how to find latitude and longitude of different locatoins in iphone - iphone

I am a new iphone developer,please help me to find out latitude and longitude of different locations(present location values, distance 10m form present locatoin)and find address of that locations using that latitude and longituse values.

using mapkit framework you can find the current location along with near by location with their latitude & longitude
CLLocationCoordinate2D location;
location = [mMapView.userLocation coordinate];
if(iLat && iLng) {
location.latitude = [iLat floatValue];
location.longitude = [iLng floatValue];
}

In order to find out lat & long use this link with complete instruction & sample
http://www.switchonthecode.com/tutorials/getting-your-location-in-an-iphone-application
And in order to get location address using latitude & longitude this can be done by MKReverseGeoCoder.... get in detail using following link
http://blog.objectgraph.com/index.php/2009/04/03/iphone-sdk-30-playing-with-map-kit-part-2/

If your new new to Iphone development, you might wanna return that phone and start developing on Android!
Na just kidding, this will work indeed:
CLLocationCoordinate2D location; location = [mMapView.userLocation coordinate];
if(iLat && iLng) {
location.latitude = [iLat floatValue];
location.longitude = [iLng floatValue];
}

What you want to do is called reverse geocoding. On iOS, this is easily done using MapKit's MKReverseGeocoder.

Here's what you need to do:
First, check if location services is enabled:
if ([CLLocationManager locationServicesEnabled])
[self findUserLocation];
Then in your findUserLocation method, instantiate your CLLocationManager and start receiving updates:
- (void)findUserLocation
{
CLLocationManager *locationManager_ = [[CLLocationManager alloc] init];
locationManager.delegate = self;
locationManager.desiredAccuracy = kCLLocationAccuracy{ChooseYourOptionHere};
[locationManager startUpdatingLocation];
}
You then implement this delegate method, which will get called every time an update is received. Check the current location's accuracy against your desired accuracy (set above), center the map if you are happy with it AND don't forget to stop the location manager from receiving updates:
- (void)locationManager:(CLLocationManager *)manager didUpdateToLocation:(CLLocation *)newLocation fromLocation:(CLLocation *)oldLocation
{
if ([newLocation horizontalAccuracy] < [manager desiredAccuracy])
{
// Accuracy is good enough, let's reverse geocode it
[manager stopUpdatingLocation];
[self reverseGeocodeWithCoordinate:newLocation.coordinate];
}
// else keep trying...
}
Once you're happy with the location accuracy, you can start the reverse geocoding process:
- (void)reverseGeocodeWithCoordinate:(CLLocationCoordinate*)coordinate
{
MKReverseGeocoder *geocoder = [[MKReverseGeocoder alloc] initWithCoordinate:coordinate];
geocoder.delegate = self;
[geocoder start];
}
And you will receive the response via delegate methods:
- (void)reverseGeocoder:(MKReverseGeocoder *)geocoder didFailWithError:(NSError *)error
{
geocoder.delegate = nil;
[geocoder autorelease];
// Reverse geocode failed, do something
}
- (void)reverseGeocoder:(MKReverseGeocoder *)geocoder didFindPlacemark:(MKPlacemark *)placemark
{
geocoder.delegate = nil;
[geocoder autorelease];
// Reverse geocode worked, do something...
}

Related

Incorrect distance and route found in my walking/running app

I am working on this walking/running app which calculates distance in meters and records lat-long for further use. Now when I calculate distance I get incorrect distance every time. I have compared it with other running apps and they generally show different distance than my distance.
Here is the code that I am using:
#define kDesiredAccuracy 5.0f
self.locationManager = [[CLLocationManager alloc] init];
self.locationManager.desiredAccuracy = kCLLocationAccuracyBestForNavigation;
self.locationManager.distanceFilter = kDesiredAccuracy;
_routes = [[NSMutableArray alloc] init];
lastKnownLocation = nil;
-(void)locationManager:(CLLocationManager *)manager didUpdateToLocation:(CLLocation *)newLocation fromLocation:(CLLocation *)oldLocation
{
// return if accuracy is less than 0 or is greater than desired accuracy.
if (newLocation.horizontalAccuracy < 0)
{
return;
}
if(newLocation.horizontalAccuracy > kDesiredAccuracy)
{
return;
}
NSTimeInterval locationAge = -[newLocation.timestamp timeIntervalSinceNow];
CLLocationSpeed speed = [newLocation speed];
// return if stale data or user is not moving
if (locationAge > 5.0 || speed <= 0) return;
//return if first location is found
if(lastKnownLocation == nil)
{
lastKnownLocation = newLocation;
return;
}
CLLocationDistance distance = [newLocation distanceFromLocation:(self.pramDistance > 0)?lastKnownLocation:oldLocation];
if(distance > 0)
{
// save distance for future use
NSMutableDictionary *dict=[[NSMutableDictionary alloc] init];
[dict setObject:[NSString stringWithFormat:#"%g", newLocation.coordinate.latitude] forKey:#"latitude"];
[dict setObject:[NSString stringWithFormat:#"%g", newLocation.coordinate.longitude] forKey:#"longtitude"];
[dict setObject:[NSString stringWithFormat:#"%f",distance] forKey:#"distance"];
[_routes addObject:dict];
// add distance to total distance.
self.pramDistance += distance;
}
}
Once user finishes walking/running I draw rout of walk/run on map view. For this purpose I simply draw a ploy line over MKMapView using all the recorded locations.
The map view shows zig-zag line for route and distance is always incorrect. Please suggest me where I am doing wrong and what should I amend to make it work proper?
Here is the comparison (left one is other's app and right one is mine):
Try this,
Import CLLocationManagerDelegate,
CLLocation *currentLocation = self.currentLocation;
float distanceMile = [currentLocation distanceFromLocation:[[CLLocation alloc] initWithLatitude:latitude longitude:longitude]]/1609.34;
-(void)postCurrentLocationOfDevice
{
self.locationManager = [[CLLocationManager alloc] init];
self.locationManager.distanceFilter = kCLDistanceFilterNone;
self.locationManager.desiredAccuracy = kCLLocationAccuracyBest;
[self.locationManager startUpdatingLocation];
self.locationManager.delegate = self;
}
-(void)locationManager:(CLLocationManager *)manager didUpdateLocations:(NSArray *)locations
{
self.currentLocation = [locations objectAtIndex:0];
[self.locationManager stopUpdatingLocation];
}
-(void)locationManager:(CLLocationManager *)manager didUpdateToLocation:(CLLocation *)newLocation fromLocation:(CLLocation *)oldLocation
{
self.currentLocation = newLocation;
[self.locationManager stopUpdatingLocation];
}
Though I didn't get much of the help here, I found some help and idea in this question: Corelocation incorrect distances
What I did to fix the problem is:
I stored recent 5 locations in an array.
Once 5 items are stored in the array, I checked for the nearest location.
After getting nearest location I calculated distance between last best location and stored new location in last best location.
P.S.: My code is messy and naming conventions are not that generic, that's why I am not posting my code here.

Cannot get GPS location on iPhone

My app runs perfectly on the simulator and everything works fine. But now i wanted to thest it on my iPhone and i found out that the GPS funcution don't work.
Here is my code.
[super viewDidLoad];
//eigener Standort
locationManager = [[CLLocationManager alloc] init];
locationManager.delegate = self;
locationManager.distanceFilter = kCLDistanceFilterNone; // whenever we move
locationManager.desiredAccuracy = kCLLocationAccuracyHundredMeters; // 100 m
[locationManager startUpdatingLocation];
}
- (void)locationManager:(CLLocationManager *)manager
didUpdateToLocation:(CLLocation *)newLocation
fromLocation:(CLLocation *)oldLocation
{
eigLat = newLocation.coordinate.latitude;
eigLon = newLocation.coordinate.longitude;
eigLatString = [NSString stringWithFormat:#"%f", eigLat];
eigLonString = [NSString stringWithFormat:#"%f", eigLon];
}
And till now everything is fine. If i use NSLog i get the right coordinates.
But then i want to use my coordinates here:
- (void)connectionDidFinishLoading:(NSURLConnection *)connection
{
[UIApplication sharedApplication].networkActivityIndicatorVisible = NO;
news = [NSJSONSerialization JSONObjectWithData:data options:NSJSONReadingMutableContainers error:NULL];
for (x=0; x<[news count]; x++)
{
//Berechnung der Entfernung
erdradius = 6371.1;
//Koordinaten von Datenbank in String schreiben
NSString *latitude = [[news objectAtIndex:x] objectForKey:#"Latitude"];
NSString *longitude = [[news objectAtIndex:x] objectForKey:#"Longitude"];
entfernung = 0;
double lat1 = eigLat; //eigener Standort Latitude
double long1 = eigLon; //eigener Standort Longitude
double lat2 = [latitude doubleValue]; //Standort Heurigen Latitude
double long2 = [longitude doubleValue]; //Standort Heurigen Longitude
And there I get everytime 0 for lat1 and lat2. But only if I Run the App on the iPhone. On the Simulator it works fine.
Does someone know why this could be?
The problem is that you did not get yet a GPS location in real world, so
your method connectionDidFinishLoading() is called before didUpdateToLocation() was called.
Therefoe eighValue is still 0.
Check first for valid lat and longitude:
if both are 0 then you did not get a location.
I think that you must change the logic of your program code,
you have to either
1) wait till you have a location, and then start the
connection such that connectionDidFinishLoading is called after you have a GPS coordinate.
Or
2) you store the coordinate result of the network connection, and calculate when you got your first coordinate

best way to get changed location iPhone sdk?

My ultimate goal is that i need to send lat and logitude to web server, every time when location changes.
I am using below code for sending lat and longitude of a device to a web server after every 2 minutes but it is not giving sometimes correct latitude and longitude as location changes.
- (void)locationManager:(CLLocationManager *)manager didUpdateToLocation:(CLLocation
*)newLocation fromLocation:(CLLocation *)oldLocation
{
NSTimeInterval locationAge = -[newLocation.timestamp timeIntervalSinceNow];
NSLog(#"Location Age%#",[NSString stringWithFormat:#"%d",locationAge]);
if (locationAge > 5) return;
// test that the horizontal accuracy does not indicate an invalid measurement
if (newLocation.horizontalAccuracy < 0) return;
NSString *stringUrl;
// BOOL check = FALSE;
NSLog(#"Before condition condition");
if(bestEffortAtLocation == nil || bestEffortAtLocation.horizontalAccuracy > newLocation.horizontalAccuracy){
NSLog(#"condition");
self.bestEffortAtLocation = newLocation;
if (newLocation.horizontalAccuracy <= locmanager.desiredAccuracy) {
// we have a measurement that meets our requirements, so we can stop updating the location
// IMPORTANT!!! Minimize power usage by stopping the location manager as soon as possible.
[locmanager stopUpdatingLocation];
locmanager.delegate = nil;
}
//check = TRUE;
}
stringUrl = [NSString stringWithFormat:URLSAVELAT,stringUserId,[NSString stringWithFormat:#"%g",self.bestEffortAtLocation.coordinate.latitude],[NSString stringWithFormat:#"%g",self.bestEffortAtLocation.coordinate.longitude]];}
For location manager i am using below code
{
locmanager = [[CLLocationManager alloc] init];
[locmanager setDelegate:self];
locmanager.distanceFilter = 10.0;
//locmanager.distanceFilter = kCLDistanceFilterNone;
[locmanager setDesiredAccuracy:kCLLocationAccuracyBest];
[locmanager startUpdatingLocation];
}
Any,even small help would be appreciated, Thank u in advance
You should use the location update call backs from the API and use updateLocation method:
- (void)locationManager:(CLLocationManager *)manager didUpdateToLocation:(CLLocation *)newLocation fromLocation:(CLLocation *)oldLocation {
if([self.delegate conformsToProtocol:#protocol(CoreLocationControllerDelegate)]) {
[self.delegate locationUpdate:newLocation];
}
}
Then in the viewcontroller do this:
- (void)locationUpdate:(CLLocation *)location {
//DO WHATEVER YOU WANT HERE, INCLUDING SENDING TO SERVER
}
You also need to define two protocol methods, one of which is the locationUpdate:
#protocol CoreLocationControllerDelegate
#required
- (void)locationUpdate:(CLLocation *)location;
- (void)locationError:(NSError *)error;
#end
I would not recommend doing all that you do in the didUpdateLocation: method.

how to find latitude and longitude in iphone4.0?

i am new to iphone
by using CLLocation i can find latitude and longitude but it is not working in iphonesimulater4.0 working in 3.2.1,please any one tell me how to calculate latitude & longitude in iphone4.0.
Thanks in advance
CLLocationCoordinate2D location =
[[[mapview userLocation] location] coordinate];
//NSLog(#"Location found from Map: %f %f",
location.latitude,location.longitude);
this concept use in directly in ur app delegte and check it ur latitude and long.
#pragma mark locationManager delegate
- (void)locationManager:(CLLocationManager *)manager didUpdateToLocation:(CLLocation *)newLocation fromLocation:(CLLocation *)oldLocation
{
//if the time interval returned from core location is more than two minutes we ignore it because it might be from an old session
if(abs([newLocation.timestamp timeIntervalSinceDate: [NSDate date]]) < 120)
{
//CLLocation *test = [[CLLocation alloc] initWithLatitude:-33.857034 longitude:151.035929];
currentLocation = newLocation;
coordinates = newLocation.coordinate;
latitude = currentLocation.coordinate.latitude;
longitude = currentLocation.coordinate.longitude;
[locationManager stopUpdatingLocation];
}
}
- (void)locationManager:(CLLocationManager *)manager didFailWithError:(NSError *)error
{
NSLog(#"%#", [error description]);
}
Location only shows on a real device. You may find the values in the CLLocationManager will work in the Simulator (possibly from your exchange - although it wont be very accurate) but the blue pin on the map will always be in CA!

Trying to get CLLocationCoordinate2D Latitude and Longitude

Hello im trying to get the latitude and longitude values where the the location of the user is
without having the map show up so basically it will run on the background. I guess i have to use the map kit but are there any examples?
If you don't want a map, you don't need MapKit. Just use CLLocationManager.
- (id) init {
if (self = [super init]) {
locationManager = [[CLLocationManager alloc] init];
[locationManager setDelegate:self];
[locationManager startUpdatingLocation];
}
return self;
}
- (void) locationManager:(CLLocationManager *)manager didUpdateToLocation:(CLLocation *)location fromLocation:(CLLocation *)oldLocation {
NSLog(#"lat:%f lon:%f", location.coordinate.latitude, location.coordinate.longitude);
}