[GRASSLIST:1088] Re: Reproject raster data - weighted average

[Rado Bonk]

David,

You may try to use r.statistics to compute average values before you
reproject your data (method=average) Something like:

1. Prepare new map (X)  in your lat./long. location with the desired
resolution, lower than original - larger pixel size (g.region, r.mapcalc
may be used)

2.Run in your lat./long.
 r.statistics cover=Y base=X method=average output=N

N - new map with average of Y values based on X.

3. r.proj

Cheers,

Rado



Dňa Ut, 2003-09-02 at 11:08, David Orme napísal:
> Hi,
> 
> I have some floating point raster data sets in a lat/long location. I 
> want to reproject these data into a cylindrical equal area location. 
> Obviously I can do this using `r.proj'  but I want the values of cells 
> in the reprojected map to be calculated as averages of the 
> corresponding cells in the original projection, weighted by their 
> relative area in the new grid cells.
> 
> Is there any way to do this in Grass?
> 
> Thanks,
> David
-- 
Radoslav Bonk M.S.
Dept. of Physical Geography and Geoecology
Faculty of Sciences, Comenius University
Mlynska Dolina 842 15, Bratislava, SLOVAKIA
tel: +421 905 968 127 e-mail: rbonk at host.sk