[GRASS-dev] grass python problem

GRASS GRASS developer
1

Hi Everyone

Hope this email finds you well.
I can run r.cross in console with following command:
“r.cross -z --overwrite --quiet input=Connect_Lake@PERMANENT,str_grass_r@PERMANENT output=test”

But I got error by run r.cross in python with following command:
grass.run_command(‘r.cross’, input = [‘str_grass_r@PERMANENT’,‘Connect_Lake@PERMANENT’],output = ‘test’, quiet = True)

What is the correct format to use r.cross function in Python? and how to obtain the output table generated by r.cross?

Thanks
Ming

2

Please provide more information:
GRASS version
Python version
exact error message

I did not observe any errors while running command you provided (of
course I used different map names to match map names I had on my
system).
Māris.

otrd., 2020. g. 17. nov., plkst. 06:04 — lietotājs ming han
(<dustming@gmail.com>) rakstīja:

Hi Everyone

    Hope this email finds you well.
    I can run r.cross in console with following command:
    "r.cross -z --overwrite --quiet input=Connect_Lake@PERMANENT,str_grass_r@PERMANENT output=test"

    But I got error by run r.cross in python with following command:
    grass.run_command('r.cross', input = ['str_grass_r@PERMANENT','Connect_Lake@PERMANENT'],output = 'test', quiet = True)

     What is the correct format to use r.cross function in Python? and how to obtain the output table generated by r.cross?

Thanks
Ming

3
···

On 11/17/20 6:03 AM, ming han wrote:

Hi Everyone

Hope this email finds you well.
I can run r.cross in console with following command:
“r.cross -z --overwrite --quiet input=Connect_Lake@PERMANENT,str_grass_r@PERMANENT output=test”

But I got error by run r.cross in python with following command:
grass.run_command(‘r.cross’, input = [‘str_grass_r@PERMANENT’,‘Connect_Lake@PERMANENT’],output = ‘test’, quiet = True)

What is the correct format to use r.cross function in Python? and how to obtain the output table generated by r.cross?

This worked fine for me also, using GRASS 7.8.4 in the nc_basin_spm LOCATION:

In [2]: import grass.script as gscript

In [3]: gscript.run_command("r.cross", input=["landuse@PERMANENT","basins@PERMANENT"], output="lu_bas", overwrite=True)
r.cross: STEP 1 ...
100%
r.cross: STEP 2 ...
r.cross: STEP 3 ...
100%
Creating support files for <lu_bas>...
89 categories
Out[3]: 0

Just to be clear, you do not get a table output, rather a raster. In your case you should see a new raster “test”.

Thanks
Ming

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-- 
Micha Silver
Ben Gurion Univ.
Sde Boker, Remote Sensing Lab
cell: +972-523-665918
4

Hi Everyone

Thanks for your response, for some reason it works now.

Thanks
Ming

Micha Silver <tsvibar@gmail.com> 于2020年11月17日周二 上午10:44写道：

On 11/17/20 6:03 AM, ming han wrote:

Hi Everyone

Hope this email finds you well.
I can run r.cross in console with following command:
“r.cross -z --overwrite --quiet input=Connect_Lake@PERMANENT,str_grass_r@PERMANENT output=test”

But I got error by run r.cross in python with following command:
grass.run_command(‘r.cross’, input = [‘str_grass_r@PERMANENT’,‘Connect_Lake@PERMANENT’],output = ‘test’, quiet = True)

What is the correct format to use r.cross function in Python? and how to obtain the output table generated by r.cross?

This worked fine for me also, using GRASS 7.8.4 in the nc_basin_spm LOCATION:

In [2]: import grass.script as gscript

In [3]: gscript.run_command("r.cross", input=["landuse@PERMANENT","basins@PERMANENT"], output="lu_bas", overwrite=True)
r.cross: STEP 1 ...
100%
r.cross: STEP 2 ...
r.cross: STEP 3 ...
100%
Creating support files for <lu_bas>...
89 categories
Out[3]: 0

Just to be clear, you do not get a table output, rather a raster. In your case you should see a new raster “test”.

Thanks
Ming

_______________________________________________
grass-user mailing list
[grass-user@lists.osgeo.org](mailto:grass-user@lists.osgeo.org)
[https://lists.osgeo.org/mailman/listinfo/grass-user](https://lists.osgeo.org/mailman/listinfo/grass-user)

-- 
Micha Silver
Ben Gurion Univ.
Sde Boker, Remote Sensing Lab
cell: +972-523-665918