NA point doesn't roundtrip
+  expect_identical(
+    wk_handle(wk_example_wkt$point, xy_writer()),
+    xy(c(30, NA, NA), c(10, NA, NA))
+  )
+
+  expect_identical(
+    wk_handle(wk_example_wkt$point_z, xy_writer()),
+    xyz(c(30, NA, NA), c(10, NA, NA), c(40, NA, NA))
+  )
+
+  expect_identical(
+    wk_handle(wk_example_wkt$point_m, xy_writer()),
+    xym(c(30, NA, NA), c(10, NA, NA), c(300, NA, NA))
+  )
+
+  expect_identical(
+    wk_handle(wk_example_wkt$point_zm, xy_writer()),
+    xyzm(c(30, NA, NA), c(10, NA, NA), c(40, NA, NA), c(300, NA, NA))
+  )
+})