d3-scale-chromatic

What is d3-scale-chromatic?

The d3-scale-chromatic package provides color schemes designed to work with d3-scale's sequential, diverging, and categorical color scales. It includes a variety of color palettes that can be used for data visualization, such as for mapping data values to colors in charts and graphs.

What are d3-scale-chromatic's main functionalities?

Sequential Color Schemes

Sequential color schemes are ideal for displaying ordered data that progresses from low to high. The package provides a variety of single-hue and multi-hue color schemes.

import { scaleSequential } from 'd3-scale';
import { interpolateBlues } from 'd3-scale-chromatic';

const colorScale = scaleSequential(interpolateBlues).domain([0, 100]);
console.log(colorScale(50)); // Outputs a color from the 'Blues' sequential color scheme

Diverging Color Schemes

Diverging color schemes are used to visualize data that diverges from a median value, with contrasting colors on either side. This is useful for highlighting deviation from a midpoint.

import { scaleDiverging } from 'd3-scale';
import { interpolatePiYG } from 'd3-scale-chromatic';

const colorScale = scaleDiverging(interpolatePiYG).domain([0, 50, 100]);
console.log(colorScale(50)); // Outputs the middle color from the 'PiYG' diverging color scheme

Categorical Color Schemes

Categorical color schemes are used for discrete data that falls into distinct categories. The package provides several categorical color palettes with a fixed number of colors.

import { scaleOrdinal } from 'd3-scale';
import { schemeCategory10 } from 'd3-scale-chromatic';

const colorScale = scaleOrdinal(schemeCategory10);
console.log(colorScale('category1')); // Outputs a color from the 'Category10' categorical color scheme

Other packages similar to d3-scale-chromatic

chroma-js

Chroma.js is a powerful library for all kinds of color conversions and color scales. It offers similar functionalities to d3-scale-chromatic but with additional features like color manipulation, blending, and more complex color scale generation.

colorbrewer

ColorBrewer is an original source of some of the color schemes found in d3-scale-chromatic. It provides a set of color palettes for cartography, which can be used independently of D3. However, it does not offer the same level of integration with D3's scale functions.

palette.js

Palette.js is a smaller library that can generate color palettes for data visualization. It is not as comprehensive as d3-scale-chromatic and lacks the direct integration with D3's scale functions.

README

d3-scale-chromatic

This module provides sequential, diverging and categorical color schemes designed to work with d3-scale’s scaleOrdinal and scaleSequential. Most of these schemes are derived from Cynthia A. Brewer’s ColorBrewer. Since ColorBrewer publishes only discrete color schemes, the sequential and diverging scales are interpolated using uniform B-splines.

Resources

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• Examples
• Releases
• Getting help