Graticule layer

The viz_graticule function draws a graticule (latitude and longitude lines) on the map. The spacing between lines can be uniform or specified separately for parallels and meridians.

Usage

viz_graticule(
  map,
  id = NULL,
  step = 10,
  stroke = "#9ad5e6",
  fill = "none",
  strokeWidth = 0.8,
  strokeLinecap = "square",
  strokeLinejoin = "round",
  strokeDasharray = 2,
  ...
)

Arguments

map

A geovizr map object created using viz_create().

id

character. Optional. Unique layer id.

step

numeric or vector. Optional. Gap between graticules (default 10). Can be a single value or a vector of two values (e.g. c(10, 20)).

stroke

character. Optional. Stroke color (default "#9ad5e6").

fill

character. Optional. Fill color (default "none").

strokeWidth

numeric. Optional. Stroke width (default 0.8).

strokeLinecap

character. Optional. Stroke line cap (default "square").

strokeLinejoin

character. Optional. Stroke line join (default "round").

strokeDasharray

numeric or vector. Optional. Stroke dash pattern (default 2).

...

Additional SVG attributes (e.g. opacity, etc.).

Value

A modified `geoviz` map object with a new layer added. Rendering is performed using viz_render().

Examples

library(sf)
world <- st_read(
  system.file("gpkg/world.gpkg", package = "geovizr"),
  quiet = TRUE
)

viz_create(projection = "EqualEarth", background = "white") |>
  viz_path(datum = world, fill = "#f1f3f5") |>
  viz_graticule(step = c(10, 20), stroke = "#38896F") |>
  viz_render()