@oxth/heatmap NPM

heatmap.js

Heatmaps for the Node.js.

This project was fork from heatmap.js to make support only generate heatmap from backend

How to get started

heatmap is also hosted on npm:

npm install @oxth/heatmap

Importing

import Heatmap from '@oxth/heatmap'

Example

const heatmap = new Heatmap({
  width: 640,
  height: 640,
  backgroundImage: 'img_test.jpg',
  radius: 2.2,
  minOpacity: 0.3,
  maxOpacity: 0.5,
});
const points = getCanvasData();
heatmap.setData(points);
await heatmap.save('test.png');

Configurations

Param	Type	Default	Required	Description
renderer	string	canvas2d	No	Choose your render type (currently only support `2D` canvas)
width	number	640	No	Width of your image.
height	canvas2d	640	No	Height of image.
min	number	null	No	Max data Value for relative gradient computation. if not set, will be derived from data.
max	number	null	No	Min data Value for relative gradient computation. if not set, will be derived from data.
radius	number	20	No	Radius of the data point, in pixels.
opacity	number	0	No	Opacity factor. (This overrides maxOpacity and minOpacity if greater than 0)
minOpacity	number	0	No	Min opacity factor. (will be overridden if opacity set)
maxOpacity	number	1	No	Max opacity factor. (will be overridden if opacity set)
intensity	number	0.25	No	The intensity that will be applied to all datapoints. The lower the intensity factor is, the smoother the gradients will be
useGradientOpacity	boolean	false	No	A boolean flag to use opacity of Color Gradient instead of specify opacity
gradients	{color: number, number, number, number?, offset: number}[]	[{ color: 0, 0, 255, offset: 0, }, { color: 0, 0, 255, offset: 0.2, }, { color: 0, 255, 0, offset: 0.45, }, { color: 255, 255, 0, offset: 0.85, }, { color: 255, 0, 0, offset: 1.0, },]	No	Color Gradient, an array of objects with color value and offset.
backgroundImage	string		No	To set the background for the heatmap.
plugins	object	{}	No	The plugin support.