iOS根据2个经纬度计算距离 

 1 #pragma mark - calculate distance  根据2个经纬度计算距离
 2 
 3 #define PI 3.14159265358979323
 4 +(double) CalculationDistanceOther_Lon1:(double)lon1 Other_Lat1:(double)lat1 self_Lon2:(double)lon2 self_Lat2:(double)lat2{
 5     double er = 6371229; // 6378700.0f;
 6     //ave. radius = 6371.315 (someone said more accurate is 6366.707)
 7     //equatorial radius = 6378.388
 8     //nautical mile = 1.15078
 9     double radlat1 = PI*lat1/180.0f;
10     double radlat2 = PI*lat2/180.0f;
11     //now long.
12     double radlong1 = PI*lon1/180.0f;
13     double radlong2 = PI*lon2/180.0f;
14     if( radlat1 < 0 ) radlat1 = PI/2 + fabs(radlat1);// south
15     if( radlat1 > 0 ) radlat1 = PI/2 - fabs(radlat1);// north
16     if( radlong1 < 0 ) radlong1 = PI*2 - fabs(radlong1);//west
17     if( radlat2 < 0 ) radlat2 = PI/2 + fabs(radlat2);// south
18     if( radlat2 > 0 ) radlat2 = PI/2 - fabs(radlat2);// north
19     if( radlong2 < 0 ) radlong2 = PI*2 - fabs(radlong2);// west
20     //spherical coordinates x=r*cos(ag)sin(at), y=r*sin(ag)*sin(at), z=r*cos(at)
21     //zero ag is up so reverse lat
22     double x1 = er * cos(radlong1) * sin(radlat1);
23     double y1 = er * sin(radlong1) * sin(radlat1);
24     double z1 = er * cos(radlat1);
25     double x2 = er * cos(radlong2) * sin(radlat2);
26     double y2 = er * sin(radlong2) * sin(radlat2);
27     double z2 = er * cos(radlat2);
28     double d = sqrt((x1-x2)*(x1-x2)+(y1-y2)*(y1-y2)+(z1-z2)*(z1-z2));
29     //side, side, side, law of cosines and arccos
30     double theta = acos((er*er+er*er-d*d)/(2*er*er));
31     double dist  = theta*er;
32     return dist;
33 }

 

posted @ 2016-01-08 10:56  御剑青冥  阅读(223)  评论(0)    收藏  举报