classification_helpers: Extract information from classification and continuous scale...

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

Extract information from classification and continuous scale objects

Description

These functions extract different components from mapgl_classification objects (created by step_equal_interval(), step_quantile(), step_jenks()) and mapgl_continuous_scale objects (created by interpolate_palette()).

Usage

get_legend_labels(
  scale,
  format = "none",
  currency_symbol = "$",
  digits = 2,
  big_mark = ",",
  suffix = "",
  prefix = ""
)

get_legend_colors(scale)

get_breaks(scale)

## S3 method for class 'mapgl_classification'
print(x, format = "none", ...)

## S3 method for class 'mapgl_continuous_scale'
print(x, format = "none", ...)

Arguments

scale	A mapgl_classification or mapgl_continuous_scale object.
format	A character string specifying the format type for labels. Options include: "none" (default): No special formatting "currency": Format as currency (e.g., "$1,234") "percent": Format as percentage (e.g., "12.3%") "scientific": Format in scientific notation (e.g., "1.2e+03") "compact": Format with abbreviated units (e.g., "1.2K", "3.4M")
currency_symbol	The currency symbol to use when format = "currency". Defaults to "$".
digits	The number of decimal places to display. Defaults to 2.
big_mark	The character to use as thousands separator. Defaults to ",".
suffix	An optional suffix to add to all values (e.g., "km", "mph").
prefix	An optional prefix to add to all values (useful for compact currency like "$1.2K").
x	A mapgl_classification or mapgl_continuous_scale object to print.
...	Additional arguments passed to formatting functions.

Value

get_legend_labels()

A character vector of formatted legend labels

get_legend_colors()

A character vector of colors

get_breaks()

A numeric vector of break values

Examples

## Not run: 
# Texas county income data
library(tidycensus)
tx <- get_acs(geography = "county", variables = "B19013_001",
              state = "TX", geometry = TRUE)

# Classification examples
eq_class <- step_equal_interval("estimate", tx$estimate, n = 4)
labels <- get_legend_labels(eq_class, format = "currency")
colors <- get_legend_colors(eq_class)
breaks <- get_breaks(eq_class)

# Continuous scale examples
scale <- interpolate_palette("estimate", tx$estimate, method = "quantile", n = 5)
labels <- get_legend_labels(scale, format = "compact", prefix = "$")
colors <- get_legend_colors(scale)

## End(Not run)

mapgl documentation built on June 16, 2025, 5:09 p.m.