ARCIMS Emulator getProjection with ArcGIS9.0
Howard Butler
hobu at IASTATE.EDU
Sun Sep 26 21:02:17 PDT 2004
I have a Python solution that utilizes OGR and Python mapscript to emulate
ArcIMS 9.0. It works correctly with ESRI WKT by transforming it to a proj4
string using OGR. Contact my off list if you are interested in a copy
At 09:36 PM 9/26/2004, Frank Warmerdam wrote:
>Ellis Robin (Bundaberg) wrote:
> > <FEATURECOORDSYS
> >
> string="GEOGCS["GCS_GDA_1994",DATUM["D_GDA_1994",SPHEROID...
>
> >
> > The com.esri.esrimap.Esrimap file looked as though it would cater for
> this difference in XML, however I've found that
> > the process falls over at this stage:
> >
> > my $l = new mapscript::layerObj($map);
> $l->setWKTProjection($filtcs_wkt); $envelope->project(new
> > mapscript::projectionObj($l->getProjection()),new
> mapscript::projectionObj($map->getProjection()));
>
>Robin,
>
>Unfortunately the OGC WKT coordinate system specification was pretty
>weak and there are a variety of variations. I presume that the
>layerObj->setWKTProjection() method is expecting something that is
>compatible with the OGR WKT definition. However, ESRI WKT is somewhat
>different. The key (deep down in OGR) is to import ESRI WKT and
>then to call morphFromESRI() on the WKT to "normalize" the definition.
>
>As far as I know this is not directly accessable from MapScript, but I
>would suggest layerObj->setWKTProjection() be altered to do this morphing
>internally if the WKT is prefixed with something like ESRI:::. Then the
>above mapscript could apply that. In fact, we might want to change the
>setWKTProjection() method to use the OGRSpatialReference::SetFromUserInput()
>method which includes escapes for various formats, including ESRI morphing.
>
>Of course, I could be a bit off target on what the real issue is. I wouldn't
>have expected any serious issues in a simple GEOGCS definition.
>
>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 | Geospatial Programmer for Rent
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