Calculating heading between two latitude and longitude in iPhone

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how to calculate the current speed and average speed of user travelling from current location to particular loaction in map in iphone

I have a situation where i should not use CLLocationManger class.I am given with two latitude and longitude values(a source and destination).I want find out the heading from these two points in iPhone.How can i do this?

I referred to the formula in this link.But i am not able to get the heading.Please any body help me in calculating the heading

Thank you all in advance.

Why is this question considered duplicate? The linked duplicate question does not calculate heading. — franklins, Nov 16 '12 at 16:59

score 1 · Accepted Answer · answered May 15 '11 at 07:48

1

Here you are. These are 2 functions you can use to calculate distance between 2 Locations.

-(float)getDistanceInKm:(CLLocation *)newLocation fromLocation:(CLLocation *)oldLocation
{
    float lat1,lon1,lat2,lon2;

    lat1 = newLocation.coordinate.latitude  * M_PI / 180;
    lon1 = newLocation.coordinate.longitude * M_PI / 180;

    lat2 = oldLocation.coordinate.latitude  * M_PI / 180;   
    lon2 = oldLocation.coordinate.longitude * M_PI / 180;

    float R = 6371; // km
    float dLat = lat2-lat1;
    float dLon = lon2-lon1; 

    float a = sin(dLat/2) * sin(dLat/2) + cos(lat1) * cos(lat2) * sin(dLon/2) * sin(dLon/2); 
    float c = 2 * atan2(sqrt(a), sqrt(1-a)); 
    float d = R * c;

    NSLog(@"Kms-->%f",d);

    return d;
}

-(float)getDistanceInMiles:(CLLocation *)newLocation fromLocation:(CLLocation *)oldLocation
{
    float lat1,lon1,lat2,lon2;

    lat1 = newLocation.coordinate.latitude  * M_PI / 180;
    lon1 = newLocation.coordinate.longitude * M_PI / 180;

    lat2 = oldLocation.coordinate.latitude  * M_PI / 180;   
    lon2 = oldLocation.coordinate.longitude * M_PI / 180;

    float R = 3963; // km
    float dLat = lat2-lat1;
    float dLon = lon2-lon1; 

    float a = sin(dLat/2) * sin(dLat/2) + cos(lat1) * cos(lat2) * sin(dLon/2) * sin(dLon/2); 
    float c = 2 * atan2(sqrt(a), sqrt(1-a)); 
    float d = R * c;

    NSLog(@"Miles-->%f",d);

    return d;
}

Hope it helps.

answered May 15 '11 at 07:48

Janak Nirmal

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Hi Jennis,thanks for your reply.But here you have used CLLocation Manager class.But my situation is i just have only two set of latitude and longitude which comes from the webservice.I want to findout the distance,heading and bearing...Please let me know your thoughts.. – Sankar Chandra Bose May 15 '11 at 08:28
@Sankar you can create CLLocation object with the help of following statement. CLLocation *yourLoc = [[CLLocation alloc] initWithLatitude:yourLatitude longitude:yourLongitude]; – Janak Nirmal May 16 '11 at 04:05
Thanks Jennis...I hope this will work..I try to implement this and let you know the feedback..Thanks a lot Jennis for your response – Sankar Chandra Bose May 16 '11 at 08:40
@Sankar If it works according to your requirement please mark this as accepted solution or upvote for answer. – Janak Nirmal May 16 '11 at 08:56
Ya sure man i will definitely do that... – Sankar Chandra Bose May 16 '11 at 08:59
2

hey i think what you need is a function to get the heading from two locations. Given an object that has lat,lng attirbutes you could do this: -(float)getHeadingForDirectionToCoordinate:(double)fromLat fromLng:(double)fromLng { float tLat = radians([self.lat floatValue]); float tLng = radians([self.lng floatValue]); float fLat = radians(fromLat); float fLng = radians(fromLng); float brng = atan2(sin(tLng-fLng)*cos(tLat), cos(fLat)*sin(tLat)-sin(fLat)*cos(tLat)*cos(tLng-fLng)); return = fmodf((degrees(brng) + 360), 360); } if someone could reopen the question... – ugiflezet Aug 07 '11 at 17:03

Calculating heading between two latitude and longitude in iPhone

1 Answers1