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Mar
17
comment Overlay polygons on raster in different projections
Thanks for all the good points, really helpful. I am creating the raster myself as well, so I have the option of reprojecting the points to a projected coordinate system before interpolating the raster, and I want to know if this would be a "better" result or just a "slightly different" one. My original data is points in latlong (near Brisbane actually!) but within a small enough area that I could use MGA56. It sounds like this would not give a better result and I can stick with latlong.
Mar
17
comment Overlay polygons on raster in different projections
So the cells change ever so slightly? I can see that the reprojected raster does not overlap exactly with the original, while the reprojected vector does. My theory is that this affects which cells are considered to be inside the polygon by the overlay algorithm. For the case I'm comparing, the polygons are fairly small compared to the grid size (5-6 grid cells per polygon), which might increase the effect.
Mar
17
asked Overlay polygons on raster in different projections
Aug
18
awarded  Caucus
Aug
18
awarded  Constituent
Mar
25
answered gdalwarp from within python script misbehaving
Jun
4
answered How can I convert a ascii file to geotiff using Python?
May
27
answered Python GDAL: degrees to meters without reprojecting
May
21
awarded  Commentator
May
21
comment Python to get ids from shp dont return all records
@user1573901: no problem! Please consider accepting the answer (click the tick mark under the down arrow) if it solved your problem.
May
20
answered Python to get ids from shp dont return all records
Apr
17
comment Why do ECWs go missing when exporting MXD to PDF with ArcPy?
Thanks, I suspected it was a memory issue. This is good for explaining, but I still don't understand why it happens externally but not within ArcGIS.
Apr
16
asked Why do ECWs go missing when exporting MXD to PDF with ArcPy?
Apr
8
awarded  Enlightened
Apr
8
awarded  Nice Answer
Apr
8
awarded  Yearling
Apr
8
awarded  Teacher
Apr
8
answered How to save python session in QGIS?
Jan
30
comment How do I get the pixel value of a GDAL raster under an OGR point without NumPy?
This is amazing. Thanks!
Jan
18
comment how to overlay shapefile and raster?
I went with this approach, though the function name is actually "Grid Statistics for Polygons".