[gdal-dev] OGR Geometry methods

[Marius Jigmond]

After some more investigation that is likely NOT the issue. I have an
ExecuteSQL statement which selects a certain polygon based on an
attribute value. Unfortunately it seems to return the wrong feature. The
feature I query for is unique so a duplicate is out of the question.
Here's the code:

#!/usr/bin/python

from osgeo import ogr
import sys, math, time, os

aquifer = '/data/romania/judeteEPSG3844.shp'
aqDS = ogr.Open(aquifer)
sql = 'select * from judeteEPSG3844 where DENJUD = "CLUJ"'
aqLayer = aqDS.ExecuteSQL(sql)
feat = aqLayer.GetFeature(0)
print aqLayer.GetFeatureCount()
print feat.GetField('DENJUD')
aqDS.ReleaseResultSet(aqLayer)

The result:
marius at mobi:~/temp$ run_sql.py 
1
TELEORMAN
marius at mobi:~/temp$ 

This explains why none of my centroids were remotely close to the
polygon.

Is there something wrong with my query or should I file a bug?

-marius

On Mon, 2011-07-11 at 20:46 -0500, Marius Jigmond wrote:

> I suppose a piece of code speaks louder :):
> 
> xsect = False
> for i in range(gridLayer.GetFeatureCount()):
>   feat = gridLayer.GetFeature(i)
>   geom = feat.GetGeometryRef()
>   point = geom.Centroid()
>   for j in range(aqLayer.GetFeatureCount()):
>     aqfeat = aqLayer.GetFeature(j)
>     aqgeom = aqfeat.GetGeometryRef()
>     if point.Intersect(aqgeom):
>       xsect = True
>       print 'ibound = 1'
>       break
>   if xsect:
>     feat.SetField('IBOUND', 1)
>     gridLayer.SetFeature(feat)
>     xsect = False
> 
> -marius
> 
> On Mon, 2011-07-11 at 20:34 -0500, Marius Jigmond wrote:
> 
> > Hi everyone,
> > 
> > I am trying to test whether centroids of polygons lie/intersect
> > within another polygon. I have tried Intersect, Within, and Contains
> > but they always return false. Should these methods work for my
> > intended purpose or do I need to implement a point in polygon
> > function? Thanks.
> > 
> > -marius 
> > 
> > _______________________________________________
> > gdal-dev mailing list
> > gdal-dev at lists.osgeo.org
> > http://lists.osgeo.org/mailman/listinfo/gdal-dev
> 
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