[Proj] Coordinate transformation assistance

[Tamas Szekeres]

Bjørn,

Did you try using ImportFromProj4 with more success?
You should also test with a file monitoring tool (like SysInternals
filemon) to see the expected location of the epsg file.

Best regards,

Tamas


2007/4/13, Bjørn Krangnes <bkr at devonor.com>:
> Frank,
> The expected result is Easting:200049.410 Northing: 199965.743 (sorry,
> typo error in my previous answer)
> I forgot to mention that I still get returncode 6 from ImportFromEPSG.
> Also adding the EPSG file for both ITM and IG.
> # IRENET95 / Irish Transverse Mercator
> <2157> +proj=tmerc +lat_0=53.5 +lon_0=-8 +k=0.999820 +x_0=600000
> +y_0=750000 +ellps=GRS80 +towgs84=0,0,0,0,0,0,0 +units=m +no_defs  <>
> # TM75 / Irish Grid
> <29903> +proj=tmerc +lat_0=53.5 +lon_0=-8 +k=1.000035 +x_0=200000
> +y_0=250000 +a=6377340.189 +b=6356034.447938534 +units=m +no_defs  <>
>
> Regards
> Bjørn
>
> > Bjørn Krangnes wrote:
> >> Hi,
> >>
> >> I am trying to go from Irish Transverse Mercator to IrishGrid75 Ireland
> >> using GDAL C# and EPSG codes.
> >>
> >> The code is like this:
> >>
> >>
> >>             double[] xyz = new double[3];
> >>
> >>             OGR.SpatialReference inp = new OGR.SpatialReference(null);
> >>             OGR.SpatialReference outp = new OGR.SpatialReference(null);
> >>
> >>
> >>             int stat1 = inp.ImportFromEPSG(2157);   // Irish Transverse
> >> Mercator
> >>             int stat2 = outp.ImportFromEPSG(29903); // IrishGrid75
> >> Ireland
> >>
> >>             OGR.CoordinateTransformation tra = new
> >> OGR.CoordinateTransformation(inp, outp);
> >>
> >>             xyz[0] = 600000.0;
> >>             xyz[1] = 700000.0;
> >>             xyz[2] = 22.22;
> >>
> >>             tra.TransformPoint(xyz);
> >>
> >> I think the problems is with ImportFromEPSG because both istat1 and
> >> istat2
> >> is 6 after execution. How to initialize the EPSG codes ?
> >>
> >> I am resending this request beacuse I have not had any feedback on my
> >> previous request.
> >
> > Bjørn,
> >
> > You don't indicate what the transformed result is or why you think there
> > is an error.  But if ImportFromEPSG() is failing (result 6 is
> > OGRERR_FAILURE) then it is likely because the EPSG .csv files aren't
> > being found.  One way around this is to set the GDAL_DATA environment
> > variable to point to the directory where the files like pcs.csv and
> > gcs.csv
> > live.  In the source distribution they are in the gdal\data directory.
> >
> > I think you can also do something like:
> >
> >    Gdal.PushFinderLocation("C:\\gdal\\data");
> >
> > or
> >
> >    Gdal.SetConfigOption( "GDAL_DATA", "C:\\gdal\\data" );
> >
> > though my csharp-gdal-fu is weak.
> >
> > Best regards,
> > --
> > ---------------------------------------+--------------------------------------
> > I set the clouds in motion - turn up   | Frank Warmerdam,
> > warmerdam at pobox.com
> > light and sound - activate the windows | http://pobox.com/~warmerdam
> > and watch the world go round - Rush    | President OSGeo, http://osgeo.org
> >
> > _______________________________________________
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> >
>
>
> Bjørn Krangnes
> Devonor AS
> Telephone: +47 32 29 96 90
> Direct Line: +47 32 29 96 91
> Mobile: +47 45035640
> E-mail: bkr at devonor.com
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>
>
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