[Qgis-developer] OGRSpatialReference problem in QGIS
Frank Warmerdam
warmerdam at pobox.com
Mon Aug 17 11:06:58 EDT 2009
Florian Hillen wrote:
> Hi list,
>
> I have a problem with OGR in Quantum GIS.
>
> For my Plugin which reprojects rasterdata to another CS, I need a WKT
> description of the new CS. With the QgsProjectionSelector I can select a
> CS and read out the epsg code or the proj4 string. But I fail by setting
> this to an OGRSpatialReference and export that to a WKT.
> If I transform a 4326 scene with my plugin to 31467 (german system), the
> gdal warp works correctly (the coordinates are right), but the information
> about the geocs looks like this:
>
> PROJCS["unnamed",PROJECTION["Transverse_Mercator"],
...
> else
> {
> oSRS.SetProjCS((projectSelector->selectedName()).toUtf8());
> oSRS.importFromProj4((projectSelector->selectedProj4String()).toUtf8());
> }
...
> Can anyone help me with that?
> Do I have to use the C-API for that? I already had problems with the C++
> API of GDAL in Quantum GIS. My first attempt with the C-API for OGR wasn't
> successful either, that's why I asked you for a hint.
Florian,
What did the Proj4String look like? The WKT is lacking any description of
the GEOGCS which suprises me. I'm not clear on where the proj.4 strings
in projectSelector->selectedProj4String() come from but if this string is
reasonable and has earth model information it should be reflected in the WKT.
If not, perhaps I can fix importFromProj4.
Best regards,
--
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I set the clouds in motion - turn up | Frank Warmerdam, warmerdam at pobox.com
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and watch the world go round - Rush | Geospatial Programmer for Rent
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