Leaflet.heat

A tiny and fast Leaflet heatmap plugin. This is a fork of the original Leaflet.heat with modern improvements:

• Written in TypeScript
• ESM (ECMAScript Modules) support
• Modern build tooling with Vite
• Type definitions included
• Better tree-shaking support

Installation

npm install @linkurious/leaflet-heat

Usage

import L from "leaflet";
import { heatLayer } from "@linkurious/leaflet-heat";

const map = L.map("map").setView([0, 0], 2);

L.tileLayer("https://tile.openstreetmap.org/{z}/{x}/{y}.png", {
  attribution:
    '&copy; <a href="https://osm.org/copyright">OpenStreetMap</a> contributors',
}).addTo(map);

const points = [
  [50.5, 30.5, "0.8"], // lat, lng, intensity
  [50.6, 30.4, "0.5"],
  [50.3, 30.6, "0.2"],
];

const heat = heatLayer(points).addTo(map);

API

heatLayer(points, options?)

Creates a heatmap layer given an array of points and an optional options object.

Points

An array of [lat, lng, intensity] or [lat, lng] arrays. The intensity should be a number between 0 and 1.

Options

Development

# Install dependencies
npm install

# Run tests
npm test

# Build the library
npm run build

# Run the demo in development mode
npm run demo:dev

# Build the demo
npm run demo:build

# Preview the built demo
npm run demo:preview

License

This project is dual-licensed:

1. The original Leaflet.heat code (up to version 0.2.0) is licensed under the MIT License.
2. All changes and improvements made by Linkurious are licensed under the Apache 2.0 License.

These licenses are compatible with each other, and you can use this software under either license. The Apache 2.0 License provides additional patent protection compared to the MIT License.

Demos

• 10,000 points →
• Adding points dynamically →

Basic Usage

var heat = L.heatLayer([
    [50.5, 30.5, 0.2], // lat, lng, intensity
    [50.6, 30.4, 0.5],
    ...
], {radius: 25}).addTo(map);

To include the plugin, just use leaflet-heat.js from the dist folder:

<script src="leaflet-heat.js"></script>

Building

To build the dist files run: npm install && npm run prepublish

Reference

L.heatLayer(latlngs, options)

Constructs a heatmap layer given an array of points and an object with the following options:

• minOpacity - the minimum opacity the heat will start at
• maxZoom - zoom level where the points reach maximum intensity (as intensity scales with zoom), equals maxZoom of the map by default
• max - maximum point intensity, 1.0 by default
• radius - radius of each "point" of the heatmap, 25 by default
• blur - amount of blur, 15 by default
• gradient - color gradient config, e.g. {0.4: 'blue', 0.65: 'lime', 1: 'red'}
• pane - Map pane where the heat will be drawn. Defaults to 'overlayPane'.

Each point in the input array can be either an array like [50.5, 30.5, 0.5], or a Leaflet LatLng object.

Optional third argument in each LatLng point (altitude) represents point intensity. Unless max option is specified, intensity should range between 0.0 and 1.0.

Methods

• setOptions(options): Sets new heatmap options and redraws it.
• addLatLng(latlng): Adds a new point to the heatmap and redraws it.
• setLatLngs(latlngs): Resets heatmap data and redraws it.
• redraw(): Redraws the heatmap.

Changelog

0.2.0 — Oct 26, 2015

• Fixed intensity to work properly with max option.
• Fixed zoom animation on Leaflet 1.0 beta 2.
• Fixed tiles and point intensity in demos.

0.1.3 — Nov 25, 2015

• Fixed some edge cases when handling point intensity.
• Added minOpacity option.

0.1.2 — Nov 5, 2014

• Added compatibility with Leaflet 0.8-dev.

0.1.1 — Apr 22, 2014

• Fixed overlaying two heatmaps on top of each other.
• Fixed rare animation issues.

0.1.0 — Feb 3, 2014

• Added addLatLng, setLatlngs, setOptions and redraw methods.
• Added max option and support for different point intensity values (through LatLng third argument).
• Added gradient option to customize colors.

0.0.1 — Jan 31, 2014

• Initial release.