地图上半径内的经纬度

    /*
     * 地图上半径内的经纬度
     * @param lat 纬度 lon 经度 raidus 单位米
     */
    function getAround($lat,$lon,$raidus){
        $raidus = empty($raidus)?3000:$raidus;
        $PI = 3.14159265;
        $latitude = $lat;
        $longitude = $lon;
        $degree = (24901*1609)/360.0;
        $raidusMile = $raidus;
        $dpmLat = 1/$degree;
        $radiusLat = $dpmLat*$raidusMile;
        $minLat = $latitude-$radiusLat;
        $maxLat = $latitude + $radiusLat;
        $mpdLng = $degree*cos($latitude * ($PI/180));
        $dpmLng = 1 / $mpdLng;
        $radiusLng = $dpmLng*$raidusMile;
        $minLng = $longitude - $radiusLng;
        $maxLng = $longitude + $radiusLng;
        $data[‘minLat‘] = $minLat;
        $data[‘maxLat‘] = $maxLat;
        $data[‘minLng‘] = $minLng;
        $data[‘maxLng‘] = $maxLng;
        return $data;
    }