PHP obtains the range coordinate data based on the longitude and latitude.

PHP obtains the data calculation range of the range coordinate based on the longitude and latitude, and can search users.

// Computing range, which can be used for searching users

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Function GetRange ($ lat, $ lon, $ raidus) {// calculate the latitude $ degree = (24901 1609)/360.0; $ dpmLat = 1/$ degree; $ radiusLat = $ dpmLat $ raidus; $ minLat = $ lat $ radiusLat; // obtain the minimum latitude. $ maxLat = $ lat + $ radiusLat; // obtain the maximum latitude // calculate the longitude $ mpdLng = $ degree cos ($ lat (PI/180); $ dpmLng = 1/$ mpdLng; $ radiusLng = $ dpmLng $ raidus; $ minLng = $ lon $ radiusLng; // obtain the minimum longitude $ maxLng = $ lon + $ radiusLng; // obtain the maximum longitude // range $ range = array ('minlat' => $ minLat, 'maxlat' => $ maxLat, 'minlon '=> $ minLng, 'maxlon '=> $ maxLng); return $ range ;}

Obtain all data within the specified range.

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$ Result = GetRange (110.325945, 20.031541, 5000); $ where = "('jingdu' ". $ result ['minlat']. "and ". $ result ['maxlat']. ") and ('weidu' ". $ result ['minlon ']. "and ". $ result ['maxlon ']. ")"; $ query = $ db> query ("select from ". DB_PRE. "hospital where $ where order BY id DESC"); while ($ row = $ db> fetch_array ($ query )) {$ list [] = $ row ['all _ name'];} print_r ($ list );