[GRASS-dev] r.resample.rst behavior does not match manual

[Markus Neteler]

On Mon, Aug 31, 2015 at 1:55 AM, Michael Barton <Michael.Barton at asu.edu> wrote:
> Thanks for the clarification Stefan.
>
> It sounds like, unlike other resampling commands (unless they, too, are in
> error), r.resample.rst needs to be run at the resolution of the original
> map, not the output map.

Yes. It has been implemented like that (not sure if there is any
technical reason), yet going a bit against the "normal" workflow.

> The output resolution will be determined by the
> command, not by the region settings. This should go into the manual too,
> along with the revised text you suggested.

Stefan, Michael, please send a text snipped to me for the manual.

> In a somewhat related question, do you have any idea how r.resample.filter
> works? The manual is not very informative

True - thanks to my long term inbox I found material here
https://trac.osgeo.org/grass/ticket/1401#comment:8

and merged it into the manual page:
https://grass.osgeo.org/grass70/manuals/r.resamp.filter.html
https://grass.osgeo.org/grass71/manuals/r.resamp.filter.html

(please revise as needed).

> and I couldn’t get any useful
> downscaling results (lower to higher resolution) with my spot tests.

Adding some examples there would be important.

> r.resample.interp doesn’t seem to give expected results either. I’ll do a
> test with demo data when I have a few minutes this week. I did get very good
> downscaling results with r.resample.bspline, but it took a very long time.

Perhaps time to expand
https://grasswiki.osgeo.org/wiki/Interpolation#Resampling_of_raster_maps_to_finer_resolution
?

Markus