Does JavaScript support trigonometric functions?
JavaScript supports trigonometric functions. Trigonometric functions in js are all static methods and must be called using Math, so the syntax format is "Math.sin(x)", "Math.cos(x)", "Math.tan(x)".
The operating environment of this tutorial: windows7 system, javascript version 1.8.5, Dell G3 computer.
JavaScript supports trigonometric functions. They are: "Math.sin(x)", "Math.cos(x)", "Math.tan(x)".
Let’s take a look at JavaScript’s support for trigonometric functions.
First of all, let’s review the basic knowledge of trigonometric functions that we learned in high school. I will introduce a few simple ones here. The first one is the sin function, the second one is the cos function, and the third one is It is the tan function, four or four is the atan function, and the sin function in mathematics is actually the value obtained by comparing the opposite side of a triangle to the hypotenuse. Let’s look at an image
Then cos30=x/r, the cos function is the ratio of the opposite side to the superior side, tan30=y/x, and the tan function is the ratio of the opposite side to the superior side, Through these formulas, we can easily get the value of this trigonometric function, and then we can do interesting things with these values! !
There are actually some differences between the trigonometric functions in JavaScript and the trigonometric functions in mathematics. The first is that the writing is different. The trigonometric functions in js are all static methods and must be called using Math. The three functions are Math.sin(), Math.cos(), Math.tan().
This is easy to understand. Then the second difference is that the parameters accepted by trigonometric functions in mathematics are angles, but the parameters accepted in js are radians. Some friends may be confused. Radian angles What the hell? ? ? Don't worry, here is a brief introduction. Let's first look at a circle
#If the length of a side of a circle is equal to the radius of the circle, then this side represents One radian, just like the red part in the picture, represents one radian. This is actually just a concept. What we really want to use is to convert the angle we want into radians. Here we directly apply the mathematical formula 1 Angle = π /180 Then 10 angles are equal to 10*π/180
Then we have to use js’s Math.sin() to calculate the 30-degree angle What is equal to, then it should be written as Math.sin(30*Math.PI/180). Note here that π in js is Math.PI. I believe that everyone must have some understanding of the trigonometric functions of js here, so let's take a look at a small practical example.
First of all, there is a need. There is a small ball on the page. I want my mouse to move there when my mouse is placed on the page. The ball will move to the corresponding position. Note that it does not move to the position of the mouse, but to the corresponding position. It is not easy to post the URL here. Let's post a picture to see.
Among them, the red ball represents a muzzle. The blue ball represents the position of the mouse. When the mouse is placed at different positions on the page, the red ball will move to the corresponding angle, but we also see that there is an r, indicating the range of the plane. Well, the range that the red ball can move is actually the radius of a circle. The larger r is, the greater the range the ball can move! ! (For those who don’t understand, just copy the following example and run it.)
The implementation of this function requires us to use trigonometric functions to detect the position of the mouse and detect it in a 360-degree range. , here you need to calculate the distance to the left and the distance to the top of the red ball through the angle, and then assign them to the ball! ! Let’s look at another picture
#The following is the code of this case, friends who are interested can take a look!
/***********例子来了*************/
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html;charset=UTF-8">
<title>Document</title>
<style>
#box{width:30px;height:30px;background:red;position:absolute;top:400px;left:400px;border-radius:15px;}
</style>
</head>
<body>
<p id="box"></p>
</body>
<script>
var obox = document.getElementById('box');
var r=50;
document.onmousemove=function(ev){
var oev = ev||event;
var x = Math.abs(oev.clientX-obox.offsetLeft);
var y = Math.abs(oev.clientY-obox.offsetTop);
var angle = Math.atan(y/x);
var cx=0;
var cy=0;
if(oev.clientX>=obox.offsetLeft && oev.clientY<=obox.offsetTop){
cx = Math.cos(angle)*r;
cy = Math.sin(angle)*-r;
}
if(oev.clientX<obox.offsetLeft && oev.clientY<obox.offsetTop){
cx = Math.cos(angle)*-r;
cy = Math.sin(angle)*-r;
}
if(oev.clientX<obox.offsetLeft && oev.clientY>obox.offsetTop){
cx = Math.cos(angle)*-r;
cy = Math.sin(angle)*r;
}
if(oev.clientX>obox.offsetLeft && oev.clientY>obox.offsetTop){
cx = Math.cos(angle)*r;
cy = Math.sin(angle)*r;
}
obox.style.top = 400+cy+'px';
obox.style.left = 400+cx+'px';
}
</script>
</html>【Recommended learning: javascript advanced tutorial】
The above is the detailed content of Does JavaScript support trigonometric functions?. For more information, please follow other related articles on the PHP Chinese website!
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
AI Hentai Generator
Generate AI Hentai for free.
Hot Article
Hot Tools
Notepad++7.3.1
Easy-to-use and free code editor
SublimeText3 Chinese version
Chinese version, very easy to use
Zend Studio 13.0.1
Powerful PHP integrated development environment
Dreamweaver CS6
Visual web development tools
SublimeText3 Mac version
God-level code editing software (SublimeText3)
Hot Topics
1378
52
How to implement an online speech recognition system using WebSocket and JavaScript
Dec 17, 2023 pm 02:54 PM
How to use WebSocket and JavaScript to implement an online speech recognition system Introduction: With the continuous development of technology, speech recognition technology has become an important part of the field of artificial intelligence. The online speech recognition system based on WebSocket and JavaScript has the characteristics of low latency, real-time and cross-platform, and has become a widely used solution. This article will introduce how to use WebSocket and JavaScript to implement an online speech recognition system.
WebSocket and JavaScript: key technologies for implementing real-time monitoring systems
Dec 17, 2023 pm 05:30 PM
WebSocket and JavaScript: Key technologies for realizing real-time monitoring systems Introduction: With the rapid development of Internet technology, real-time monitoring systems have been widely used in various fields. One of the key technologies to achieve real-time monitoring is the combination of WebSocket and JavaScript. This article will introduce the application of WebSocket and JavaScript in real-time monitoring systems, give code examples, and explain their implementation principles in detail. 1. WebSocket technology
How to use JavaScript and WebSocket to implement a real-time online ordering system
Dec 17, 2023 pm 12:09 PM
Introduction to how to use JavaScript and WebSocket to implement a real-time online ordering system: With the popularity of the Internet and the advancement of technology, more and more restaurants have begun to provide online ordering services. In order to implement a real-time online ordering system, we can use JavaScript and WebSocket technology. WebSocket is a full-duplex communication protocol based on the TCP protocol, which can realize real-time two-way communication between the client and the server. In the real-time online ordering system, when the user selects dishes and places an order
How to implement an online reservation system using WebSocket and JavaScript
Dec 17, 2023 am 09:39 AM
How to use WebSocket and JavaScript to implement an online reservation system. In today's digital era, more and more businesses and services need to provide online reservation functions. It is crucial to implement an efficient and real-time online reservation system. This article will introduce how to use WebSocket and JavaScript to implement an online reservation system, and provide specific code examples. 1. What is WebSocket? WebSocket is a full-duplex method on a single TCP connection.
JavaScript and WebSocket: Building an efficient real-time weather forecasting system
Dec 17, 2023 pm 05:13 PM
JavaScript and WebSocket: Building an efficient real-time weather forecast system Introduction: Today, the accuracy of weather forecasts is of great significance to daily life and decision-making. As technology develops, we can provide more accurate and reliable weather forecasts by obtaining weather data in real time. In this article, we will learn how to use JavaScript and WebSocket technology to build an efficient real-time weather forecast system. This article will demonstrate the implementation process through specific code examples. We
How to use insertBefore in javascript
Nov 24, 2023 am 11:56 AM
Usage: In JavaScript, the insertBefore() method is used to insert a new node in the DOM tree. This method requires two parameters: the new node to be inserted and the reference node (that is, the node where the new node will be inserted).
Simple JavaScript Tutorial: How to Get HTTP Status Code
Jan 05, 2024 pm 06:08 PM
JavaScript tutorial: How to get HTTP status code, specific code examples are required. Preface: In web development, data interaction with the server is often involved. When communicating with the server, we often need to obtain the returned HTTP status code to determine whether the operation is successful, and perform corresponding processing based on different status codes. This article will teach you how to use JavaScript to obtain HTTP status codes and provide some practical code examples. Using XMLHttpRequest
How to get HTTP status code in JavaScript the easy way
Jan 05, 2024 pm 01:37 PM
Introduction to the method of obtaining HTTP status code in JavaScript: In front-end development, we often need to deal with the interaction with the back-end interface, and HTTP status code is a very important part of it. Understanding and obtaining HTTP status codes helps us better handle the data returned by the interface. This article will introduce how to use JavaScript to obtain HTTP status codes and provide specific code examples. 1. What is HTTP status code? HTTP status code means that when the browser initiates a request to the server, the service
