MathUtils.ts
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/*
* name;
*/
export default class MathUtils {
/**
* 获取从min-max之间的值，包括min max
* @param min
* @param max
*/
static rang(min, max) {
return Math.random() * (max - min) + min;
}
static random(min: number, max: number) {
min = Math.min(min, max);
max = Math.max(min, max);
var range: number = max - min;
return min + Math.random() * range;
}
static randomInt(min: number, max: number) {
return Math.floor(this.random(min, max + 1));
}
/**
* 概率随机
* @param arr
*/
public static getRandomResult(arr: number[]): number {
var leng = 0;
//获取总数
for (var i = 0; i < arr.length; i++) {
leng += arr[i]
}
for (var i = 0; i < arr.length; i++) {
//获取 0-总数 之间的一个随随机整数
var random = Math.random() * leng
//如果在当前的概率范围内,得到的就是当前概率
if (random < arr[i]) {
return i
}
else {
//否则减去当前的概率范围,进入下一轮循环
leng -= arr[i]
}
}
}
/**
* 计算两点距离
*/
public static cacuDis(x1: number, y1: number, x2: number, y2: number): number {
return Math.sqrt(Math.pow(x2 - x1, 2) + Math.pow(y2 - y1, 2));
}
static cacuAngle(x1: number, y1: number, x2: number, y2: number) {
return Math.atan2(y2 - y1, x2 - x1) / Math.PI * 180;
}
/**
* 求余
* @param value
* @param max
*/
public static cacuSurplus(value: number, max: number) {
while (value < 0) {
value += max;
}
while (value >= max) {
value -= max;
}
return value;
}
static between(value: number, min: number, max: number) {
if (min > max) {
let temp = min;
min = max;
max = temp;
}
return Math.max(min, Math.min(value, max));
}
static subPoint(value: number, cnt: number) {
let s = Math.pow(10, cnt);
return Math.round(value * s) / s;
}
}