Highcharts Heat Map
In this section, we will introduce the Heat Map in Highcharts.
We have already learned about the Highcharts configuration syntax in previous sections. Now, let's take a look at other configurations in Highcharts.
Heat Map
Chart Configuration
Set the chart type to 'heatmap'. The chart.type describes the type of the chart. The default value is "line".
var chart = {
type: 'heatmap'
};
Example
Filename: highcharts_heat_map.htm
<html>
<head>
<title>Highcharts Tutorial | tutorialpro.org(tutorialpro.org)</title>
<script src="http://apps.bdimg.com/libs/jquery/2.1.4/jquery.min.js"></script>
<script src="/try/demo_source/highcharts.js"></script>
<script src="/try/demo_source/highcharts-more.js"></script>
<script src="http://code.highcharts.com/modules/heatmap.js"></script>
</head>
<body>
<div id="container" style="width: 550px; height: 400px; margin: 0 auto"></div>
<script language="JavaScript">
$(document).ready(function() {
var chart = {
type: 'heatmap',
marginTop: 40,
marginBottom: 80
};
var title = {
text: 'Sales per employee per week'
};
var xAxis = {
categories: ['Alexander', 'Marie', 'Maximilian', 'Sophia', 'Lukas', 'Maria', 'Leon', 'Anna', 'Tim', 'Laura']
};
var yAxis = {
categories: ['Monday', 'Tuesday', 'Wednesday', 'Thursday', 'Friday'],
title: null
};
var colorAxis = {
min: 0,
minColor: '#FFFFFF',
maxColor: Highcharts.getOptions().colors[0]
};
var legend = {
align: 'right',
layout: 'vertical',
margin: 0,
verticalAlign: 'top',
y: 25,
symbolHeight: 280
};
var tooltip = {
formatter: function () {
return '<b>' + this.series.xAxis.categories[this.point.x] + '</b> sold <br><b>' +
this.point.value + '</b> items on <br><b>' + this.series.yAxis.categories[this.point.y] + '</b>';
}
};
var series= [{
name: 'Sales per employee',
borderWidth: 1,
data: [[0, 0, 10], [0, 1, 19], [0, 2, 8], [0, 3, 24], [0, 4, 67], [1, 0, 92], [1, 1, 58], [1, 2, 78], [1, 3, 117], [1, 4, 48], [2, 0, 35], [2, 1, 15], [2, 2, 123], [2, 3, 64], [2, 4, 52], [3, 0, 72], [3, 1, 132], [3, 2, 114], [3, 3, 19], [3, 4, 16], [4, 0, 38], [4, 1, 5], [4, 2, 8], [4, 3, 117], [4, 4, 115], [5, 0, 88], [5, 1, 32], [5, 2, 12], [5, 3, 6], [5, 4, 120], [6, 0, 13], [6, 1, 44], [6, 2, 88], [6, 3, 98], [6, 4, 96], [7, 0, 31], [7, 1, 1], [7, 2, 82], [7, 3, 32], [7, 4, 30], [8, 0, 85], [8, 1, 97], [8, 2, 123], [8, 3, 64], [8, 4, 84], [9, 0, 47], [9, 1, 114], [9, 2, 31], [9, 3, 48], [9, 4, 91]],
dataLabels: {
enabled: true,
color: '#000000'
}
}];
var json = {};
json.chart = chart;
json.title = title;
json.xAxis = xAxis;
json.yAxis = yAxis;
json.colorAxis = colorAxis;
json.legend = legend;
json.tooltip = tooltip;
json.series = series;
$('#container').highcharts(json);
});
</script>
</body>
</html>
The output of the above example is:
Large Data Heat Map
Example
Filename: highcharts_heat_largemap.htm (Click the example to view the full source code)
<html>
<head>
<title>Highcharts Tutorial | tutorialpro.org(tutorialpro.org)</title>
<script src="http://apps.bdimg.com/libs/jquery/2.1.4/jquery.min.js"></script>
<script src="/try/demo_source/highcharts.js"></script>
<script src="http://code.highcharts.com/modules/data.js"></script>
<script src="http://code.highcharts.com/modules/heatmap.js"></script>
</head>
<body>
<div id="container" style="width: 550px; height: 400px; margin: 0 auto"></div>
<!-- Omitted data starts, click "Try it" for details -->
……
……
……
<!-- Omitted data ends, click "Try it" for details -->
<script language="JavaScript">
$(document).ready(function() {
/**
* This plugin extends Highcharts in two ways:
* - Use HTML5 canvas instead of SVG for rendering of the heatmap squares. Canvas
* outperforms SVG when it comes to thousands of single shapes.
* - Add a K-D-tree to find the nearest point on mouse move. Since we no longer have SVG shapes
* to capture mouseovers, we need another way of detecting hover points for the tooltip.
*/
(function (H) {
var wrap = H.wrap,
seriesTypes = H.seriesTypes;
/**
* Get the canvas context for a series
*/
H.Series.prototype.getContext = function () {
var canvas;
if (!this.ctx) {
canvas = document.createElement('canvas');
canvas.setAttribute('width', this.chart.plotWidth);
canvas.setAttribute('height', this.chart.plotHeight);
canvas.style.position = 'absolute';
canvas.style.left = this.group.translateX + 'px';
canvas.style.top = this.group.translateY + 'px';
canvas.style.zIndex = 0;
canvas.style.cursor = 'crosshair';
this.chart.container.appendChild(canvas);
if (canvas.getContext) {
this.ctx = canvas.getContext('2d');
}
}
return this.ctx;
}
/**
* Wrap the drawPoints method to draw the points in canvas instead of the slower SVG,
* that requires one shape each point.
*/
H.wrap(H.seriesTypes.heatmap.prototype, 'drawPoints', function (proceed) {
var ctx;
if (this.chart.renderer.forExport) {
// Run SVG shapes
proceed.call(this);
} else {
if (ctx = this.getContext()) {
// draw the columns
H.each(this.points, function (point) {
var plotY = point.plotY,
shapeArgs;
if (plotY !== undefined && !isNaN(plotY) && point.y !== null) {
shapeArgs = point.shapeArgs;
ctx.fillStyle = point.pointAttr[''].fill;
ctx.fillRect(shapeArgs.x, shapeArgs.y, shapeArgs.width, shapeArgs.height);
}
});
} else {
this.chart.showLoading("Your browser doesn't support HTML5 canvas, <br>please use a modern browser");
// Uncomment this to provide low-level (slow) support in oldIE. It will cause script errors on
// charts with more than a few thousand points.
//proceed.call(this);
}
}
}); }(Highcharts));
var data = { csv: document.getElementById('csv').innerHTML, parsed: function () { start = +new Date(); } }; var chart = { type: 'heatmap', margin: [60, 10, 80, 50] }; var title = { text: 'Highcharts extended heat map', align: 'left', x: 40 }; var subtitle = { text: 'Temperature variation by day and hour through 2013', align: 'left', x: 40 };
var xAxis = { type: 'datetime', min: Date.UTC(2013, 0, 1), max: Date.UTC(2014, 0, 1), labels: { align: 'left', x: 5, y: 14, format: '{value:%B}' // long month }, showLastLabel: false, tickLength: 16 };
var yAxis = { title: { text: null }, labels: { format: '{value}:00' }, minPadding: 0, maxPadding: 0, startOnTick: false, endOnTick: false, tickPositions: [0, 6, 12, 18, 24], tickWidth: 1, min: 0, max: 23, reversed: true };
var colorAxis = { stops: [ [0, '#3060cf'], [0.5, '#fffbbc'], [0.9, '#c4463a'], [1, '#c4463a'] ], min: -15, max: 25, startOnTick: false, endOnTick: false, labels: { format: '{value}?' } };
var series = [{ borderWidth: 0, nullColor: '#EFEFEF', colsize: 24 * 36e5, // one day tooltip: { headerFormat: 'Temperature<br/>', pointFormat: '{point.x:%e %b, %Y} {point.y}:00: <b>{point.value} ?</b>' }, turboThreshold: Number.MAX_VALUE // #3404, remove after 4.0.5 release }];
var json = {}; json.chart = chart; json.data = data; json.title = title; json.xAxis = xAxis; json.yAxis = yAxis; json.colorAxis = colorAxis; json.series = series;
$('#container').highcharts(json); }); </script> </body> </html>
The above example displays the following result: