Did you compile gdal yourself, or use a pre-built package. It is also possible GDAL_DATA environment variable isn’t set.
kss From: [email protected] [mailto:[email protected]] On Behalf Of [email protected] Sent: Tuesday, October 18, 2011 4:12 AM To: [email protected] Subject: RE: [gdal-dev] Confused about datum transformations I’m not sure the code will help too much, but here are the relevant code fragments. I’m using a hand crafted VB.net wrapper which explains some of the syntax Private WGS84SRS As New OGRSpatialReference ' Coordinate system in WGS84 Private MapSRS As OGRSpatialReference ' Coordinate system of map Private ctWGS84toMap As OGRCoordinateTransformation ' Coordinate transform from WGS84 to map With WGS84SRS GDALError = .SetProjCS("WGS84 Datum") Debug.Assert(GDALError = OGRError.OGRERR_NONE, GetLastErrorMsg()) GDALError = .SetWellKnownGeogCS("WGS84") ' Define WGS84 coordinate system Debug.Assert(GDALError = OGRError.OGRERR_NONE, GetLastErrorMsg()) End With With MapSRS GDALError = .SetProjCS("Map coordinate system") Debug.Assert(GDALError = OGRError.OGRERR_NONE, GetLastErrorMsg()) GDALError = .ImportFromEPSG(3577) Debug.Assert(GDALError = OGRError.OGRERR_NONE, GetLastErrorMsg()) End With ctWGS84toMap = GDAL.CreateCoordinateTransformation(WGS84SRS, MapSRS) ' Create a coordinate transformation - WGS84 to map Debug.Assert(ctWGS84toMap IsNot Nothing, GetLastErrorMsg()) Marc, Can you provide the code leading to the error? On Tue, Oct 18, 2011 at 1:21 PM, Marc Hillman <[email protected]<mailto:[email protected]>> wrote: I have a GIS database, and all data is stored in WGS84 datum. I have developed an application using GDAL, and I now need to translate my WGS84 coordinates to several different datums, depending what map is loaded. I seem to be going around in circles, and need a nudge in the right direction. I am defining an OGRSpatialReference for each datum (WGS84 and current map) and then attempting to create an OGRCoordinateTransformation for the transformation.. This last step fails with a PROJ.4 error (“No PROJ.4 translation for destination SRS, coordinate transformation initialization failed” My question is - Do I need PROJ.4 to do the translation? Can I not just use ImportFromWKT to define my OGRSpatialReference? If so, is there a nice canned list of all the WKT somewhere? I’m keen to avoid PROJ.4 if possible as I’m not sure I can build it. _______________________________________________ gdal-dev mailing list [email protected]<mailto:[email protected]> http://lists.osgeo.org/mailman/listinfo/gdal-dev -- Best regards, Chaitanya kumar CH. +91-9494447584 17.2416N 80.1426E No virus found in this message. Checked by AVG - www.avg.com<http://www.avg.com> Version: 2012.0.1831 / Virus Database: 2092/4558 - Release Date: 10/17/11
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