Hi again,
After digging deeper, it seems the different transformation results I
observe with 21.2 are caused by differing CRS-definitions.
When exporting the CRSs from 14.3 to WTK and loading those WTKs with
21.2, I get the same (valid?) transformation result I get with 14.3.
However the difference between 21.2 WTKs and 14.3 WTKs seem to be
limited to rounding errors:
WTK 14.3:
PROJCS["MGI (Ferro) / Austria GK West Zone",
GEOGCS["MGI (Ferro)",
DATUM["Militar-Geographische Institut (Ferro)",
SPHEROID["Bessel 1841", 6377397.155, 299.1528128,
AUTHORITY["EPSG","7004"]],
AUTHORITY["EPSG","6805"]],
PRIMEM["Ferro", -17.666666666666668, AUTHORITY["EPSG","8909"]],
UNIT["degree", 0.017453292519943295],
AXIS["Geodetic longitude", EAST],
AXIS["Geodetic latitude", NORTH],
AUTHORITY["EPSG","4805"]],
PROJECTION["Transverse_Mercator"],
PARAMETER["central_meridian", 28.0],
PARAMETER["latitude_of_origin", 0.0],
PARAMETER["scale_factor", 1.0],
PARAMETER["false_easting", 0.0],
PARAMETER["false_northing", -5000000.0],
UNIT["m", 1.0],
AXIS["Easting", EAST],
AXIS["Northing", NORTH],
AUTHORITY["EPSG","31251"]]
PROJCS["MGI / Austria Lambert",
GEOGCS["MGI",
DATUM["Militar-Geographische Institut",
SPHEROID["Bessel 1841", 6377397.155, 299.1528128,
AUTHORITY["EPSG","7004"]],
TOWGS84[601.705, 84.263, 485.227, 4.7354, -1.3145, -5.393, -2.3887],
AUTHORITY["EPSG","6312"]],
PRIMEM["Greenwich", 0.0, AUTHORITY["EPSG","8901"]],
UNIT["degree", 0.017453292519943295],
AXIS["Geodetic longitude", EAST],
AXIS["Geodetic latitude", NORTH],
AUTHORITY["EPSG","4312"]],
PROJECTION["Lambert_Conformal_Conic_2SP"],
PARAMETER["central_meridian", 13.333333333333334],
PARAMETER["latitude_of_origin", 47.5],
PARAMETER["standard_parallel_1", 49.0],
PARAMETER["false_easting", 400000.0],
PARAMETER["false_northing", 400000.0],
PARAMETER["scale_factor", 1.0],
PARAMETER["standard_parallel_2", 46.0],
UNIT["m", 1.0],
AXIS["Easting", EAST],
AXIS["Northing", NORTH],
AUTHORITY["EPSG","31287"]]
WTK 21.2:
PROJCS["MGI (Ferro) / Austria GK West Zone",
GEOGCS["MGI (Ferro)",
DATUM["Militar-Geographische Institut (Ferro)",
SPHEROID["Bessel 1841", 6377397.155, 299.1528128,
AUTHORITY["EPSG","7004"]],
AUTHORITY["EPSG","6805"]],
PRIMEM["Ferro", -17.666666666666668, AUTHORITY["EPSG","8909"]],
UNIT["degree", 0.017453292519943295],
AXIS["Geodetic latitude", NORTH],
AXIS["Geodetic longitude", EAST],
AUTHORITY["EPSG","4805"]],
PROJECTION["Transverse_Mercator", AUTHORITY["EPSG","9807"]],
PARAMETER["central_meridian", 28.0],
PARAMETER["latitude_of_origin", 0.0],
PARAMETER["scale_factor", 1.0],
PARAMETER["false_easting", 0.0],
PARAMETER["false_northing", -5000000.0],
UNIT["m", 1.0],
AXIS["Northing", NORTH],
AXIS["Easting", EAST],
AUTHORITY["EPSG","31251"]]
PROJCS["MGI / Austria Lambert",
GEOGCS["MGI",
DATUM["Militar-Geographische Institut",
SPHEROID["Bessel 1841", 6377397.155, 299.1528128,
AUTHORITY["EPSG","7004"]],
TOWGS84[601.705, 84.263, 485.227, 4.7354, -1.3145, -5.393, -2.3887],
AUTHORITY["EPSG","6312"]],
PRIMEM["Greenwich", 0.0, AUTHORITY["EPSG","8901"]],
UNIT["degree", 0.017453292519943295],
AXIS["Geodetic latitude", NORTH],
AXIS["Geodetic longitude", EAST],
AUTHORITY["EPSG","4312"]],
PROJECTION["Lambert_Conformal_Conic_2SP", AUTHORITY["EPSG","9802"]],
PARAMETER["central_meridian", 13.333333333333336],
PARAMETER["latitude_of_origin", 47.5],
PARAMETER["standard_parallel_1", 48.99999999999999],
PARAMETER["false_easting", 400000.0],
PARAMETER["false_northing", 400000.0],
PARAMETER["scale_factor", 1.0],
PARAMETER["standard_parallel_2", 46.0],
UNIT["m", 1.0],
AXIS["Northing", NORTH],
AXIS["Easting", EAST],
AUTHORITY["EPSG","31287"]]
Am Fr., 20. Sept. 2019 um 10:23 Uhr schrieb Clemens Eisserer
<linuxhi...@gmail.com>:
>
> Hi,
>
> After upgrading an application from geotools-14.3 to 21.2 I've
> observed strange behaviour when transforming points from one CRS
> (EPSG:31251) to another (EPSG:31287).
> The original code we had dies with an exception, however even two
> other tries return different results from what I got with 14.3.
> With an external tool I also get results which are identical to what
> 14.3 returns.
>
> With 14.3 all 3 tries succeed and return the expected result:
> > OldWay: POINT (259878.57433310486 377178.60575377225)
> > Plain: GeneralDirectPosition[259878.57433310486, 377178.60575377225]
> > JTS: POINT (259878.57433310486 377178.60575377225)
>
> With 21.2 the geometryBuilder-based way fails, the two others return
> consistent but different (wrong?) results:
> > Plain: GeneralDirectPosition[219916.12907210115, 405574.2553041743]
> > JTS: POINT (219916.12907210115 405574.2553041743)
> > java.lang.IllegalArgumentException: DirectPosition cannot have a null CRS
> > at
> > org.geotools.geometry.jts.spatialschema.geometry.DirectPositionImpl.setCRS(DirectPositionImpl.java:155)
> > at
> > org.geotools.geometry.jts.spatialschema.geometry.DirectPositionImpl.<init>(DirectPositionImpl.java:125)
> > at
> > org.geotools.geometry.jts.spatialschema.geometry.primitive.PrimitiveFactoryImpl.createDirectPosition(PrimitiveFactoryImpl.java:95)
> > at
> > org.geotools.geometry.jts.spatialschema.geometry.primitive.PrimitiveFactoryImpl.createPoint(PrimitiveFactoryImpl.java:103)
> > at
> > org.geotools.geometry.GeometryBuilder.createPoint(GeometryBuilder.java:352)
> > at
> > org.geotools.geometry.GeometryBuilder.createPoint(GeometryBuilder.java:320)
>
> Any idea whats going on here?
>
> Best regards, Clemens
>
>
> public class CoordinateTransformTest {
>
> @Test
> public void testTransform() throws FactoryException, TransformException {
> CoordinateReferenceSystem gkCRS = CRS.decode("EPSG:31251");
> CoordinateReferenceSystem dbCRS = CRS.decode("EPSG:31287");
>
> MathTransform transform = CRS.findMathTransform(gkCRS, dbCRS, true);
> DirectPosition2D pos2D = new DirectPosition2D(86765.44, 238436.25);
>
> DirectPosition posTransformed = transform.transform(pos2D, null);
> System.out.println("Plain: "+posTransformed);
>
> Point transformedPoint = (Point)
> JTS.transform(JTS.toGeometry(pos2D.getDirectPosition()), transform);
> System.out.println("JTS: "+transformedPoint);
> }
>
> @Test
> public void testOldWay() throws FactoryException, TransformException {
> CoordinateReferenceSystem gkCRS = CRS.decode("EPSG:31251");
> CoordinateReferenceSystem dbCRS = CRS.decode("EPSG:31287");
>
> GeometryBuilder geometryBuilder = new GeometryBuilder(gkCRS);
>
> org.opengis.geometry.primitive.Point point =
> geometryBuilder.createPoint(86765.44, 238436.25);
>
> MathTransform mtf = CRS.findMathTransform(gkCRS, dbCRS, true);
>
> Point transformedPoint = (Point)
> JTS.transform(JTS.toGeometry(point.getDirectPosition()), mtf);
> System.out.println("OldWay: "+transformedPoint);
> }
> }
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