Generating Baidu Map Heatmaps with PHP

1. Introduction

Heatmaps visualize data density using color gradients, and in PHP you can create and display them by leveraging the Baidu Map API. This guide walks through the complete workflow.

2. Preparation

First, obtain a Baidu Map developer account, create an application, and acquire an API access key.

3. Import Baidu Map API

Download the Baidu Map API library, place it in your project (e.g., under vendor ), and include it in your PHP code:

require 'vendor/bdmapapi-master/autoload.php';
use BaiduMapAPIHeatMapHeatMap;

4. Prepare Heatmap Data

Collect latitude, longitude, and weight values into an array. Example data structure:

$heatPoints = [
    ['lng' => 113.943062, 'lat' => 22.549006, 'count' => 10],
    ['lng' => 114.064871, 'lat' => 22.548925, 'count' => 20],
    ['lng' => 113.88908,  'lat' => 22.580623, 'count' => 30],
    // more points …
];

5. Generate Heatmap Data

Create a HeatMap instance and configure basic parameters:

$heatmap = new HeatMap(); // create instance
$heatmap->setScale(3);      // weight scaling factor
$heatmap->setOpacity(0.8);  // transparency

Add each point to the heatmap:

foreach ($heatPoints as $point) {
    $heatmap->addPoint($point['lng'], $point['lat'], $point['count']);
}

Finally, obtain the heatmap image data:

$heatmapData = $heatmap->getHeatMapImage();

6. Display the Heatmap

Insert a map container in your HTML:

<div id="map"></div>

Use JavaScript to create a Baidu Map instance, add a heatmap overlay, and feed the generated data:

var map = new BMap.Map("map"); // create map instance
var heatmapOverlay = new BMapLib.HeatmapOverlay(); // overlay instance
map.centerAndZoom(new BMap.Point(113.943062, 22.549006), 13); // set center and zoom
map.addOverlay(heatmapOverlay); // add overlay
heatmapOverlay.setDataSet({ data:
}); // set data

7. Conclusion

By following these steps you can easily generate and render heatmaps in a PHP project using the Baidu Map API, turning raw coordinate data into an intuitive visual representation.