[Qgis-user] Stratified stats of Raster map by vector map in QGIS?

[Carson Farmer]

Agus,
> Given a vector map (i.e., a land cover map)
> and a raster of a continuous variable (i.e., height),
> is there any plugin calculating a table of average
> (and perhaps other stats) of the raster for
> each category in the vector?
I don't know of any plugins that will do this directly, but here is one 
possible solution:

If you are able to convert your raster to points (i.e. extract the 
centre of each raster cell as a point), then you could use the 'Join 
attributes by location' tool in fTools to extract the info that you need 
(and you can opt to calculate the mean values).

Hope this helps,

Carson

-- 
Carson J.Q. Farmer
PhD Fellow
National Centre for Geocomputation (NCG),
John Hume Building,
National University of Ireland, Maynooth,
Co. Kildare,
Ireland.
http://www.carsonfarmer.com
http://www.ftools.ca