Hi Frank, The distance is according to ArcGIS 500m. According to Python(OGR) 29215.31. I was thinking the same, that GDAL gives the distance according to the Geographic Coordinate System. Is there a way it uses the units of the Projected Coordinate System (which would be meters)? Or do you know of another workaround to get the result in meters?
Best, Uli 2013/3/6 Frank Warmerdam <[email protected]> > Uli, > > You might want to elaborate on in what ways the results differ. Perhaps > for a concrete example pair of geometries. The GDAL/OGR Distance is going > to give planar distance in "decimal degrees" if everything is in geographic > coordinates without regard to ellipsoidal geometries. I suspect the ArcGIS > algorithm is actually giving a distance in meters - possibly for the great > circle path from the closest points. If that is what you need, a different > approach will be needed. > > Best regards, > Frank > > On Wed, Mar 6, 2013 at 2:49 PM, Uli Strötz <[email protected]> wrote: > >> >> I want to determine the shortest distance between a point and a line. >> I use the following Python script to do so. If I compare the result of the >> script with the result of ArcMap's Near Analysis, I get a completely >> different results. The shapefiles are in the CRS GCS_North_American_1983 >> and projected with Albers. What could be the reason for the difference? >> >> import ogr >> >> driver = ogr.GetDriverByName('ESRI Shapefile') >> >> lineshp = driver.Open('U:/My Documents/Tool/shp/line.shp', 0) >> linelyr = lineshp.GetLayer() >> >> pointshp = driver.Open('U:/My Documents/Tool/shp/point.shp', 0) >> pointlyr = pointshp.GetLayer() >> >> line = linelyr.GetNextFeature() >> point = pointlyr.GetNextFeature() >> >> line_geom = line.GetGeometryRef() >> point_geom = point.GetGeometryRef() >> >> dist = point_geom.Distance(line_geom) >> >> print dist >> >> Thanks ahead! >> >> Uli >> >> >> _______________________________________________ >> gdal-dev mailing list >> [email protected] >> http://lists.osgeo.org/mailman/listinfo/gdal-dev >> > > > > -- > > ---------------------------------------+-------------------------------------- > I set the clouds in motion - turn up | Frank Warmerdam, > [email protected] > light and sound - activate the windows | http://pobox.com/~warmerdam > and watch the world go round - Rush | Geospatial Software Developer >
_______________________________________________ gdal-dev mailing list [email protected] http://lists.osgeo.org/mailman/listinfo/gdal-dev
