JavaScript implements the arithmetic square root algorithm-super simple code _ javascript skills

There are many ways to implement the square root of Arithmetic. This article is an arithmetic square root algorithm implemented by JavaScript. the code is super simple and super-manageable, if you are interested, I will study it with the little editor of my feet. a few days ago, I saw a square root source code from Raytheon. The principles are described in many aspects and I will not go into details.

The source code is written in C language. after thinking about it, I found that such an algorithm can also be completed in javascript.

Function InvSqrt (x) {var h = 0.5 * x; var B = new ArrayBuffer (4); var d = new DataView (B, 0); d. setFloat32 (0, x); var I = d. getInt32 (0); I = 0x5f375a86-(I> 1); d. setInt32 (0, I); var r = d. getFloat32 (0); r = r * (1.5-h * r); return r ;}

Test:

Console. time ("t"); for (var I = 0; I <10000000; I ++) {InvSqrt (I);} console. timeEnd ("t"); console. time ("t"); for (var I = 0; I <10000000; I ++) {1/Math. sqrt (I);} console. timeEnd ("t"); VM2303: 18 t: 33438.000msVM2303: 24 t: 16720.000 ms

Although the results are still slower than the system database, and the accuracy is inherently low. But I'm very satisfied.

The above describes how to use javascript to implement the arithmetic square root algorithm. the code is very simple. come and learn it .!