Tai, GDAL needs GEOS to perform these geometry functions. Make sure you install that.
On Sat, Jul 21, 2012 at 12:19 PM, taibc <taibc_colt...@yahoo.com> wrote: > Hi Chaitanya, > > I still can't run the method "Geometry::Within". And I got the error: "GEOS > support not enable" when trying use this method. > > Please find the attached file for sample code. > http://osgeo-org.1560.n6.nabble.com/file/n4989766/Source1.cpp Source1.cpp > > About spatial filter, you said that: we can use the spatial filter of the > ogr layer to filter the point features. But, I think it is used to filter > features that geometrically intersect the filter geometry. > > For example: if I have one polygon A feature, I can use the method > "SetSpatialFilter" to get other features (Point or Polygon) that > geometrically *intersect* with A. > > > > chaitanya_ch wrote > > > > Tai, > > > > You can use the spatial filter of the ogr layer to filter the point > > features to speed things up. You will still have to test if the point is > > within the polygon but it will be faster. > > > > Also, make sure the test is like point->Within(polygon) and not > > polygon->Within(point) > > > > OGRLayer::SetSpatialFilter() > > > http://www.gdal.org/ogr/classOGRLayer.html#a0b4ab45cf97cbc470f0d60474d3e4169 > > > > On Fri, Jul 20, 2012 at 9:29 AM, Bui Chi Tai <taibc_coltech@>wrote: > > > > > > > > > -- > View this message in context: > http://osgeo-org.1560.n6.nabble.com/How-to-identify-a-point-is-belong-to-a-polygon-tp4989501p4989766.html > Sent from the GDAL - Dev mailing list archive at Nabble.com. > _______________________________________________ > gdal-dev mailing list > gdal-dev@lists.osgeo.org > http://lists.osgeo.org/mailman/listinfo/gdal-dev > -- Best regards, Chaitanya kumar CH. +91-9494447584 17.2416N 80.1426E
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