Circle layer

The viz_circle function draws circles on the map from a spatial data frame or from a single position. It can be used to create proportional symbol maps with optional collision avoidance.

Usage

viz_circle(
  map,
  data = NULL,
  id = NULL,
  pos = c(0, 0),
  r = 10,
  k = 50,
  fixmax = NULL,
  dodge = FALSE,
  iteration = 200,
  sort = NULL,
  descending = NULL,
  coords = "geo",
  fill = NULL,
  stroke = "white",
  tip = FALSE,
  ...
)

Arguments

map

A geoviz map created with viz_create.

data

object. Optional. A spatial data frame.

id

character. Optional. Unique layer id.

pos

numeric vector. Optional. Position of a single circle (default c(0, 0)).

r

numeric or character. Optional. Circle radius (default 10). Can be a fixed value or the name of a field containing numerical values.

k

numeric. Optional. Radius of the largest circle (default 50).

fixmax

numeric. Optional. Value corresponding to the circle of radius k. Useful to ensure comparability between maps.

dodge

logical. Optional. Avoid circle overlap (default FALSE).

iteration

numeric. Optional. Number of iterations for dodging (default 200).

sort

character or function. Optional. Field name or function to sort circles.

descending

logical. Optional. Sorting order.

coords

character. Optional. Coordinate system (default "geo"). Use "svg" if coordinates are already expressed in the SVG coordinate space.

fill

character or function. Optional. Fill color.

stroke

character or function. Optional. Stroke color (default "white").

tip

logical or function. Optional. Tooltip definition (default FALSE). Use TRUE to display all fields.

...

Additional SVG attributes (e.g. strokeDasharray, strokeWidth, opacity, strokeLinecap, etc.).

Examples

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

viz_create(projection = "EqualEarth") |>
viz_path(datum = world, fill = "#f1f3f5") |>
viz_circle(data = world, r = 30, fill = "#38896F") |>
viz_render()