add_categorical_legend: Add a categorical legend to a Mapbox GL map

In mapgl: Interactive Maps with 'Mapbox GL JS' and 'MapLibre GL JS'

Add a categorical legend to a Mapbox GL map

Description

This function adds a categorical legend to a Mapbox GL map. It supports customizable colors, sizes, and shapes for legend items.

Usage

add_categorical_legend(
  map,
  legend_title,
  values,
  colors,
  circular_patches = FALSE,
  position = "top-left",
  unique_id = NULL,
  sizes = NULL,
  add = FALSE,
  width = NULL
)

Arguments

map	A map object created by the mapboxgl function.
legend_title	The title of the legend.
values	A vector of categories or values to be displayed in the legend.
colors	The corresponding colors for the values. Can be a vector of colors or a single color.
circular_patches	Logical, whether to use circular patches in the legend. Default is FALSE.
position	The position of the legend on the map. One of "top-left", "bottom-left", "top-right", "bottom-right". Default is "top-left".
unique_id	A unique ID for the legend container. If NULL, a random ID will be generated.
sizes	An optional numeric vector of sizes for the legend patches, or a single numeric value. If provided as a vector, it should have the same length as values. If circular_patches is FALSE (for square patches), sizes represent the width and height of the patch in pixels. If circular_patches is TRUE, sizes represent the radius of the circle.
add	Logical, whether to add this legend to existing legends (TRUE) or replace existing legends (FALSE). Default is FALSE.
width	The width of the legend. Can be specified in pixels (e.g., "250px") or as "auto". Default is NULL, which uses the built-in default.

Value

The updated map object with the legend added.

Examples

## Not run: 
library(mapboxgl)
map <- mapboxgl(
    center = c(-96, 37.8),
    zoom = 3
)
map %>% add_categorical_legend(
    legend_title = "Population",
    values = c("Low", "Medium", "High"),
    colors = c("#FED976", "#FEB24C", "#FD8D3C"),
    circular_patches = TRUE,
    sizes = c(10, 15, 20),
    width = "300px"
)

## End(Not run)

mapgl documentation built on Nov. 1, 2024, 5:08 p.m.