iOS根据2个经纬度计算距离

来源：互联网发布：第三次农业普查数据编辑：程序博客网时间：2024/06/05 05:45
#pragma mark - calculate distance  根据2个经纬度计算距离#define PI 3.14159265358979323+(double) CalculationDistanceOther_Lon1:(double)lon1 Other_Lat1:(double)lat1 self_Lon2:(double)lon2 self_Lat2:(double)lat2{    double er = 6371229; // 6378700.0f;    //ave. radius = 6371.315 (someone said more accurate is 6366.707)    //equatorial radius = 6378.388    //nautical mile = 1.15078    double radlat1 = PI*lat1/180.0f;    double radlat2 = PI*lat2/180.0f;    //now long.    double radlong1 = PI*lon1/180.0f;    double radlong2 = PI*lon2/180.0f;    if( radlat1 < 0 ) radlat1 = PI/2 + fabs(radlat1);// south    if( radlat1 > 0 ) radlat1 = PI/2 - fabs(radlat1);// north    if( radlong1 < 0 ) radlong1 = PI*2 - fabs(radlong1);//west    if( radlat2 < 0 ) radlat2 = PI/2 + fabs(radlat2);// south    if( radlat2 > 0 ) radlat2 = PI/2 - fabs(radlat2);// north    if( radlong2 < 0 ) radlong2 = PI*2 - fabs(radlong2);// west    //spherical coordinates x=r*cos(ag)sin(at), y=r*sin(ag)*sin(at), z=r*cos(at)    //zero ag is up so reverse lat    double x1 = er * cos(radlong1) * sin(radlat1);    double y1 = er * sin(radlong1) * sin(radlat1);    double z1 = er * cos(radlat1);    double x2 = er * cos(radlong2) * sin(radlat2);    double y2 = er * sin(radlong2) * sin(radlat2);    double z2 = er * cos(radlat2);    double d = sqrt((x1-x2)*(x1-x2)+(y1-y2)*(y1-y2)+(z1-z2)*(z1-z2));    //side, side, side, law of cosines and arccos    double theta = acos((er*er+er*er-d*d)/(2*er*er));    double dist  = theta*er;    return dist;}
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