Add a proportional circles legend — viz_leg

The viz_leg_circles function adds a legend for proportional circles. It draws circles scaled by values, with optional reference lines and labels. The function adds a legend layer to the SVG container.

Usage

viz_leg_circles(
  map,
  id = NULL,
  pos = c(0, 0),
  gap = 2,
  data = c(1, 1000),
  k = 50,
  fixmax = NULL,
  nb = 4,
  circle_fill = "none",
  circle_stroke = "#363636",
  circle_spacing = 5,
  line_stroke = "#363636",
  line_strokeDasharray = "1",
  line_strokeWidth = 0.7,
  line_length = 10,
  values_textAnchor = "start",
  values_dx = 5,
  values_dy = 0,
  values_fill = "#363636",
  values_fontSize = 10,
  values_factor = 1,
  values_decimal = ".",
  values_thousands = " ",
  title = "",
  title_fill = "#363636",
  title_fontSize = 16,
  subtitle = "",
  subtitle_fill = "#363636",
  subtitle_fontSize = 12,
  note = "",
  note_fill = "#363636",
  note_fontSize = 10,
  frame = FALSE,
  frame_margin = 15,
  frame_fill = "white",
  frame_stroke = "black",
  frame_fillOpacity = 0.5,
  ...
)

Arguments

map: A geoviz object created with viz_create.
id: character. Optional. Unique layer id.
pos: numeric vector of length 2. Optional. Legend position (default c(0, 0)).
gap: numeric. Optional. Gap between elements (default 2).
data: numeric vector. Required. Input values.
k: numeric. Optional. Radius of largest circle (default 50).
fixmax: numeric. Optional. Value mapped to radius k.
nb: numeric. Optional. Number of circles (default 4).
circle_fill: character. Optional. Circle fill (default "none").
circle_stroke: character. Optional. Circle stroke (default "#363636").
circle_spacing: numeric. Optional. Spacing between circles (default 5).
line_stroke: character. Optional. Line stroke color (default "#363636").
line_strokeDasharray: character. Optional. Line dash style (default "1").
line_strokeWidth: numeric. Optional. Line width (default 0.7).
line_length: numeric. Optional. Line length (default 10).
values_textAnchor: character. Optional. Text anchor (default "start").
values_dx: numeric. Optional. X shift (default 5).
values_dy: numeric. Optional. Y shift (default 0).
values_fill: character. Optional. Label color (default "#363636").
values_fontSize: numeric. Optional. Font size (default 10).
values_factor: numeric. Optional. Scaling factor (default 1).
values_decimal: character. Optional. Decimal separator (default ".").
values_thousands: character. Optional. Thousands separator (default " ").
title: character. Optional. Title (default "").
title_fill: character. Optional. Title color (default "#363636").
title_fontSize: numeric. Optional. Title size (default 16).
subtitle: character. Optional. Subtitle (default "").
subtitle_fill: character. Optional. Subtitle color (default "#363636").
subtitle_fontSize: numeric. Optional. Subtitle size (default 12).
note: character. Optional. Note (default "").
note_fill: character. Optional. Note color (default "#363636").
note_fontSize: numeric. Optional. Note size (default 10).
frame: logical. Optional. Draw frame (default FALSE).
frame_margin: numeric. Optional. Frame margin (default 15).
frame_fill: character. Optional. Frame fill (default "white").
frame_stroke: character. Optional. Frame stroke (default "black").
frame_fillOpacity: numeric. Optional. Frame opacity (default 0.5).
...: Additional SVG attributes.

Examples

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

viz_create(projection = "EqualEarth", background = "white") |>
viz_path(datum = world, fill = "#f1f3f5") |>
viz_leg_circles(pos = c(20, 20)) |>
viz_render()