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javascript - 如何计算多个航点之间的航点？

问题描述

例如，我有一个包含 3 个航点的数组： [ [ 526, 1573, 24 ], [ 2224, 809, -1546 ], [ 6869, 96, -3074 ] ]

我也知道我想休息让我们说n到达第一个和最后一个航路点之间的时间。所以最后我想要一个n点数组。

我如何n在 JS 中找到那些休息点？

提前致谢！

编辑：注意这不是一个单一的对象！想象每个轴都是一个人。他们必须在相同的时间和相同的时间停止，但显然他们不必在同一个地方。

标签： javascriptarraysvector

解决方案

您想使用线性插值。

一个简单的例子：

const POINTS = [ [ 526, 1573, 24 ], [ 2224, 809, -1546 ], [ 6869, 96, -3074 ] ];
const N = 10;

function getDistance(point1, point2) {
    // speed in 3d space is mutated according only to the X distance,
    // to keep speed constant in X dimension
    return Math.abs(point1[0] - point2[0]);
}

function go(points, n) {
    const pointDistances = points.slice(1).map((point, index) => getDistance(points[index], point));

    const fullDistance = pointDistances.reduce((sum, distance) => sum + distance, 0);

    const distancePerSection = fullDistance / n;

    return points.slice(1)
        .reduce((last, point, index) => {
            const thisDistance = pointDistances[index];

            const numRestPoints = Math.max(0, Math.floor(thisDistance / distancePerSection) - 1);

            if (!numRestPoints) {
                return last.concat([point]);
            }

            const thisYVector = point[1] - points[index][1];
            const thisZVector = point[2] - points[index][2];

            return last.concat(new Array(numRestPoints).fill(0)
                .reduce((section, item, restIndex) => {
                    return section.concat([[
                        points[index][0] + (restIndex + 1) * distancePerSection,
                        points[index][1] + (restIndex + 1) * thisYVector * distancePerSection / thisDistance,
                        points[index][2] + (restIndex + 1) * thisZVector * distancePerSection / thisDistance
                    ]]);
                }, [])
                .concat([point])
            );

        }, points.slice(0, 1));
}

function test() {
    const result = go(POINTS, N);

    if (result.length !== N) {
        throw new Error('Must be N length');
    }

    if (!result[0].every((value, index) => value === POINTS[0][index])) {
        throw new Error('Doesn\'t start at the first point');
    }
    if (!result[N - 1].every((value, index) => value === POINTS[POINTS.length - 1][index])) {
        throw new Error('Doesn\'t end at the last point');
    }

    if (!POINTS.slice(1, N - 1).every(point =>
        result.some(resultPoint => resultPoint.every((value, index) => value === point[index]))
    )) {
        throw new Error('Doesn\'t go through every provided point');
    }

    console.log(result.slice(1).map((point, index) => getDistance(point, result[index])));

    console.log('The result passed the tests!');
    console.log(JSON.stringify(result, null, 2));
}

test();

我基本上是在浏览点列表，并确定它们之间是否应该存在任何休息点，如果存在则插入它们。

如果您想进一步澄清，请发表评论！

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