Getting started in EJ2 TypeScript Heatmap chart control

7 May 202524 minutes to read

This section explains the steps to create a simple HeatMap and demonstrates the basic usage of the gantt component using the Essential® JS 2 quickstart seed repository. This seed repository is pre-configured with the Essential® JS 2 package.

This application is integrated with the webpack.config.js configuration and uses the latest version of the webpack-cli. It requires node v14.15.0 or higher. For more information about webpack and its features, refer to the webpack documentation.

Dependencies

For using heat map, the following minimum requirements are needed.

|-- @syncfusion/ej2-heatmap
    |-- @syncfusion/ej2-base
    |-- @syncfusion/ej2-data
    |-- @syncfusion/ej2-svg-base

Set up development environment

Open the command prompt from the required directory, and run the following command to clone the Syncfusion® JavaScript (Essential® JS 2) quickstart project from GitHub.

git clone https://github.com/SyncfusionExamples/ej2-quickstart-webpack- ej2-quickstart

After cloning the application in the ej2-quickstart folder, run the following command line to navigate to the ej2-quickstart folder.

cd ej2-quickstart

Add Syncfusion® JavaScript packages

Syncfusion® JavaScript (Essential® JS 2) packages are available on the npmjs.com public registry. You can install all Syncfusion® JavaScript (Essential® JS 2) controls in a single @syncfusion/ej2 package or individual packages for each control.

The quickstart application is preconfigured with the dependent @syncfusion/ej2 package in the ~/package.json file. Use the following command to install the dependent npm packages from the command prompt.

npm install

Adding heat map to the project

Add an HTML div element of heat map to your index.html. [src/index.html]

<!DOCTYPE html>
<html lang="en">

<head>
    <title>EJ2 Heatmap</title>
    <meta charset="utf-8" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <meta name="description" content="Typescript UI Controls" />
    <meta name="author" content="Syncfusion" />
</head>

<body>
    <!--container which is going to render the Heatmap-->
    <div id='element'>
    </div>
</body>

</html>

Now, import the heat map control into your app.ts to instantiate the heat map and append the heat map instance to the #container [src/app/app.ts]

import { HeatMap } from '@syncfusion/ej2-heatmap';

// initialize HeatMap control
let heatmap: HeatMap = new HeatMap();

// render initialized HeatMap
heatmap.appendTo('#element');

Use the npm start command to run the application in the browser.

npm start

The below example shows a basic Heatmap.

import { HeatMap } from '@syncfusion/ej2-heatmap';

let heatmap: HeatMap = new HeatMap ();

heatmap.appendTo('#element');
<!DOCTYPE html>
<html lang="en">

<head>
    <title>EJ2 HeatMap</title>
    <meta charset="utf-8" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <meta name="description" content="Typescript UI Controls" />
    <meta name="author" content="Syncfusion" />
    <link href="index.css" rel="stylesheet" />
    <script src="https://cdnjs.cloudflare.com/ajax/libs/systemjs/0.19.38/system.js"></script>
    <script src="systemjs.config.js"></script>
<script src="https://cdn.syncfusion.com/ej2/syncfusion-helper.js" type ="text/javascript"></script>
</head>

<body>
    <div id='loader'>Loading....</div>
    <div id='container'>
        <div id='element'></div>
    </div>
</body>

</html>

Module Injection

The heat map controls are segregated into individual feature-wise modules. To use its feature, you need to inject its feature module using the HeatMap.Inject() method. In the current application, the basic heat map is modified to visualize sales revenue data for week, and the tooltip and legend features of the heat map are used. Find the relevant feature modules and descriptions as follows.

  • Legend - Provides the legend feature by injecting it.
  • Tooltip - Provides the tooltip feature by injecting it.

Now, import the above-mentioned modules from the heat map package and inject them into the heat map control using the HeatMap.Inject() method.

import {Legend, Tooltip} from '@syncfusion/ej2-heatmap';
HeatMap.Inject(Legend, Tooltip);

Populate heat map with data

This section explains how to populate the following two-dimensional array data to the heat map.

import { HeatMap, Legend, Tooltip } from '@syncfusion/ej2-heatmap';
HeatMap.Inject(Legend, Tooltip);

let heatmapData: any [] = [
    [73, 39, 26, 39, 94, 0],
    [93, 58, 53, 38, 26, 68],
    [99, 28, 22, 4, 66, 90],
    [14, 26, 97, 69, 69, 3],
    [7, 46, 47, 47, 88, 6],
    [41, 55, 73, 23, 3, 79],
    [56, 69, 21, 86, 3, 33],
    [45, 7, 53, 81, 95, 79],
    [60, 77, 74, 68, 88, 51],
    [25, 25, 10, 12, 78, 14],
    [25, 56, 55, 58, 12, 82],
    [74, 33, 88, 23, 86, 59]];

let heatmap: HeatMap = new HeatMap({
     dataSource: heatmapData,
     }, '#element');
<!DOCTYPE html>
<html lang="en">

<head>
    <title>EJ2 HeatMap</title>
    <meta charset="utf-8" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <meta name="description" content="Typescript UI Controls" />
    <meta name="author" content="Syncfusion" />
    <link href="index.css" rel="stylesheet" />
    <script src="https://cdnjs.cloudflare.com/ajax/libs/systemjs/0.19.38/system.js"></script>
    <script src="systemjs.config.js"></script>
<script src="https://cdn.syncfusion.com/ej2/syncfusion-helper.js" type ="text/javascript"></script>
</head>

<body>
    <div id='loader'>Loading....</div>
    <div id='container'>
        <div id='element'></div>
    </div>
</body>

</html>

Enable axis labels

You can add axis labels to the heat map and format those labels using the xAxis and yAxis properties. Axis labels provide additional information about the data points populated in the heat map.

import { HeatMap, Legend, Tooltip } from '@syncfusion/ej2-heatmap';
HeatMap.Inject(Legend, Tooltip);

let heatmapData: any [] = [
     [73, 39, 26, 39, 94, 0],
     [93, 58, 53, 38, 26, 68],
     [99, 28, 22, 4, 66, 90],
     [14, 26, 97, 69, 69, 3],
     [7, 46, 47, 47, 88, 6],
     [41, 55, 73, 23, 3, 79],
     [56, 69, 21, 86, 3, 33],
     [45, 7, 53, 81, 95, 79],
     [60, 77, 74, 68, 88, 51],
     [25, 25, 10, 12, 78, 14],
     [25, 56, 55, 58, 12, 82],
     [74, 33, 88, 23, 86, 59]];

let heatmap: HeatMap = new HeatMap({
    xAxis: {
        labels: ['Nancy', 'Andrew','Janet', 'Margaret', 'Steven',
        'Michael', 'Robert', 'Laura', 'Anne', 'Paul', 'Karin', 'Mario'],
         },
         yAxis:{
             labels: ['Mon', 'Tues', 'Wed', 'Thurs', 'Fri', 'Sat'],
             },
             dataSource: heatmapData
             }, '#element');
<!DOCTYPE html>
<html lang="en">

<head>
    <title>EJ2 HeatMap</title>
    <meta charset="utf-8" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <meta name="description" content="Typescript UI Controls" />
    <meta name="author" content="Syncfusion" />
    <link href="index.css" rel="stylesheet" />
    <script src="https://cdnjs.cloudflare.com/ajax/libs/systemjs/0.19.38/system.js"></script>
    <script src="systemjs.config.js"></script>
<script src="https://cdn.syncfusion.com/ej2/syncfusion-helper.js" type ="text/javascript"></script>
</head>

<body>
    <div id='loader'>Loading....</div>
    <div id='container'>
        <div id='element'></div>
    </div>
</body>

</html>

Add heat map title

Add a title using the titleSettings property to the heat map to provide quick information to the user
about the data populated in the heat map.

import { HeatMap, Legend, Tooltip } from '@syncfusion/ej2-heatmap';
HeatMap.Inject(Legend, Tooltip);

let heatmapData: any [] = [
     [73, 39, 26, 39, 94, 0],
            [93, 58, 53, 38, 26, 68],
            [99, 28, 22, 4, 66, 90],
            [14, 26, 97, 69, 69, 3],
            [7, 46, 47, 47, 88, 6],
            [41, 55, 73, 23, 3, 79],
            [56, 69, 21, 86, 3, 33],
            [45, 7, 53, 81, 95, 79],
            [60, 77, 74, 68, 88, 51],
            [25, 25, 10, 12, 78, 14],
            [25, 56, 55, 58, 12, 82],
            [74, 33, 88, 23, 86, 59]];

let heatmap: HeatMap = new HeatMap({
    titleSettings: {
            text: 'Sales Revenue per Employee (in 1000 US$)',
            textStyle: {
                size: '15px',
                fontWeight: '500',
                fontStyle: 'Normal',
                fontFamily: 'Segoe UI'
            }
        },
        xAxis: {
            labels: ['Nancy', 'Andrew', 'Janet', 'Margaret', 'Steven',
            'Michael', 'Robert', 'Laura', 'Anne', 'Paul', 'Karin',   'Mario'],
        },
        yAxis: {
            labels: ['Mon', 'Tues', 'Wed', 'Thurs', 'Fri', 'Sat'],
        },
     dataSource: heatmapData,
     }, '#element');
<!DOCTYPE html>
<html lang="en">

<head>
    <title>EJ2 HeatMap</title>
    <meta charset="utf-8" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <meta name="description" content="Typescript UI Controls" />
    <meta name="author" content="Syncfusion" />
    <link href="index.css" rel="stylesheet" />
    <script src="https://cdnjs.cloudflare.com/ajax/libs/systemjs/0.19.38/system.js"></script>
    <script src="systemjs.config.js"></script>
<script src="https://cdn.syncfusion.com/ej2/syncfusion-helper.js" type ="text/javascript"></script>
</head>

<body>
    <div id='loader'>Loading....</div>
    <div id='container'>
        <div id='element'></div>
    </div>
</body>

</html>

Enable legend

Use a legend for the heat map in the visible object by setting the legendSettings property to true and injecting the Legend module using the HeatMap.Inject(Legend) method.

import { HeatMap, Legend, Tooltip } from '@syncfusion/ej2-heatmap';
HeatMap.Inject(Legend, Tooltip);

let heatmapData: any [] = [
     [73, 39, 26, 39, 94, 0],
            [93, 58, 53, 38, 26, 68],
            [99, 28, 22, 4, 66, 90],
            [14, 26, 97, 69, 69, 3],
            [7, 46, 47, 47, 88, 6],
            [41, 55, 73, 23, 3, 79],
            [56, 69, 21, 86, 3, 33],
            [45, 7, 53, 81, 95, 79],
            [60, 77, 74, 68, 88, 51],
            [25, 25, 10, 12, 78, 14],
            [25, 56, 55, 58, 12, 82],
            [74, 33, 88, 23, 86, 59]];

let heatmap: HeatMap = new HeatMap({
    titleSettings: {
            text: 'Sales Revenue per Employee (in 1000 US$)',
            textStyle: {
                size: '15px',
                fontWeight: '500',
                fontStyle: 'Normal',
                fontFamily: 'Segoe UI'
            }
        },
        xAxis: {
            labels: ['Nancy', 'Andrew', 'Janet', 'Margaret', 'Steven',
            'Michael', 'Robert', 'Laura', 'Anne', 'Paul', 'Karin',   'Mario'],
        },
        yAxis: {
            labels: ['Mon', 'Tues', 'Wed', 'Thurs', 'Fri', 'Sat'],
        },
        dataSource: heatmapData,
        legendSettings: {
            visible:true,
            position: 'Right',
            showLabel: true,
            height: "150"
        }
}, '#element');
<!DOCTYPE html>
<html lang="en">

<head>
    <title>EJ2 HeatMap</title>
    <meta charset="utf-8" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <meta name="description" content="Typescript UI Controls" />
    <meta name="author" content="Syncfusion" />
    <link href="index.css" rel="stylesheet" />
    <script src="https://cdnjs.cloudflare.com/ajax/libs/systemjs/0.19.38/system.js"></script>
    <script src="systemjs.config.js"></script>
<script src="https://cdn.syncfusion.com/ej2/syncfusion-helper.js" type ="text/javascript"></script>
</head>

<body>
    <div id='loader'>Loading....</div>
    <div id='container'>
        <div id='element'></div>
    </div>
</body>

</html>

Add data label

Add data labels to improve the readability of the heat map. This can be achieved by setting the showLabel property to true in the cellSettings object.

import { HeatMap, Legend, Tooltip } from '@syncfusion/ej2-heatmap';
HeatMap.Inject(Legend, Tooltip);

let heatmapData: any [] = [
     [73, 39, 26, 39, 94, 0],
            [93, 58, 53, 38, 26, 68],
            [99, 28, 22, 4, 66, 90],
            [14, 26, 97, 69, 69, 3],
            [7, 46, 47, 47, 88, 6],
            [41, 55, 73, 23, 3, 79],
            [56, 69, 21, 86, 3, 33],
            [45, 7, 53, 81, 95, 79],
            [60, 77, 74, 68, 88, 51],
            [25, 25, 10, 12, 78, 14],
            [25, 56, 55, 58, 12, 82],
            [74, 33, 88, 23, 86, 59]];

let heatmap: HeatMap = new HeatMap({
     titleSettings: {
        text: 'Sales Revenue per Employee (in 1000 US$)',
        textStyle: {
                size: '15px',
                fontWeight: '500',
                fontStyle: 'Normal',
                fontFamily: 'Segoe UI'
            }
        },
     cellSettings: {
            showLabel: true,
        },
     xAxis: {
            labels: ['Nancy', 'Andrew', 'Janet', 'Margaret', 'Steven',
            'Michael', 'Robert', 'Laura', 'Anne', 'Paul', 'Karin',   'Mario'],
        },
     yAxis: {
            labels: ['Mon', 'Tues', 'Wed', 'Thurs', 'Fri', 'Sat'],
        },
     dataSource: heatmapData,
     legendSettings: {
            position: 'Right',
            showLabel: true,
            height: "150"
     }
}, '#element');
<!DOCTYPE html>
<html lang="en">

<head>
    <title>EJ2 HeatMap</title>
    <meta charset="utf-8" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <meta name="description" content="Typescript UI Controls" />
    <meta name="author" content="Syncfusion" />
    <link href="index.css" rel="stylesheet" />
    <script src="https://cdnjs.cloudflare.com/ajax/libs/systemjs/0.19.38/system.js"></script>
    <script src="systemjs.config.js"></script>
<script src="https://cdn.syncfusion.com/ej2/syncfusion-helper.js" type ="text/javascript"></script>
</head>

<body>
    <div id='loader'>Loading....</div>
    <div id='container'>
        <div id='element'></div>
    </div>
</body>

</html>

Add custom cell palette

The default palette settings of the heat map cells can be customized by using the paletteSettings property.
Using the palette property in paletteSettings object, you can change the color set for the cells.
You can change the color mode of the cells to fixed or gradient mode using the type property.

import { HeatMap, Legend, Tooltip } from '@syncfusion/ej2-heatmap';
HeatMap.Inject(Legend, Tooltip);

let heatmapData: any [] = [
     [73, 39, 26, 39, 94, 0],
            [93, 58, 53, 38, 26, 68],
            [99, 28, 22, 4, 66, 90],
            [14, 26, 97, 69, 69, 3],
            [7, 46, 47, 47, 88, 6],
            [41, 55, 73, 23, 3, 79],
            [56, 69, 21, 86, 3, 33],
            [45, 7, 53, 81, 95, 79],
            [60, 77, 74, 68, 88, 51],
            [25, 25, 10, 12, 78, 14],
            [25, 56, 55, 58, 12, 82],
            [74, 33, 88, 23, 86, 59]];

let heatmap: HeatMap = new HeatMap({
    titleSettings: {
            text: 'Sales Revenue per Employee (in 1000 US$)',
            textStyle: {
                size: '15px',
                fontWeight: '500',
                fontStyle: 'Normal',
                fontFamily: 'Segoe UI'
            }
        },
    cellSettings: {
            showLabel: true,
        },
     xAxis: {
            labels: ['Nancy', 'Andrew', 'Janet', 'Margaret', 'Steven',
            'Michael', 'Robert', 'Laura', 'Anne', 'Paul', 'Karin',   'Mario'],
        },
      yAxis: {
            labels: ['Mon', 'Tues', 'Wed', 'Thurs', 'Fri', 'Sat'],
        },
      dataSource: heatmapData,
      legendSettings: {
            position: 'Right',
            showLabel: true,
            height: "150"
        },
      paletteSettings: {
            palette: [
                { value: 0, color: '#C06C84' },
                { value: 50, color: '#6C5B7B' },
                { value: 100, color: '#355C7D' }
                ],
            type: "Gradient"
        },
}, '#element');
<!DOCTYPE html>
<html lang="en">

<head>
    <title>EJ2 HeatMap</title>
    <meta charset="utf-8" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <meta name="description" content="Typescript UI Controls" />
    <meta name="author" content="Syncfusion" />
    <link href="index.css" rel="stylesheet" />
    <script src="https://cdnjs.cloudflare.com/ajax/libs/systemjs/0.19.38/system.js"></script>
    <script src="systemjs.config.js"></script>
<script src="https://cdn.syncfusion.com/ej2/syncfusion-helper.js" type ="text/javascript"></script>
</head>

<body>
    <div id='loader'>Loading....</div>
    <div id='container'>
        <div id='element'></div>
    </div>
</body>

</html>

Enable tooltip

The tooltip is used when you cannot display information by using the data labels due to space constraints. You can enable the tooltip by setting the showTooltip property to true and injecting the Tooltip module using the HeatMap.Inject(Tooltip) method.

import { HeatMap, Legend, Tooltip } from '@syncfusion/ej2-heatmap';
HeatMap.Inject(Legend, Tooltip);

let heatmapData: any [] = [
     [73, 39, 26, 39, 94, 0],
            [93, 58, 53, 38, 26, 68],
            [99, 28, 22, 4, 66, 90],
            [14, 26, 97, 69, 69, 3],
            [7, 46, 47, 47, 88, 6],
            [41, 55, 73, 23, 3, 79],
            [56, 69, 21, 86, 3, 33],
            [45, 7, 53, 81, 95, 79],
            [60, 77, 74, 68, 88, 51],
            [25, 25, 10, 12, 78, 14],
            [25, 56, 55, 58, 12, 82],
            [74, 33, 88, 23, 86, 59]];

let heatmap: HeatMap = new HeatMap({
    titleSettings: {
            text: 'Sales Revenue per Employee (in 1000 US$)',
            textStyle: {
                size: '15px',
                fontWeight: '500',
                fontStyle: 'Normal',
                fontFamily: 'Segoe UI'
            }
        },
    cellSettings: {
            showLabel: true,
        },
    xAxis: {
            labels: ['Nancy', 'Andrew', 'Janet', 'Margaret', 'Steven',
            'Michael', 'Robert', 'Laura', 'Anne', 'Paul', 'Karin',   'Mario'],
        },
    yAxis: {
            labels: ['Mon', 'Tues', 'Wed', 'Thurs', 'Fri', 'Sat'],
        },
    dataSource: heatmapData,
    legendSettings: {
            position: 'Right',
            showLabel: true,
            height: "150"
        },
    showTooltip:true,
}, '#element');
<!DOCTYPE html>
<html lang="en">

<head>
    <title>EJ2 HeatMap</title>
    <meta charset="utf-8" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <meta name="description" content="Typescript UI Controls" />
    <meta name="author" content="Syncfusion" />
    <link href="index.css" rel="stylesheet" />
    <script src="https://cdnjs.cloudflare.com/ajax/libs/systemjs/0.19.38/system.js"></script>
    <script src="systemjs.config.js"></script>
<script src="https://cdn.syncfusion.com/ej2/syncfusion-helper.js" type ="text/javascript"></script>
</head>

<body>
    <div id='loader'>Loading....</div>
    <div id='container'>
        <div id='element'></div>
    </div>
</body>

</html>