[Qgis-developer] grass module don't appear

[Vaclav Petras]

Please, keep the discussion on mailing list(s).

On Wed, Dec 9, 2015 at 9:14 AM, Giovanni Manghi <giovanni.manghi at gmail.com>
wrote:
> >
> > I was wrong, here is the necessary update for r.mapcalc:
> >
> > https://trac.osgeo.org/grass/changeset/67000
>
>
> I may have misunderstand the meaning of this new flag in the first
> place. In fact now I'm looking at it on GRASS svn I can't see on how
> it can help to get r.mapcalc in QGIS/Processing.

As far as I remember, the issue was that Processing didn't know the names
of the rasters user want to use in the calculation. r.mapcalculator was
working around this issue by separating the expression and raster names. -l
flag now tells the names to the caller without actually performing the
operation. There will be some special code needed in Processing (which
makes sense as r.mapcalc is special).

> The problem is that when using GRASS/Processing the layers are
> imported in a temporary location/mapset, and given temporary
> filenames, that are used as map names for input parameters.

I don't really follow you here but it seems to me that the issue might be
that -l still requires the rasters to exist. If this is the case please,
continue the discussion in GRASS ticket #2592.

https://trac.osgeo.org/grass/ticket/2592

> One question, why r.mapcalculator is not available in GRASS 7? I

I guess that simply nobody contributed a Python version of it. Bash scripts
are not guaranteed to work with G7 on MS Win, so the old script cannot be
used.

> haven't fiund any note about its removal in the changelog.

My impression is that it was never officially added in the first place, so
maybe that's the reason. Discussing this on the grass-dev mailing list or
in a ticket might be a good idea.

Best,
Vaclav
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