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How to use map heat map to display city heat in ECharts
ECharts is a powerful visual chart library that provides various chart types for developers Use, including heat maps. Map heat maps can be used to show the popularity of cities or regions, helping us quickly understand the popularity or density of different places. This article will introduce how to use the map heat map in ECharts to display city heat, and provide code examples for reference.
First of all, we need a map file containing geographical information. ECharts officially provides various map files. We can choose the appropriate map file according to our needs. Taking the map of China as an example, the JSON file of the China map can be found on the ECharts official website (https://echarts.apache.org/zh/download-map.html). Download the file and place it in the appropriate location in your project.
Next, we need to prepare the display data. Suppose we want to display the popularity of various cities in China, we can use a data collection containing city names and popularity values. For example, we can use a JSON array to store this data. Each array element contains the city name and the corresponding heat value, as shown below:
var data = [ {name: '北京', value: 100}, {name: '上海', value: 90}, {name: '广州', value: 80}, // 其他城市数据... ];
Then, we need to create an ECharts instance containing the map heat map , and associate the data with the map file. The following is a sample code for creating a map heat map:
// 创建ECharts实例 var myChart = echarts.init(document.getElementById('mapContainer')); // 配置地图热力图 var option = { // 使用中国地图 map: 'china', // 设置地图的放大与缩小的按钮不可见 roam: false, // 配置地图热力图的数据 series: [{ type: 'heatmap', coordinateSystem: 'geo', data: data }] }; // 关联数据与地图文件 myChart.setOption(option);
In the above sample code, we first create an ECharts instance and specify the container in which it is located. Then, we configured the relevant parameters of the map heat map. Among them, map
specifies the map file used, roam
sets the visibility of the map zoom button, series
specifies the data of the heat map and the coordinates used Tie. Finally, we associate the data with the map file through the setOption
method.
The HTML code that displays this map heat map is as follows:
<!DOCTYPE html> <html> <head> <meta charset="utf-8"> <title>地图热力图示例</title> <script src="echarts.min.js"></script> </head> <body> <div id="mapContainer" style="width: 800px; height: 600px;"></div> <script> // 上述代码 </script> </body> </html>
In the above HTML code, we introduced the JavaScript file of ECharts and created a container containing the map heat map. By setting the width and height of the container, we can resize the map heat map.
Through the above steps, we can use map heat maps to display city heat in ECharts. According to actual needs, we can adjust the color depth of the map heat map according to the city's heat value to show the difference in city heat. In addition, ECharts also provides a wealth of configuration options, which can achieve more personalized map heat map effects by adjusting configuration parameters.
To sum up, using the map heat map in ECharts to display the heat of a city is a simple and effective method. By properly preparing map files and data, and combining ECharts' configuration options, we can easily create a variety of map heat maps and display the city's heat at a glance. I hope the sample code provided in this article will be helpful to you and speed up your development process of map heat maps in ECharts.
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