Plot global-hex values with hierarchical level of detail

Source polygons are never constructed. The method selects a legitimate Z7 or Z3 ancestor level and aggregates source values before making any display geometry. render = "auto" draws smaller results as vector polygons and rasterizes larger results for a compact, device-friendly display.

Usage

# S3 method for class 'globalhex_data'
plot(
  x,
  y = NULL,
  value = NULL,
  resolution = NULL,
  max_cells = 100000L,
  fun = NULL,
  na.rm = TRUE,
  lod = TRUE,
  extent = NULL,
  xlim = NULL,
  ylim = NULL,
  device_size = NULL,
  cell_pixels = 3,
  crs = 4326,
  border = NA,
  pal = NULL,
  render = c("auto", "polygon", "raster"),
  raster_threshold = 20000L,
  ...
)

Arguments

x

A hex_data() object.

y

Unused; present for the base plot() generic.

value

Attribute column to plot. NULL uses the first attribute.

resolution

Explicit display resolution. NULL selects one automatically.

max_cells

Hard maximum number of display cells.

fun

Aggregation function. NULL uses type-aware defaults; use sum explicitly for counts.

na.rm

Whether aggregation removes missing values.

lod

Whether to use automatic hierarchical level of detail.

extent

Geographic display extent as c(xmin, xmax, ymin, ymax).

xlim, ylim

Optional conventional longitude and latitude limits. They override the corresponding part of extent and participate in LOD selection before projection.

device_size

Optional display width and height in pixels.

cell_pixels

Approximate minimum cell diameter in screen pixels.

crs

Display CRS understood by sf::st_crs(). Aggregation always happens before projection.

border

Polygon border passed to plot(). Raster rendering cannot draw individual cell borders.

pal

Optional color palette function or vector.

render

Rendering backend. "auto" rasterizes sufficiently large displays when terra is available, "polygon" always draws vector polygons, and "raster" always rasterizes the displayed polygons.

raster_threshold

Number of displayed cells at which automatic rendering switches to a raster. An explicit non-missing border keeps automatic rendering in polygon mode.

...

Additional arguments passed to the selected sf or terra plot method.

Value

The aggregated globalhex_data used for display, invisibly, with plot_resolution, plot_extent, and plot_render attributes. Polygon rendering also attaches the displayed geometry; raster rendering attaches plot_raster_size instead.

Examples

if (requireNamespace("sf", quietly = TRUE)) {
  cells <- point_to_cell(rbind(c(0, 0), c(10, 10)), 5)
  plot(hex_data(cells, value = c(1, 2)), max_cells = 1000)
}