/**  * 计算两个坐标之间的距离(米)  * @param float $fP1Lat 起点(纬度)  * @param float $fP1Lon 起点(经度)  * @param float $fP2Lat 终点(纬度)  * @param float $fP2Lon 终点(经度)  * @return int  */ function distanceBetween($fP1Lat, $fP1Lon, $fP2Lat, $fP2Lon){     $fEARTH_RADIUS = 6378137;     //角度换算成弧度     $fRadLon1 = deg2rad($fP1Lon);     $fRadLon2 = deg2rad($fP2Lon);     $fRadLat1 = deg2rad($fP1Lat);     $fRadLat2 = deg2rad($fP2Lat);     //计算经纬度的差值     $fD1 = abs($fRadLat1 - $fRadLat2);     $fD2 = abs($fRadLon1 - $fRadLon2);     //距离计算     $fP = pow(sin($fD1/2), 2) +           cos($fRadLat1) * cos($fRadLat2) * pow(sin($fD2/2), 2);     return intval($fEARTH_RADIUS * 2 * asin(sqrt($fP)) + 0.5); } /**  * 百度坐标系转换成标准GPS坐系  * @param float $lnglat 坐标(如:106.426, 29.553404)  * @return string 转换后的标准GPS值:  */ function BD09LLtoWGS84($fLng, $fLat){ // 经度,纬度     $lnglat = explode(',', $lnglat);     list($x,$y) = $lnglat;     $Baidu_Server = "http://api.map.baidu.com/ag/coord/convert?from=0&to=4&x={$x}&y={$y}";     $result = @file_get_contents($Baidu_Server);     $json = json_decode($result);     if($json->error == 0){         $bx = base64_decode($json->x);         $by = base64_decode($json->y);         $GPS_x = 2 * $x - $bx;         $GPS_y = 2 * $y - $by;         return $GPS_x.','.$GPS_y;//经度,纬度     }else         return $lnglat; }