The parameter ‘size’ in module r.param.scale defines the window size used to calculate DEM derivatives. It has a fixed maximum value of 69 defined in the line 18 of the header file ‘param.h’. I suggest that this value be changed to a somewhat higher value like 999 to allow the user to employ larger windows to calculate DEM derivatives. The software from which this module was derived (LandSerf) allows in its actual version any window size.
Unfortunately I have no experience with Grass development to help improve this module. I hope you can make this improvement.
Many thanks in advance.
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Alessandro Samuel-Rosa — PhD Candidate Graduate School in Agronomy - Soil Science Federal Rural University of Rio de Janeiro Seropédica, Rio de Janeiro, Brazil — Guest Researcher ISRIC - World Soil Information Wageningen, the Netherlands alessandro.rosa@wur.nl — Homepage: soil-scientist.net Skype: alessandrosamuel
On Mon, Feb 24, 2014 at 6:00 PM, Alessandro Samuel Rosa
<alessandrosamuel@yahoo.com.br> wrote:
Dear GRASS developers,
The parameter 'size' in module r.param.scale defines the window size used to calculate DEM
derivatives. It has a fixed maximum value of 69 defined in the line 18 of the header file 'param.h'.
I suggest that this value be changed to a somewhat higher value like 999 to allow the user to
employ larger windows to calculate DEM derivatives. The software from which this module was
derived (LandSerf) allows in its actual version any window size.
In general I don't see a reason to not increase the value (while not
having checked the code).
Likely the memory consumption will increase with larger moving window sizes.
Furthermore an "unlimited" size is probably geomorphometrical
nonsense, but I see that 69 is an arbitrary.
Did you actually try in your local installation a larger size?