基于概率和百分比的返回值

Question

关于这些例子，你知道我如何实现概率吗。

let directions = [
    {
        1: {
            left: {
                successRate: 1,
                direction: 0
            },
            top: {
                successRate: 35,
                direction: 1
            },
            right: {
                successRate: 15,
                direction: 2
            },
            bottom: {
                successRate: 5,
                direction: 3
            }
        },
    }
]

1. 应该在属性中循环
2. 在顶部、右侧、底部和左侧循环以检索其成功率值
3. 随机检索一个方向，根据它的成功率（也就是它的概率）与所有东西进行比较。概率越高的人被呼叫的几率越高

程序在setInterval内，每次interval循环时，都会打印值。我尝试了很多不同的方法，但我想不出来。

更新对于我目前遇到的实际问题。

您可以忽略“未找到”。它只是一个随机字符串。数字根据概率随机生成，但在setInterval函数中调用x次后，它变得“未定义”。

代码：

let directions = [
    {
        1: {
            left: {
                successRate: 5,
                direction: 0
            },
            top: {
                successRate: 3,
                direction: 1
            },
            right: {
                successRate: 10,
                direction: 2
            },
            bottom: {
                successRate: 30,
                direction: 3
            }
        },
    }
]

var chances = [40, 30, 15, 10, 5]; 
let items = Object.values(directions[0][1]);

function chooseWeighted(items, chances) {
    var sum = chances.reduce((acc, el) => acc + el, 0);
    var acc = 0;
    chances = chances.map(el => (acc = el + acc));
    var rand = Math.random() * sum;
    return items[chances.filter(el => el <= rand).length];
}

function scanPlayerArea(){
    console.log(chooseWeighted(items, chances).direction);
}

输出：

Not found.
1
Not found.
0
Not found.
0
Not found.
2
Not found.
0
Not found.
1
Not found.
1
Not found.
0
Not found.
0
Not found.
C:\Users\Name\Desktop\Script\file.js:1351
    dir = chooseWeighted(items, chances).direction;
                                        ^

TypeError: Cannot read property 'direction' of undefined
    at scanPlayerArea (C:\Users\Name\Desktop\Script\file.js:1351:41)
    at Timeout._onTimeout (C:\Users\Name\Desktop\Script\file.js:1633:6)
    at listOnTimeout (internal/timers.js:549:17)
    at processTimers (internal/timers.js:492:7)

C:\Users\Name\Desktop\Script>

循环：

setInterval(function(){
    scanPlayerArea()
}, 50);

Answer 1

如果我理解正确，您希望在每次迭代中根据成功率属性上设置的概率拾取随机方向。如果是这样，我可以想到一种方法：

let directions = [
    {
        1: {
            left: {
                successRate: 5,
                direction: 0
            },
            top: {
                successRate: 3,
                direction: 1
            },
            right: {
                successRate: 10,
                direction: 2
            },
            bottom: {
                successRate: 30,
                direction: 3
            }
        },
    }
];

const items = directions[0][1];

// Calculate the total rate 100%, just a sum of all the items
let totalRate = 0;
for (var key of Object.keys(items)) {
    totalRate += items[key].successRate;
}

// Calculate the coeficient of success rate for each item and save it in items
let lastCoef = 0;
for (var key of Object.keys(items)) {
  items[key].coef = lastCoef + items[key].successRate / totalRate;
  lastCoef = items[key].coef;
  console.log(key + ' coeficient: ' + lastCoef);
}

function chooseWeighted(items) {
  const randomNum = Math.random();
  for (var key of Object.keys(items)) {
    if(randomNum < items[key].coef) {
      return key;
    }
  }
}

function scanPlayerArea(){
  console.log(chooseWeighted(items));
}

setInterval(function(){
  scanPlayerArea();
}, 1000);