[GRASS-user] r.shade python issues

[Laurent C.]

Hello,

I answered off-list by mistake.

Normally, when "non-zero return code1" occurs, you can see the error
generated by the module on the terminal.
Alternatively, you can try the solution given in the wiki to retrieve the error:

def read2_command(*args, **kwargs):
   kwargs['stdout'] = grass.PIPE
   kwargs['stderr'] = grass.PIPE
   ps = grass.start_command(*args, **kwargs)
   return ps.communicate()

Could you check this out and post the result here?

Regards,
Laurent

2016-05-23 9:58 GMT-05:00 Gareth Grewcock <garethgrewcock at gmail.com>:
> Thanks for getting in touch Laurent.
>
> I have been working on a data processing script written in python which I
> want to use Grass modules in. So I have actually been using
> gscript.run_command() already. I was doing this externally and not actually
> loading Grass explicitly. I can do this successfully as follows:
>
> grass.run_command('r.in.gdal',input = ffile, output = name, quiet = 'True',
> overwrite = 'True', flags = 'o')
>
> grass.run_command('r.relief',input = name,output = hillshade_output,altitude
> = '20', azimuth = '315', zscale = '6', overwrite = 'True')
>
> grass.run_command('r.slope.aspect',elevation = name, slope = "dem_slope",
> aspect = "dem_aspect", overwrite = 'True')
>
> However, when I come to use r.shade, I get the 'non-zero return code1', so I
> have since gone back into the Grass UI to try and simply run python snippets
> but can't get r.shade to work with Python either externally or through the
> UI, I really have no idea what the problem is as all of the other modules
> work fine.
>
> Cheers,
>
> Gareth
>
> On Mon, May 23, 2016 at 3:38 PM, Laurent C. <lrntct at gmail.com> wrote:
>>
>> Hello,
>>
>> Try this:
>>
>> import grass.script as gscript
>> gscript.run_command("r.shade", shade=aspect, color=elevation,
>> output=elevation_aspect_shaded)
>>
>> Have a look at the wiki:
>> https://grasswiki.osgeo.org/wiki/GRASS_Python_Scripting_Library
>>
>> Laurent
>>
>> 2016-05-23 8:01 GMT-05:00 Gareth Grewcock <garethgrewcock at gmail.com>:
>> > Hi Stefan - thanks for getting back to me.
>> >
>> > I had tried that before but still got issues, this time returning:
>> > 'NameError: name 'r' is not defined'
>> >
>> > r.shade(shade=aspect, color=elevation, output=elevation_aspect_shaded)
>> > Traceback (most recent call last):
>> >   File "<input>", line 1, in <module>
>> > NameError: name 'r' is not defined
>> >
>> > Any ideas what might be causing that?
>> >
>> > Cheers,
>> > Gareth
>> >
>> > On Mon, May 23, 2016 at 12:47 PM, Blumentrath, Stefan
>> > <Stefan.Blumentrath at nina.no> wrote:
>> >>
>> >> Hei,
>> >>
>> >>
>> >>
>> >> Maybe the issue is missing commas?
>> >>
>> >>
>> >>
>> >> r.shade(shade=aspect, color=elevation, output=elevation_aspect_shaded)
>> >>
>> >>
>> >>
>> >> Cheers
>> >>
>> >> Stefan
>> >>
>> >>
>> >>
>> >> From: grass-user [mailto:grass-user-bounces at lists.osgeo.org] On Behalf
>> >> Of
>> >> Gareth Grewcock
>> >> Sent: 23. mai 2016 11:49
>> >> To: grass-user at lists.osgeo.org
>> >> Subject: [GRASS-user] r.shade python issues
>> >>
>> >>
>> >>
>> >> Hi – I’m having issues with r.shade module in grass 7.0.3 when trying
>> >> to
>> >> interact with data via python.
>> >>
>> >>
>> >>
>> >> r.shade runs absolutely fine through the UI, however, when I run the
>> >> syntax through the python console, I get a syntax error.
>> >>
>> >>
>> >>
>> >> I have tried a variety of different datasets and syntax but it keeps
>> >> coming back with the syntax error, I went back to manual for the basics
>> >> but
>> >> I still get the following:
>> >>
>> >>
>> >>
>> >> r.shade shade=aspect color=elevation output=elevation_aspect_shaded
>> >>
>> >>   File "<input>", line 1
>> >>
>> >>     r.shade(shade=aspect color=elevation
>> >> output=elevation_aspect_shaded)
>> >>
>> >>                              ^
>> >>
>> >> SyntaxError: invalid syntax
>> >>
>> >>
>> >>
>> >> Other modules (r.in.gdal, r.relief, r.slope.aspect, g.region etc) all
>> >> run
>> >> fine through python, I am only having issues with r.shade.
>> >>
>> >>
>> >>
>> >> Does anybody have any idea what might be going wrong?
>> >>
>> >>
>> >>
>> >> Cheers,
>> >>
>> >> Gareth
>> >>
>> >>
>> >
>> >
>> >
>> > _______________________________________________
>> > grass-user mailing list
>> > grass-user at lists.osgeo.org
>> > http://lists.osgeo.org/mailman/listinfo/grass-user
>
>