[Geotools-gt2-users] Coordinate Transformation EPSG:4326 to EPSG:23031

[Wladimir S. <bo...@gm...>]

Hi,

 I have a GPX file. I use GEOTOOLS to transform the wpt form EPSG:4326
to ESPG:23031. My problem is not getting the desired results.

For example: For the point <wpt lat="41.5549967" lon="1.6694312"> the result
must be X:389132.033 Y:4601425.53. but i obtain this result X:389036.16739
Y:4601396.25356. Where is the problem ???

There is my code.

import org.opengis.referencing.FactoryException;
import org.opengis.referencing.crs.*;
import org.opengis.referencing.operation.*;
import org.opengis.spatialschema.geometry.DirectPosition;
import org.opengis.spatialschema.geometry.MismatchedDimensionException;
import org.geotools.geometry.GeneralDirectPosition;
import org.geotools.referencing.CRS;
import org.geotools.referencing.FactoryFinder;
public class TransCoord {
 TransCoord(){
  try {
   //getTranformEPSG("234","23031","4326",389132.033,4601425.53);
   getTranformEPSG("234","4326","23031",1.6694312,41.5549967);
  } catch (MismatchedDimensionException e) {
   e.printStackTrace();
  } catch (FactoryException e) {
   e.printStackTrace();
  } catch (TransformException e) {
   e.printStackTrace();
  }
 }

 public double[] getTranformEPSG(java.lang.String key,String inEpsg,String
outEpsg,double coordX,double coordY) throws FactoryException,
MismatchedDimensionException, TransformException{
  double[]punt=new double[2];
  double[]puntOut=new double[2];
  String inEpsgStr="";
  String outEpsgStr="";

  //Se puede enviar el codigo EPSG con o sin EPSG:
  if(inEpsg.indexOf("EPSG")!=-1){inEpsgStr=inEpsg;}else{inEpsgStr="EPSG:"+inEpsg;}
  if(outEpsg.indexOf("EPSG")!=-1){outEpsgStr=outEpsg;}else{outEpsgStr="EPSG:"+outEpsg;}

  //Geotools 2.3 con el True devuelve la X primero
  CoordinateReferenceSystem sourceCRS = CRS.decode(inEpsgStr,true);
  CoordinateReferenceSystem targetCRS = null;

  targetCRS = CRS.decode(outEpsgStr,true);

  //System.out.println("---------------------");
  //System.out.println("Sistema:"+"("+outEpsgStr+")"+targetCRS.toWKT().toString());
  //System.out.println("---------------------");

  //Geotools 2.3 con el True no da error de Datum Bursa Wolf
  //MathTransform mathTransform =CRS.findMathTransform( sourceCRS,
targetCRS,true );
  MathTransform mathTransform =CRS.findMathTransform(sourceCRS, targetCRS,
true);
  DirectPosition pt = new GeneralDirectPosition(coordX, coordY); //x,y,z
     pt = mathTransform.transform(pt, null);
     punt = pt.getCoordinates();
     puntOut[0]=Math.floor(punt[0]*100000)/100000;
  puntOut[1]=Math.floor(punt[1]*100000)/100000;
     //puntOut[0]=punt[0];
  //puntOut[1]=punt[1];
     System.out.println("X:"+puntOut[0]+" Y:" + puntOut[1]);
//longitude,latitude
  return puntOut;
 }

 public static void main(String[] args) {
  new TransCoord();
 }
}