[STATSGRASS] Change of spatial support

[Ulrich Leopold]

On Wed, April 5, 2006 13:57, Edzer J. Pebesma wrote:
> Ulrich Leopold wrote:
>> Dear list,
>> I am trying to change the spatial support (grid size) of some floating
point
>> raster maps from 250x250m to 1000x1000m. It's a kind of upscaling or more
preciseley aggregation.
>> All I need to do is to superimpose the larger grid on the smaller grid and
compute the average and variance for the larger grid from the 4x4 250m
cells
>> located within one 1000m cell.
>> I recognise that this is still not possible in GRASS. The GRASS resampling
methods for change of resolution, such as r.neigbors or g.region are not an
option as they do not provide a simple averaging method and the aggregation
error (variance).
>> I thought maybe r.mapcalc or R with it's grass6 interface could be used.
But
>> I
>> do not know how to achieve it in terms of code. Any sugegstions? Ulrich

> I think you can do this in R, but also think that you're primarily looking
for a
> GRASS solution. Am I right?
> --
> Edzer

I am also happy to solve this in R. It might be even more appropriate as you
caould caluclate also other summary statistics. I just do not know what kind
of approach to use as I need a kind of jumping window for my raster map in
which I can perform some statistical calculation.

Are there already functions available in the spatial pckages of R? Or is it
fairly easy to write an new function for that?

Ulrich