Hi all, I try to calculate the slope at precise points by intersection between a vector layer of points and a raster DEM (both with the same SRID). I would like to get the result in percent, giving the slope on each point of my vector layer.
Here is the query I use : SELECT p.id, p.x, p.y, ST_Value(ST_Slope(m.rast, 1, '32BF', 'PERCENT'), p.geom, TRUE)::FLOAT8 AS slope FROM mypoints p INNER JOIN myDTM m ON ST_Intersects(m.rast, p.geom) ORDER BY p.id; Is this query OK ? When I compare its results with the same intersection in Arcgis 9, I get a bias showing 5% between Arcgis and PostGIS 2.1 (Arcgis gives higher slopes than PostGIS, the highest gap being 97%). Thanks for you help. Sincerely, Cedric -- View this message in context: http://postgis.17.x6.nabble.com/Slope-calculation-by-intersection-between-points-and-DTM-tp5005934.html Sent from the PostGIS - User mailing list archive at Nabble.com. _______________________________________________ postgis-users mailing list [email protected] http://lists.osgeo.org/cgi-bin/mailman/listinfo/postgis-users
