How to use JS and Baidu Maps to implement map heat map function
How to use JS and Baidu Maps to implement the map heat map function
Introduction:
With the rapid development of the Internet and mobile devices, maps have become a common application scenarios. As a visual display method, heat maps can help us understand the distribution of data more intuitively. This article will introduce how to use JS and Baidu Map API to implement the map heat map function, and provide specific code examples.
- Preparation work:
Before you start, you need to prepare the following items: - A Baidu developer account, create an application, and obtain the corresponding API Key.
- A basic HTML page used to display maps and heat maps.
- Introduce Baidu Map API and Heat Gallery:
Introduce the relevant script files of Baidu Map API and Heat Gallery in the tag of the HTML page. The code is as follows:
<script src="http://api.map.baidu.com/api?v=2.0&ak=你的API Key"></script> <script src="http://api.map.baidu.com/library/Heatmap/2.0/src/Heatmap_min.js"></script>
Please replace "your API Key" with your own API Key.
- Create a map:
Use theBMap.Map()
method of Baidu Map API to create a map object and set its center point and zoom level. The code is as follows:
var map = new BMap.Map("mapContainer"); var point = new BMap.Point(116.404, 39.915); map.centerAndZoom(point, 15);
Please replace "mapContainer" with the ID of the
- Add a heat map overlay:
Use theBMapLib.HeatmapOverlay()
method provided by the heat library to create a heat map overlay object. The code is as follows:
var heatmapOverlay = new BMapLib.HeatmapOverlay({ radius: 20 }); map.addOverlay(heatmapOverlay);
You can adjust the radius of the heat map by setting the radius
attribute.
- Set heat map data:
Call thesetDataSet()
method of the heat map object and pass in an array containing data points to set the heat map data. The format of data points is{lng: longitude, lat: latitude, count: thermal value}
. The code is as follows:
var data = [ {lng: 116.404, lat: 39.915, count: 10}, {lng: 116.414, lat: 39.915, count: 20}, {lng: 116.404, lat: 39.925, count: 30}, // 其他数据点... ]; heatmapOverlay.setDataSet({data: data, max: 100});
Please provide the correct data point array according to actual needs.
- Rendering heat map:
Call theshow()
method of the heat map object to render the heat map. The code is as follows:
heatmapOverlay.show();
- Conclusion:
At this point, you have successfully implemented the map heat map function using JS and Baidu Map API. I hope this article can help you. If you have any questions or doubts, please leave a message for discussion.
The above are the detailed steps and sample code on how to use JS and Baidu Maps to implement the map heat map function. Hope it helps readers. If readers want to know more about map heat maps, they can refer to the official documentation of Baidu Map API. I wish readers success in achieving their goals during the development process!
The above is the detailed content of How to use JS and Baidu Maps to implement map heat map function. For more information, please follow other related articles on the PHP Chinese website!

JavaScript is widely used in websites, mobile applications, desktop applications and server-side programming. 1) In website development, JavaScript operates DOM together with HTML and CSS to achieve dynamic effects and supports frameworks such as jQuery and React. 2) Through ReactNative and Ionic, JavaScript is used to develop cross-platform mobile applications. 3) The Electron framework enables JavaScript to build desktop applications. 4) Node.js allows JavaScript to run on the server side and supports high concurrent requests.

Python is more suitable for data science and automation, while JavaScript is more suitable for front-end and full-stack development. 1. Python performs well in data science and machine learning, using libraries such as NumPy and Pandas for data processing and modeling. 2. Python is concise and efficient in automation and scripting. 3. JavaScript is indispensable in front-end development and is used to build dynamic web pages and single-page applications. 4. JavaScript plays a role in back-end development through Node.js and supports full-stack development.

C and C play a vital role in the JavaScript engine, mainly used to implement interpreters and JIT compilers. 1) C is used to parse JavaScript source code and generate an abstract syntax tree. 2) C is responsible for generating and executing bytecode. 3) C implements the JIT compiler, optimizes and compiles hot-spot code at runtime, and significantly improves the execution efficiency of JavaScript.

JavaScript's application in the real world includes front-end and back-end development. 1) Display front-end applications by building a TODO list application, involving DOM operations and event processing. 2) Build RESTfulAPI through Node.js and Express to demonstrate back-end applications.

The main uses of JavaScript in web development include client interaction, form verification and asynchronous communication. 1) Dynamic content update and user interaction through DOM operations; 2) Client verification is carried out before the user submits data to improve the user experience; 3) Refreshless communication with the server is achieved through AJAX technology.

Understanding how JavaScript engine works internally is important to developers because it helps write more efficient code and understand performance bottlenecks and optimization strategies. 1) The engine's workflow includes three stages: parsing, compiling and execution; 2) During the execution process, the engine will perform dynamic optimization, such as inline cache and hidden classes; 3) Best practices include avoiding global variables, optimizing loops, using const and lets, and avoiding excessive use of closures.

Python is more suitable for beginners, with a smooth learning curve and concise syntax; JavaScript is suitable for front-end development, with a steep learning curve and flexible syntax. 1. Python syntax is intuitive and suitable for data science and back-end development. 2. JavaScript is flexible and widely used in front-end and server-side programming.

Python and JavaScript have their own advantages and disadvantages in terms of community, libraries and resources. 1) The Python community is friendly and suitable for beginners, but the front-end development resources are not as rich as JavaScript. 2) Python is powerful in data science and machine learning libraries, while JavaScript is better in front-end development libraries and frameworks. 3) Both have rich learning resources, but Python is suitable for starting with official documents, while JavaScript is better with MDNWebDocs. The choice should be based on project needs and personal interests.


Hot AI Tools

Undresser.AI Undress
AI-powered app for creating realistic nude photos

AI Clothes Remover
Online AI tool for removing clothes from photos.

Undress AI Tool
Undress images for free

Clothoff.io
AI clothes remover

Video Face Swap
Swap faces in any video effortlessly with our completely free AI face swap tool!

Hot Article

Hot Tools

MantisBT
Mantis is an easy-to-deploy web-based defect tracking tool designed to aid in product defect tracking. It requires PHP, MySQL and a web server. Check out our demo and hosting services.

Dreamweaver Mac version
Visual web development tools

SublimeText3 Mac version
God-level code editing software (SublimeText3)

PhpStorm Mac version
The latest (2018.2.1) professional PHP integrated development tool

WebStorm Mac version
Useful JavaScript development tools