Polygon density

Question

Hi,
I need to overlap a grid over the polygon layer and calculate the sum of polygon areas for each cell. The output should be a raster layer. So, I have only polygon layer and need to create raster showing sum of areas in each cell.
The problem is similar to LineDensity tool for lines, but I can't find the appropriate tool for polygons.

Thanks for your suggestions,

JeffreySwain · Answer

Not to break up the Transformer party, but perhaps the zonal tools may yield an answer.  Dare I say, "they are more than meets the eye."

I am not sure what you mean by "sum of polygon areas for each cell."  The Zonal tools can generate a raster output based on a 'zone' or polygon/raster, but to find the number of polygons per cell makes me think you have a rather larger cell for the raster or tiny polygons.  Based on what I think you mean, I would recommend the Zonal Statistics and choose "sum."

BruceNielsen · Answer

BTW, not sure if I understand that Dodt's opinion of Python - sounds like criticism. If that's so, I strongly dissagree :-))

Best,

Believe me, it's not a criticism. He's making the point that Python is far superior to BASIC (and a lot of other languages IMHO) by orders of magnitude. To fully appreciate Optimus Prime's abilities relative to those of a pickup, view one of the Transformers movies.

MatejTacer · Answer

Thank you, Bruce!
That's what I've resorted to:
I created grid using python and osgeo.ogr, union and area calculation are yet to be done. Python comes in handy since I need to do it for 1000+ layers.
BTW, not sure if I understand that Dodt's opinion of Python - sounds like criticism. If that's so, I strongly dissagree :-))

Best,