Question

我对确定lat / lng位置是否在边界内并寻找算法建议感兴趣。（javascript或php）

这是我到目前为止所做的：

var lat = somelat;
var lng = somelng;

if (bounds.southWest.lat < lat && lat < bounds.northEast.lat && bounds.southWest.lng < lng && lng < bounds.northEast.lng) {
     'lat and lng in bounds
}

这会有效吗？感谢

Answer 1

您帖子中的简单比较适用于美国的坐标。但是，如果您想要一个可以安全检查国际日期变更线（经度为±180°）的解决方案：

function inBounds(point, bounds) {
    var eastBound = point.long < bounds.NE.long;
    var westBound = point.long > bounds.SW.long;
    var inLong;

    if (bounds.NE.long < bounds.SW.long) {
        inLong = eastBound || westBound;
    } else {
        inLong = eastBound && westBound;
    }

    var inLat = point.lat > bounds.SW.lat && point.lat < bounds.NE.lat;
    return inLat && inLong;
}

Answer 2

当你询问Javascript和PHP（我在PHP中需要它）时，我将CheeseWarlock的优秀答案转换为PHP。像往常一样，PHP不那么优雅。：）

function inBounds($pointLat, $pointLong, $boundsNElat, $boundsNElong, $boundsSWlat, $boundsSWlong) {
    $eastBound = $pointLong < $boundsNElong;
    $westBound = $pointLong > $boundsSWlong;

    if ($boundsNElong < $boundsSWlong) {
        $inLong = $eastBound || $westBound;
    } else {
        $inLong = $eastBound && $westBound;
    }

    $inLat = $pointLat > $boundsSWlat && $pointLat < $boundsNElat;
    return $inLat && $inLong;
}

Answer 3

这是我为MySQL修改的我的代码现在，它可以通过mysql查询直接检查我们的长纬度是否在界限内。

特别感谢CheeseWarlock和Chris Rae的解决方案先生

select inBounds("58.25173","-100.21041","89.71691425364952","180","-88.9294031317244","-180")

，您可以像这种方式在查询中调用此函数

DELIMITER $$
CREATE FUNCTION inBounds(pointLat FLOAT, pointLong FLOAT, boundsNElat FLOAT, boundsNElong FLOAT, boundsSWlat FLOAT, boundsSWlong FLOAT) RETURNS VARCHAR(30)
 BEGIN
  DECLARE westBound FLOAT ;
  DECLARE eastBound FLOAT ;
  DECLARE inLong FLOAT DEFAULT 0 ;
  DECLARE inLat FLOAT DEFAULT 0 ;
  IF (pointLong < boundsNElong) THEN 
    SET eastBound = 1;
  End if;
  IF (pointLong > boundsSWlong) THEN
    SET westBound = 1;
  End if;

  IF (boundsNElong < boundsSWlong) THEN
      IF (eastBound || westBound) THEN
         SET inLong = 1;
     END if;
  ELSE 
     IF (eastBound && westBound) THEN 
         SET inLong = 1;
     END IF;
  END IF;
  IF (pointLat > boundsSWlat && pointLat < boundsNElat) THEN
    SET inLat = 1;
  END IF;
  RETURN inLat && inLong;
END$$
DELIMITER ;

Answer 4

这是CheeseWarlock的Js答案的稍微优化的版本，它会短路。

const inBounds = (point, bounds) => {
    const inLat = point.lat > bounds.sw.lat && point.lat < bounds.ne.lat
    if (!inLat) return false

    const eastBound = point.lng < bounds.ne.lng
    const westBound = point.lng > bounds.sw.lng
    return (bounds.ne.lng < bounds.sw.lng)
        ? eastBound || westBound
        : eastBound && westBound
}

确定Bounds中的Lat / Lng

4 个答案: