[Qgis-developer] QGis AutoGCP Plugin

[Carson Farmer]

I think this is probably what you're looking for:

crs = QgsCoordinateReferenceSystem ()
crs.createFromProj4(theProj4Str)
print crs.toWkt()

no need to use additional libraries or anything!

On 29 September 2010 17:18, Benoit de Cabissole <benoit at exigesa.com> wrote:
> Hi Francois,
>
> If you are in Python, you could use GDAL with something like the following:
>
> import osr
> ...
> theProj4Str = "+proj=utm +zone=36 +south +a=6378249.144808011
> +b=6356514.966204134 +units=m +no_defs"
> outSr = osr.SpatialReference()
> outSr.ImportFromProj4(theProj4Str)
> outWkt = outSr.ExportToWkt()
>
> and use outWkt as the 'dst_wtk' parameter for raster creation.
>
> HTH,
> Benoit
>
>
>
>  -----Original Message-----
> From: qgis-developer-bounces at lists.osgeo.org
> [mailto:qgis-developer-bounces at lists.osgeo.org]On Behalf Of Francois Maass
> Sent: Wednesday, 29 September 2010 17:33
> To: qgis-developer at lists.osgeo.org
> Subject: [Qgis-developer] QGis AutoGCP Plugin
>
> Hello everyone!
>
>
>
> I’ve been struggling with this for quite some time now, but I can’t seem to
> find the proper solution.  We need to set the projection definition to
> provided datasets, and have, up to now, been doing it by using our own
> projection dialog. We now want to change our plugin to use the, already
> implemented, QGIS projection dialog.
>
> So my question is as follows:
>
> Is there a way to convert a projection definition such as those returned by
> the QGIS projection dialog
> eg:
>    +proj=utm +zone=36 +south +a=6378249.144808011 +b=6356514.966204134
> +units=m +no_defs
>
> to the extended form such as the following:
>
>    PROJCS["UTM Zone 36, Southern Hemisphere",GEOGCS["Unknown datum based
> upon the Clarke 1880 ellipsoid",DATUM["Not specified (based on Clarke 1880
> spheroid)",SPHEROID["Clarke
> 1880",6378249.144808011,293.4663076556303,AUTHORITY["EPSG","7034"]]],PRIMEM["Greenwich",0],UNIT["degree",0.0174532925199433]],PROJECTION["Transverse_Mercator"],PARAMETER["latitude_of_origin",0],PARAMETER["central_meridian",33],PARAMETER["scale_factor",0.9996],PARAMETER["false_easting",500000],PARAMETER["false_northing",10000000],UNIT["Meter",1]]
>
>
>
> The reason for this is that the GDAL functions for setting the projection
> definition, only accepts the extended form.  If this is already implemented
> in a QGIS or other class that you know of, I would greatly appreciate it.
> (I don’t think I am qualified enough to attempt doing it myself. J )
>
> Thank you for your time and efforts!
> Francois Maass
> Foxhat Solutions
>
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>



-- 
Carson J. Q. Farmer
ISSP Doctoral Fellow
National Centre for Geocomputation
National University of Ireland, Maynooth,
http://www.carsonfarmer.com/