[GRASS-user] r.mfilter produces empty result

[Anna Petrášová]

On Thu, May 11, 2017 at 10:15 AM, Luí­s Moreira de Sousa
<luis.de.sousa at protonmail.ch> wrote:
> Hi Anna, thanks for the help. I can not post the DEM to the list, here is a
> link to Dropbox:

It seems the problem is in the filter specification:

TITLE 3x3 High Pass
MATRIX 3
-1 -1 -1
-1  8 -1
-1 -1 -1
DIVISOR 9
TYPE S

If you change it to TYPE P it will work. S is 'sequential':

Sequential filtering happens in place. As the filter is applied to the
raster map layer, the category values that were changed in neighboring
cells affect the resulting category value of the current cell being
filtered.

So since you have nulls all around it it probably propagates the
nulls. I am not sure if it's a bug. Is the S type required for your
analysis?

Anna

>
> --
> Luís Moreira de Sousa
> Im Grund 6
> CH-8600 Dübendorf
> Switzerland
>
> Phone: +41 (0)79 812 62 65
> Email: luis.de.sousa at protonmail.ch
> URL: https://sites.google.com/site/luismoreiradesousa
>
>
> -------- Original Message --------
> Subject: Re: [GRASS-user] r.mfilter produces empty result
> Local Time: 11 May 2017 3:56 PM
> UTC Time: 11 May 2017 13:56
> From: kratochanna at gmail.com
> To: Martin Landa <landa.martin at gmail.com>
> Luí­s Moreira de Sousa <luis.de.sousa at protonmail.ch>,
> grass-user at lists.osgeo.org <grass-user at lists.osgeo.org>
>
> On Thu, May 11, 2017 at 3:47 AM, Martin Landa <landa.martin at gmail.com>
> wrote:
>> Hi,
>>
>> 2017-05-11 9:36 GMT+02:00 Luí­s Moreira de Sousa
>> <luis.de.sousa at protonmail.ch>:
>>>> r.mfilter input=blenddem output=blenddem.highpass filter=highpass9.txt
>>> 100%
>>> Writing raster map <blenddem.highpass>
>>
>> did you set up correctly computational region?
>>
>> g.region raster=blenddem
>>
>> Ma-
>>
>
> https://gis.stackexchange.com/questions/239556/r-mfilter-produces-empty-result
>
> From the GIS SE question it seems everything is correctly set. In that
> case, could you provide us with your data to test it? You can send a
> link to it, offlist if you need to.
>
> Anna
>
>> --
>> Martin Landa
>> http://geo.fsv.cvut.cz/gwiki/Landa
>> http://gismentors.cz/mentors/landa
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>
>