经纬度距离转换
//
// main.c
// Distance
//
// Created by 1513 on 12-7-9.
// Copyright (c) 2012年 __MyCompanyName__. All rights reserved.
//
#include
#include
#define PI 3.1415926
#define EARTH_RADIUS 6378.137 //地球近似半径
double radian(double d);
double get_distance(double lat1, double lng1, double lat2, double lng2);
// 求弧度
double radian(double d)
{
return d * PI / 180.0; //角度1? = π / 180
}
//计算距离
double get_distance(double lat1, double lng1, double lat2, double lng2)
{
double radLat1 = radian(lat1);
double radLat2 = radian(lat2);
double a = radLat1 - radLat2;
double b = radian(lng1) - radian(lng2);
double dst = 2 * asin((sqrt(pow(sin(a / 2), 2) + cos(radLat1) * cos(radLat2) * pow(sin(b / 2), 2) )));
dst = dst * EARTH_RADIUS;
dst= round(dst * 10000) / 10000;
return dst;
}
int main (int argc, const char * argv[])
{
double lat1 = 39.90744;
double lng1 = 116.41615;//经度,纬度1
double lat2 = 39.90744;
double lng2 = 116.30746;//经度,纬度2
// insert code here...
double dst = get_distance(lat1, lng1, lat2, lng2);
printf("dst = %0.3fkm\n", dst); //dst = 9.281km
return 0;
}