ndarray-heatmap

Renders ndarray into a canvas.

Install

npm install ndarray-heatmap

Example

Plain old javascript:

<script src="dist/ndarray-heatmap.min.js"></script>
<script>
window.addEventListener('load', function() {
    var shape = [100, 100];
    var data = new Array(shape[0]);
    for(var i = 0; i < shape[0]; ++i) {
        data[i] = new Array(shape[1]);
        for(var j = 0; j < shape[1]; ++j) {
            data[i][j] = j * shape[0] + i;
        }
    }

    var renderer = heatmap.heatmap()
        .data(data)
        .colorRange(['white', 'red']);
    var canvas = renderer();
    document.body.appendChild(canvas);
</script>

ES6 with ndarray:

import heatmap from 'ndarray-heatmap';
import pack from 'ndarray-pack';

var array = pack([
    [0, 0, 0, 0, 0, 0],
    [0, 1, 1, 1, 1, 0],
    [0, 1, 2, 2, 1, 0],
    [0, 1, 1, 1, 1, 0],
    [0, 0, 0, 0, 0, 0]
]);
var renderer = heatmap()
    .data(array)
    .colorRange(['#000000', '#FFFFFF']);
var canvas = renderer();

Or, you can provide existing canvas element:

var canvas = document.createElement('canvas');
renderer(canvas);

If you are not familiar with ndarray please read scijs documentation.