javascript - 从度数中获取方向

Question

我构建了一个能够计算设备航向的小型指南针项目。所以我得到的是一个函数，它返回当前航向的 0° 和 360° 之间的值。

我想从这样的数组中获取当前航向方向的匹配值:(["North", "North-East", "East", "South-East", "South ", "西南", "西", "西北"])

(请记住:北 = 0°/359°)

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但是我不知道如何得到这样的结果，下面这几行是我到目前为止得到的所有结果，但它似乎不起作用:

var directions = ["North", "North-East", "East", "South-East", "South", "South-West", "West", "North-West"]

function getDirection(heading) {
   var index = Math.round((heading/8)/5,625)
   return directions[index]
}

任何帮助将不胜感激，在此先感谢。

Answer 1

此解决方案应考虑所有可能的情况:

var index = Math.round(((angle %= 360) < 0 ? angle + 360 : angle) / 45) % 8;

function getDirection(angle) {
    var directions = ['North', 'North-East', 'East', 'South-East', 'South', 'South-West', 'West', 'North-West'];
    var index = Math.round(((angle %= 360) < 0 ? angle + 360 : angle) / 45) % 8;
    return directions[index];
}

console.log( getDirection(0) );
console.log( getDirection(45) );
console.log( getDirection(180) );
console.log( getDirection(99) );
console.log( getDirection(275) );
console.log( getDirection(-120) );
console.log( getDirection(587) );