[GRASS-dev] question about any July changes in hydrology functions

[Michael Barton]

Thanks Glynn. We'll certainly give it a try.

Michael


On 8/3/07 3:18 AM, "Glynn Clements" <glynn at gclements.plus.com> wrote:

> 
> Michael Barton wrote:
> 
>>>> 1. Is there any speed advantage/disadvantage to using r.mfilter over
>>>> r.neighbors? At the moment, because we are trying to get rid of occasional
>>>> spikes, I don't think that a weighted mean will give better results than an
>>>> unweighted mean. But the only way to get functions like a weighted mean is
>>>> to use r.mfilter, so it would be good to know if there are any known
>>>> performance hits or if it is faster.
>>> 
>>> r.mfilter currently works with integers. AFAICT, there's no
>>> fundamental reason why it can't be upgraded to FP.
>> 
>> Then, as is it won't work for us. If it can be upgraded to integers we can
>> try it.
> 
> I've added an FP version, r.mfilter.fp.
> 
> I didn't modify r.mfilter as it turns out that there is some behaviour
> which is specific to integer maps, and to the zero-is-null behaviour
> of 4.x. It wasn't practical to add support for FP and null values
> without breaking compatibility.

__________________________________________
Michael Barton, Professor of Anthropology
Director of Graduate Studies
School of Human Evolution & Social Change
Center for Social Dynamics & Complexity
Arizona State University

phone: 480-965-6213
fax: 480-965-7671
www: http://www.public.asu.edu/~cmbarton