根据经纬度和半径来计算四个方向的距离

/**

* @param lat 纬度 lon 经度 raidus 单位米

* return minLat,minLng,maxLat,maxLng

*/

function getAround($lat,$lon,$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 - $radiusLat ;

$maxLng = $longitude + $radiusLng;

return array(

'var1'=>$minLng,

'var2'=>$maxLng,

'var3'=>$minLat,

'var4'=>$maxLat,

);

}

$squares = getAround($lang,$lat,400);

print_r($squares['var1']);

print_r($squares['var2']);

print_r($squares['var3']);

print_r($squares['var4']);