如何计算CLLocationDistance的中心坐标

我想计算我的位置和一些注释之间的中心点。到目前为止我已经这样做了：

CLLocation *myLoc = self.locMgr.location;

        MKPointAnnotation *middleAnnotation = [locationV.annotations objectAtIndex:locationV.annotations.count/2];

        CLLocation *someStuiodLoc = [[CLLocation alloc] initWithLatitude:middleAnnotation.coordinate.latitude longitude:middleAnnotation.coordinate.longitude];

        CLLocationDistance dist = [myLoc distanceFromLocation:someStuiodLoc];

如何计算“dist”的中心点/坐标？

#define ToRadian(x) ((x) * M_PI/180)
#define ToDegrees(x) ((x) * 180/M_PI)

+ (CLLocationCoordinate2D)midpointBetweenCoordinate:(CLLocationCoordinate2D)c1 andCoordinate:(CLLocationCoordinate2D)c2 
{ 
          c1.latitude = ToRadian(c1.latitude); 
          c2.latitude = ToRadian(c2.latitude);
          CLLocationDegrees dLon = ToRadian(c2.longitude - c1.longitude); 
          CLLocationDegrees bx = cos(c2.latitude) * cos(dLon); 
          CLLocationDegrees by = cos(c2.latitude) * sin(dLon);
          CLLocationDegrees latitude = atan2(sin(c1.latitude) + sin(c2.latitude), sqrt((cos(c1.latitude) + bx) * (cos(c1.latitude) + bx) + by*by));
          CLLocationDegrees longitude = ToRadian(c1.longitude) + atan2(by, cos(c1.latitude) + bx);

           CLLocationCoordinate2D midpointCoordinate; 
           midpointCoordinate.longitude = ToDegrees(longitude); 
           midpointCoordinate.latitude = ToDegrees(latitude);

           return midpointCoordinate;
}