编辑代码

//JSRUN引擎2.0，支持多达30种语言在线运行，全仿真在线交互输入输出。 // 定义常量
const PI = 3.1415926535897932384626;
const A = 6378245.0; // 长半轴
const EE = 0.00669342162296594323; // 扁率

// 判断是否在中国范围
function outOfChina(lat, lon) {
    return lon < 72.004 || lon > 137.8347 || lat < 0.8293 || lat > 55.8271;
}

// 将GCJ-02坐标转换为WGS-84坐标
function gcj02ToWgs84(lat, lon) {
    if (outOfChina(lat, lon)) {
        return { lat, lon };
    }

    let dLat = transformLat(lon - 105.0, lat - 35.0);
    let dLon = transformLon(lon - 105.0, lat - 35.0);
    const radLat = lat / 180.0 * PI;
    let magic = Math.sin(radLat);
    magic = 1 - EE * magic * magic;
    const sqrtMagic = Math.sqrt(magic);
    dLat = (dLat * 180.0) / ((A * (1 - EE)) / (magic * sqrtMagic) * PI);
    dLon = (dLon * 180.0) / (A / sqrtMagic * Math.cos(radLat) * PI);
    const mgLat = lat + dLat;
    const mgLon = lon + dLon;

    return {
        lat: lat * 2 - mgLat,
        lon: lon * 2 - mgLon
    };
}

// 纬度转换
function transformLat(x, y) {
    let ret = -100.0 + 2.0 * x + 3.0 * y + 0.2 * y * y + 0.1 * x * y + 0.2 * Math.sqrt(Math.abs(x));
    ret += (20.0 * Math.sin(6.0 * x * PI) + 20.0 * Math.sin(2.0 * x * PI)) * 2.0 / 3.0;
    ret += (20.0 * Math.sin(y * PI) + 40.0 * Math.sin(y / 3.0 * PI)) * 2.0 / 3.0;
    ret += (160.0 * Math.sin(y / 12.0 * PI) + 320 * Math.sin(y * PI / 30.0)) * 2.0 / 3.0;
    return ret;
}

// 经度转换
function transformLon(x, y) {
    let ret = 300.0 + x + 2.0 * y + 0.1 * x * x + 0.1 * x * y + 0.1 * Math.sqrt(Math.abs(x));
    ret += (20.0 * Math.sin(6.0 * x * PI) + 20.0 * Math.sin(2.0 * x * PI)) * 2.0 / 3.0;
    ret += (20.0 * Math.sin(x * PI) + 40.0 * Math.sin(x / 3.0 * PI)) * 2.0 / 3.0;
    ret += (150.0 * Math.sin(x / 12.0 * PI) + 300.0 * Math.sin(x / 30.0 * PI)) * 2.0 / 3.0;
    return ret;
}

// 测试转换 118.21667,37.16361
const gcjLat = 37.168711; // 示例：北京的GCJ-02坐标
const gcjLon = 118.219978;
const wgsCoord = gcj02ToWgs84(gcjLat, gcjLon);

console.log("GCJ-02坐标：", { lat: gcjLat, lon: gcjLon });
console.log("转换到近似CGCS2000（通过WGS-84）：", wgsCoord);