topic Re: Project AgsPoint (spatial reference 4326 to spatial reference 102100) in ArcGIS Runtime SDK for iOS Questions

Project AgsPoint (spatial reference 4326 to spatial reference 102100)

KOLDODUARTE — Mon, 18 Oct 2010 15:52:36 GMT

Hi all

We need to project the x and y obtained from the ESRI_Places_World/GeocodeServer and show it as a graph into a base map with spatial reference 102100.

We tested with:

AGSPoint *pt = addressCandidate.location;
AGSMutablePoint *newPoint = [AGSMutablePoint pointWithX:pt.x y:pt.y spatialReference:self.mapView.spatialReference];

But this not works.

Do you have any idea?

BR,
Koldo

Re: Project AgsPoint (spatial reference 4326 to spatial reference 102100)

DiveshGoyal — Tue, 19 Oct 2010 15:21:42 GMT

You cannot just assign a different spatial reference to existing coordinate values. You need to actually project the coordinate values.

The Geocode Service can project the values for you. All you need to do is use locationsForAddress:returnFields: outSpatialReference: and specify the spatial reference in which you want the results.

Re: Project AgsPoint (spatial reference 4326 to spatial reference 102100)

KOLDODUARTE — Sun, 12 Dec 2021 02:18:58 GMT

Hi technobrat,

Now I running with this code:

[self.locator locationsForAddress:addresses returnFields:outFields outSpatialReference:self.mapView.spatialReference];

... but the X & Y value for the set Point are the same, the coordinates are not changed... any idea?

Best Regards & Thanks,
Koldo

Re: Project AgsPoint (spatial reference 4326 to spatial reference 102100)

KOLDODUARTE — Mon, 25 Oct 2010 10:52:39 GMT

Hi all,

With this code:

[self.locator locationsForAddress:addresses returnFields:outFields outSpatialReference:self.mapView.spatialReference];

The point puts on the center of the map, just in Africa. Any idea?

Thanks & Best Regards,
Koldo.

Re: Project AgsPoint (spatial reference 4326 to spatial reference 102100)

DiveshGoyal — Thu, 28 Oct 2010 15:39:37 GMT

Hmm, not sure why you're still having problems.

Can you print the point to the console and see if the x,y, and spatial ref values look okay. Use NSLog(@"Point: %@", point);

Re: Project AgsPoint (spatial reference 4326 to spatial reference 102100)

KOLDODUARTE — Sun, 31 Oct 2010 15:06:35 GMT

Hmm, not sure why you're still having problems.

Can you print the point to the console and see if the x,y, and spatial ref values look okay. Use NSLog(@"Point: %@", point);

Ok... the console prints this:

2010-10-31 17:05:26.223 iWatch[470:207] Point: AGSPoint: x = -1.785897, y = 43.031819, spatial reference: [AGSSpatialReference: wkid = 102100, wkt = null]

Re: Project AgsPoint (spatial reference 4326 to spatial reference 102100)

DiveshGoyal — Mon, 01 Nov 2010 15:03:01 GMT

Is it possible that your Geocode service is on an ArcGIS Server older than 9.3.1?

The 102100 spatial reference was introduced at 9.3.1. Older servers dont understand it.

Re: Project AgsPoint (spatial reference 4326 to spatial reference 102100)

KOLDODUARTE — Sun, 12 Dec 2021 02:19:00 GMT

Thanks for the response Technobrat.

However, we are using a 931 ESRI geocode server:
http://tasks.arcgisonline.com/ArcGIS/rest/services/Locators/ESRI_Places_World/GeocodeServer

Indeed, we are trying some other alternatives as reproject the coordinates with the geometry service task:
http://sampleserver1.arcgisonline.com/ArcGIS/rest/services/Geometry/GeometryServer/project

Here we are facing another issue. We are not able to get the projected points to WKID:102100 using the delegate method:

- (void)geometryServiceTask:(AGSGeometryServiceTask *)geometryServiceTask operation:(NSOperation *)op didReturnProjectedGeometries:(NSArray *)newGeometry

Doesn´t this method have the input spatial reference as a parameter?

Any help will be appreciate it.

Cheers!

Koldo

Re: Project AgsPoint (spatial reference 4326 to spatial reference 102100)

DiveshGoyal — Mon, 01 Nov 2010 21:09:13 GMT

Ok. I am stumped. I'm not sure why your 931 Geocode Service does not give you back the correctly projected results.

For using the Geometry Service, your input geometries must have a valid spatial reference. Without this info, the geometry service cannot truly project your geometries.

If you're still having problems, I can take a look at your code to see what might be going on.

Re: Project AgsPoint (spatial reference 4326 to spatial reference 102100)

AlbertoTelletxea — Wed, 03 Nov 2010 23:49:04 GMT

Ok. I am stumped. I'm not sure why your 931 Geocode Service does not give you back the correctly projected results.

For using the Geometry Service, your input geometries must have a valid spatial reference. Without this info, the geometry service cannot truly project your geometries.

If you're still having problems, I can take a look at your code to see what might be going on.

Hi Technobrat

I am following the thread of Koldo. He is my colleague. I have prepared a XCode Project with the ESRI Sample project "GeocodingDemo". But I cannot upload it. The zip file is just 1,5Mb. If you provide me a mail I can forward it to you.
However, I am going to explain briefly what I did in the code to reproduce the issue.

I have just changed the base map (tiled) layer of the project "GeocodingDemo" to the one we use in our project, http://services.arcgisonline.com/ArcGIS/rest/services/World_Imagery/MapServer
with spatial reference: 102100.

Then in the GeocodingDemoViewController.m I write the following line to request the locations to the geolocator service:

[self.locator locationsForAddress:addresses returnFields:outFields outSpatialReference:self.mapView.spatialReference];

The result of this is that the address points are located at (0,0) in the map. The method is not properly using the outSpatialReference parameter.

Please let us know if the description of the issue is clear enough. And again if you provide me a mail I can forward to you the XCode Project.

Thanks in advance and best regards.

Alberto

Re: Project AgsPoint (spatial reference 4326 to spatial reference 102100)

HarikantJammi — Thu, 04 Nov 2010 12:12:09 GMT

below formula converts 4326 latitude to 102100 latitude

+ (double)toWebMercatorY:(double)latitude
{
double rad = latitude * 0.0174532;
double fsin = sin(rad);

double y = 6378137 / 2.0 * log((1.0 + fsin) / (1.0 - fsin));

return y;
}

below formula converts 4326 longitude to 102100 longitude
+ (double)toWebMercatorX:(double)longitude
{
double x = longitude * 0.017453292519943 * 6378137;

return x;
}

See my attachment , it contains a utility mercator convertor . You can simply import the class in your project and call the above static methods on it
I have tried it with location manager and it works!!!
Regards,
Harikant Jammi

Re: Project AgsPoint (spatial reference 4326 to spatial reference 102100)

DiveshGoyal — Fri, 05 Nov 2010 01:36:53 GMT

Hi, Alberto,

I managed to reproduce the problem by modifying the GeocodingSample as you suggested.

Yes, the locations returned by the Geocode Service are still not correctly projected to 102100 even when using locationsForAddress:returnFields: outSpatialReference:. The reason is that the ability to specify an outSpatialReference was only added at 10 in the REST API. The service that you are hitting is still only 931 and it is ignoring your request to reproject the location.

I must also admit, we should have mentioned in the API ref doc that this functionality is only available with 10 servers. We will fix the omission.

In the meanwhile, you can use a different GeocodeService from a 10 server that provides this functionality, but if you want to continue using this particular service, you will have to reproject the point using other means.

Now, before you try to reproject the point, you must FIRST manually assign a spatial reference to the returned locations. This is because the service does not have a valid spatial reference (you can tell by looking at the services directory page) and consequently, the returned location dont have a spatial reference either. I think it is safe to assume that the returned locations are in WGS 84. So you must manually assign the result AGSPoint a spatial reference with WKID=4326. This is crucial because most geometry operations require your input geometries to have a spatial reference.

The SDK contains a global function called AGSGeometryWebMercatorToGeographic() that can help you convert from WGS84 to WebMercator if you don't want to use a Geometry Service.

Hope this helps.

Re: Project AgsPoint (spatial reference 4326 to spatial reference 102100)

PaulJereb — Sun, 12 Dec 2021 02:19:03 GMT

Hi technobrat,

I'm facing the same problem (my adressCandidate returns with spatialReference = Null) when using the Locator from http://tasks.arcgisonline.com/ArcGIS/rest/services/Locators/TA_Address_EU/GeocodeServer

I'd need to project it to WKID 31259... Any tip?

AGSSpatialReference* outSR = [AGSSpatialReference spatialReferenceWithWKID:31259  WKT:nil];
 
[self.locator locationsForAddress:addresses returnFields:outFields outSpatialReference:outSR];

The log-output for the returned candidate:

Candidate : AGSPoint: x = 15.441723, y = 47.067916, spatial reference: [(null)]

BR, Paul

Re: Project AgsPoint (spatial reference 4326 to spatial reference 102100)

DiveshGoyal — Fri, 05 Nov 2010 15:28:59 GMT

Paul,

You too will need to manually project the returned location (don't forget to assign it a spatial reference first though). The SDK doesn't have any convenient functions to convert to 31259. You'll have to use the AGSGeometryServiceTask.

Re: Project AgsPoint (spatial reference 4326 to spatial reference 102100)

PaulJereb — Sun, 07 Nov 2010 10:34:09 GMT

Divesh,

thanks for your reply. I tried to use the AGSGeometryServiceTask to project the point based on the GeometryServiceSample.

[self.gst projectGeometries:self.geometryArray:outSR];

When building I get the following warning:
'AGSGeometryServiceTask' may not respond to '-projectGeometries::'

which makes the application crash with the following output:
-[AGSGeometryServiceTask projectGeometries::]: unrecognized selector sent to instance 0x727a140
*** Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '-[AGSGeometryServiceTask projectGeometries::]: unrecognized selector sent to instance 0x727a140'

After checking the AGSGeometryServiceTask.h I found that "projectGeometries" is actually missing:
AGSGeometryServiceTask.h

Can you tell what I'm doing wrong?

BR, Paul

Re: Project AgsPoint (spatial reference 4326 to spatial reference 102100)

DiveshGoyal — Tue, 09 Nov 2010 16:02:47 GMT

You're missing an argument name in the method. It should be -

[self.gst projectGeometries:self.geometryArray toSpatialReference:outSR];

Re: Project AgsPoint (spatial reference 4326 to spatial reference 102100)

PaulJereb — Sun, 12 Dec 2021 02:19:06 GMT

thanks a lot! the projectGeometries call seems to work now (the simulator connects to sampleserver3) but after that the following methods are not called.

- (void)geometryServiceTask:(AGSGeometryServiceTask *)geometryServiceTask operation:(NSOperation *)op didReturnProjectedGeometries:(NSArray *)projectedGeometries
{
 NSLog(@"didReturnProjectedGeometries");
}

- (void)geometryServiceTask:(AGSGeometryServiceTask *)geometryServiceTask operation:(NSOperation*)op didFailProjectWithError:(NSError *)error {
 NSLog(@"didFailProjectWithError");
}

Is there again something I forgot? I used the GeometryServiceSample as a basis and triple checked already if something's missing...

BR, Paul

Re: Project AgsPoint (spatial reference 4326 to spatial reference 102100)

KOLDODUARTE — Thu, 11 Nov 2010 17:27:19 GMT

below formula converts 4326 latitude to 102100 latitude

+ (double)toWebMercatorY:(double)latitude
{
double rad = latitude * 0.0174532;
double fsin = sin(rad);

double y = 6378137 / 2.0 * log((1.0 + fsin) / (1.0 - fsin));

return y;
}

below formula converts 4326 longitude to 102100 longitude
+ (double)toWebMercatorX:(double)longitude
{
double x = longitude * 0.017453292519943 * 6378137;

return x;
}

See my attachment , it contains a utility mercator convertor . You can simply import the class in your project and call the above static methods on it
I have tried it with location manager and it works!!!
Regards,
Harikant Jammi

Hi all & thanks all to, especially Harikant Jammi,

With your solutions, now It works fine, good job Jammi!

BR,
Koldo.

Re: Project AgsPoint (spatial reference 4326 to spatial reference 102100)

HarikantJammi — Mon, 15 Nov 2010 14:29:22 GMT

welcome koldo!!

glad to know that my code helped you.

Regards,
Harikant Jammi

Re: Project AgsPoint (spatial reference 4326 to spatial reference 102100)

LucaAlferi1 — Sun, 12 Dec 2021 02:19:08 GMT

below formula converts 4326 latitude to 102100 latitude

+ (double)toWebMercatorY:(double)latitude
{
double rad = latitude * 0.0174532;
double fsin = sin(rad);

double y = 6378137 / 2.0 * log((1.0 + fsin) / (1.0 - fsin));

return y;
}

below formula converts 4326 longitude to 102100 longitude
+ (double)toWebMercatorX:(double)longitude
{
double x = longitude * 0.017453292519943 * 6378137;

return x;
}

See my attachment , it contains a utility mercator convertor . You can simply import the class in your project and call the above static methods on it
I have tried it with location manager and it works!!!
Regards,
Harikant Jammi

Hi Jammi.
I'm a beginner of objective-C. How can use your fantastic code in my code:

- (void)locator:(AGSLocator *)locator operation:(NSOperation *)op didFindLocationsForAddress:(NSArray *)candidates{
    
    //check and see if we didn't get any results
 if (candidates == nil || [candidates count] == 0){
        //show alert if we didn't get results
        UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"Informazione" message:@"Nessun risultato trovato" delegate:nil cancelButtonTitle:@"OK" otherButtonTitles:nil];
        [alert show];
        [alert release];
 }
 else {
        //use these to calculate extent of results
        double xmin = DBL_MAX;
        double ymin = DBL_MAX;
        double xmax = -DBL_MAX;
        double ymax = -DBL_MAX;
  
  //create the callout template, used when the user displays the callout
  self.calloutTemplate = [[[AGSCalloutTemplate alloc]init] autorelease];
        
        //loop through all candidates/results and add to graphics layer
  for (int i=0; i<[candidates count]; i++){            
   AGSAddressCandidate *addressCandidate = (AGSAddressCandidate *)[candidates objectAtIndex:i];
            
            //get the location from the candidate
            AGSPoint *pt = addressCandidate.location;
            
            //accumulate the min/max
            if (pt.x  < xmin)
                xmin = pt.x;
            
            if (pt.x > xmax)
                xmax = pt.x;
            
            if (pt.y < ymin)
                ymin = pt.y;
            
            if (pt.y > ymax)
                ymax = pt.y;
          
 //create a marker symbol to use in our graphic
            AGSPictureMarkerSymbol *marker = [AGSPictureMarkerSymbol pictureMarkerSymbolWithImageNamed:@"BluePushpin.png"];
            marker.xoffset = 9;
            marker.yoffset = -16;
            marker.hotspot = CGPointMake(-9, -11);
            //set the text and detail text based on 'Name' and 'Descr' fields in the attributes
            self.calloutTemplate.titleTemplate = self.searchBar.text;
            //create the graphic
    AGSGraphic *graphic = [[AGSGraphic alloc] initWithGeometry: pt symbol:marker attributes:[[addressCandidate.attributes mutableCopy] autorelease] infoTemplateDelegate:self.calloutTemplate];
            
            
            //add the graphic to the graphics layer
            
   [self.graphicsLayer addGraphic:graphic];
            
            if ([candidates count] == 1)
            {
                //we have one result, center at that point
                [self.mapView5 centerAtPoint:pt animated:NO];
                
    // set the width of the callout
    self.mapView5.callout.width = 250;
                
                //show the callout
                [self.mapView5 showCalloutAtPoint:(AGSPoint *)graphic.geometry forGraphic:graphic animated:YES];
            }
   
   //release the graphic bb  
   [graphic release];            
  }
        
        //if we have more than one result, zoom to the extent of all results
        int nCount = [candidates count];
        if (nCount > 1)
        {            
            AGSMutableEnvelope *extent = [AGSMutableEnvelope envelopeWithXmin:xmin ymin:ymin xmax:xmax ymax:ymax spatialReference:self.mapView5.spatialReference];
            [extent expandByFactor:1.5];
   [self.mapView5 zoomToEnvelope:extent animated:YES];
        }
 }
    
    //since we've added graphics, make sure to redraw
    [self.graphicsLayer dataChanged];
    
}

Thanks