[Qgis-developer] Python QGis Geometry.transform

[Barry Rowlingson]

On Thu, Dec 3, 2009 at 1:06 PM, motta.luiz at gmail.com
<motta.luiz at gmail.com> wrote:
> Hi All,
>
> I need transform geometry of one feature to other reference system.
>
> The API of geometry show the method transform
> int QgsGeometry::transform(const QgsCoordinateTransform)
>
> But in the Python, this methdos not exist.
> Console Python QGis
>> from qgis import
>> core geom = core.QgsGeometry()
>> print dir(geom.transform)
> exceptions.AttributeError: 'QgsGeometry' object has no attribute 'transform'
>
> I tested with:
> Ubuntu 9.10, QGis 1.3.0-Mimas code revision "exported"
> Windows XP, QGis 1.3-Mimas code revision 11638
>
> Do someone use this method in Python ?
>

 I think you need to use QgsCoordinateTransform - here's a snippet
from the GeoCoding plugin that transforms a point 'point' from
whatever proj4string is to EPSG:4326 to 'pt'.

   t=QgsCoordinateReferenceSystem()
   t.createFromEpsg(4326)
   f=QgsCoordinateReferenceSystem()
   f.createFromProj4(proj4string)
   transformer = QgsCoordinateTransform(f,t)
   pt = transformer.transform(point)

Barry


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