Add a Geodesic Circle Layer (add_circles)

Drop-in equivalent of leaflet::addCircles(). Unlike add_points() (where radius is in screen pixels), add_circles() takes radius in meters on the ground and builds geodesic polygon rings triangulated in C++17.

Usage

add_circles(
  map,
  data = NULL,
  lon = NULL,
  lat = NULL,
  radius = 500,
  fill_color = "#38bdf8",
  palette = "viridis",
  fill_opacity = 0.65,
  stroke = TRUE,
  line_color = "#e2e8f0",
  line_width = 1,
  popup = NULL,
  label = NULL,
  n_segments = 24L,
  id = NULL,
  group = NULL,
  legend = TRUE
)

Arguments

map: A glmap widget or glmap_proxy.
data: An sf, sfc, or data.frame object.
lon: Optional longitude column name or formula (~lon).
lat: Optional latitude column name or formula (~lat).
radius: Circle radius in meters (single number, formula ~r, or numeric vector; default 500).
fill_color: Fill color aesthetic (color string, formula ~col, or column name).
palette: Color palette name ("viridis", "plasma", "magma", "turbo", "Spectral", etc.).
fill_opacity: Polygon fill opacity (0 to 1).
stroke: Logical; whether to draw a crisp anti-aliased stroke around each point.
line_color: Border line color string (default "#ffffff").
line_width: Border line width in pixels (default 1.0).
popup: Optional formula (~name), column name, or character vector for click/hover tooltips.
label: Alias for popup.
n_segments: Number of vertices per circle ring (default 24L).
id: Layer ID string.
group: Layer group name shown in the interactive layer switcher.
legend: Logical; whether to automatically add a legend when color is mapped to data.