Calculate the distance based on the longitude and latitude, and convert Baidu to GPS coordinates (PHP version)

Calculate the distance according to the latitude and longitude, and convert Baidu to GPS coordinates (PHP version) & lt ;? Php // Convert Baidu coordinates to GPS coordinates $ lnglat = '2017. 437518, 31.224665 '; functionFromBaiduToGpsXY ($ lnglat) {// longitude, latitude $ lnglat = exp calculate the distance formula based on latitude and longitude, Baidu convert coordinates to GPS coordinates (PHP version)

 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; // longitude, latitude} else return $ lnglat ;} /*************************************** * *****/function fn_rad ($ d) {return $ d * pi ()/180.0;} // function P2PDistance ($ latlng1, $ latlng2) {// latitude 1, Longitude 1 ~ Latitude 2, longitude 2 $ latlng1 = explode (',', $ latlng1); $ latlng2 = explode (',', $ latlng2); list ($ lat1, $ lng1) = $ latlng1; list ($ lat2, $ lng2) = $ latlng2; $ EARTH_RADIUS = 6378.137; $ radLat1 = fn_rad ($ lat1); $ radLat2 = fn_rad ($ lat2 ); $ a = $ radLat1-$ radLat2; $ B = fn_rad ($ lng1)-fn_rad ($ lng2 ); $ s = 2 * asin (sqrt (pow (sin ($ a/2), 2) + cos ($ radLat1) * cos ($ radLat2) * pow (sin ($ B/2), 2); $ s = $ s * $ EARTH_RADIUS; $ s = round ($ s * 10000)/10000; return number_format ($ s, 2);} echo 'Baidu coordinate: ', $ lnglat ,'

',' GPS coordinates after conversion: ', FromBaiduToGpsXY ($ lnglat ),'

'; Echo' distance before conversion: ', P2PDistance ('31. 224286666667,121.420675', '31. 224665,121.437518 '),'
'; Echo' distance after conversion: ', P2PDistance ('31. 100', '31. 100');?>