Hi Thomas, > >PS : Is there any documentation explaining more in detail than the javadoc >the use of different MathTransforms ?... >
If you mean code examples etc.. then you can take a look in unit tests of MathTransformaBuilder. http://svn.geotools.org/geotools/trunk/gt/modules/library/referencing/src/test/java/org/geotools/referencing/operation/builder/MathTransformBuilderTest.java there is no other documentation than javadoc about what you want yet (my bad). If you mean the theory of LSM and 2D transformations (Similar, Affine, Projective) then there are many resources on the internet (wikipedia), but actually I don't know about documentation focused just on this topic a describing it all together. I'm just working on command line utility for generating worldfile from set of GCPs with control of used transformation method and errors statistics.I'll have to write some documentation about that as well (but maybe just in Czech language). I'll inform about that when I'll finish it. Bests, Jan. >2008/5/6 Anaxa Gore <[EMAIL PROTECTED]>: > >> Hi, >> >> I want to write some georeferenced informations into a GridCoverage2D. To >> do this, I create a Writable Raster, like this : >> >> final int width = 5000; >> final int height = 5000; >> WritableRaster raster = >> RasterFactory.createBandedRaster(DataBuffer.TYPE_FLOAT,width, height, 1, >> null); >> >> I perform some calculation on my datas and then want to write some points >> into the raster, just created. So I suppose I need a MathTransform, from my >> Envelope2D, describing my geograhic area, to my raster coordinates...? >> I am doing something like this : >> >> DirectPosition2D leftdown = new DirectPosition2D(102.0,23.0); >> DirectPosition2D rightup = new DirectPosition2D(103.0,24.0); >> DirectPosition2D inter = new DirectPosition2D(102.5,23.5); >> Envelope2D env = new Envelope2D(leftdown, rightup); >> >> List<MappedPosition> list = new ArrayList<MappedPosition>(2); >> >> MappedPosition mp1 = new MappedPosition(new DirectPosition2D(0,0), >> leftdown); >> MappedPosition mp2 = new MappedPosition(new >> DirectPosition2D(width,height),rightup); >> MappedPosition mp3 = new MappedPosition(new >> DirectPosition2D(width/2,height/2), inter); >> >> list.add(mp1); >> list.add(mp2); >> list.add(mp3); >> >> AffineTransformBuilder mtb = new AffineTransformBuilder(list); >> MathTransform mt = null; >> >> try { >> mt = mtb.getMathTransform(); >> } catch (FactoryException ex) { >> Logger.getLogger(_2_WriteRaster.class.getName()).log(Level.SEVERE, >> null, ex); >> } >> >> But I always get this error, when trying to get the MathTransform : >> >> Exception in thread "main" javax.vecmath.SingularMatrixException: cannot >> invert matrix >> at javax.vecmath.GMatrix.invertGeneral(GMatrix.java:1711) >> at javax.vecmath.GMatrix.invert(GMatrix.java:397) >> at >> org.geotools.referencing.operation.builder.ProjectiveTransformBuilder.calculateLSM(ProjectiveTransformBuilder.java:243) >> at >> org.geotools.referencing.operation.builder.AffineTransformBuilder.getProjectiveMatrix(AffineTransformBuilder.java:99) >> at >> org.geotools.referencing.operation.builder.ProjectiveTransformBuilder.computeMathTransform(ProjectiveTransformBuilder.java:280) >> at >> org.geotools.referencing.operation.builder.MathTransformBuilder.getMathTransform(MathTransformBuilder.java:687) >> at >> org.geotools.referencing.operation.builder.MathTransformBuilder.getErrorStatistics(MathTransformBuilder.java:645) >> at >> org.geotools.referencing.operation.builder.MathTransformBuilder.getTransformation(MathTransformBuilder.java:733) >> at >> geotools_tests.rasters._2_WriteRaster.main(_2_WriteRaster.java:117) >> >> Is there something wrong in my code ? >> Thomas >> > >------------------------------------------------------------------------- >This SF.net email is sponsored by the 2008 JavaOne(SM) Conference >Don't miss this year's exciting event. There's still time to save $100. >Use priority code J8TL2D2. >http://ad.doubleclick.net/clk;198757673;13503038;p?http://java.sun.com/javaone >_______________________________________________ >Geotools-gt2-users mailing list >[email protected] >https://lists.sourceforge.net/lists/listinfo/geotools-gt2-users > > ------------------------------------------------------------------------- This SF.net email is sponsored by the 2008 JavaOne(SM) Conference Don't miss this year's exciting event. There's still time to save $100. Use priority code J8TL2D2. http://ad.doubleclick.net/clk;198757673;13503038;p?http://java.sun.com/javaone _______________________________________________ Geotools-gt2-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/geotools-gt2-users
