[GRASS-user] mapcalc problem in python script!!

GRASS GRASS user
1

Hey,

-------- Original-Nachricht --------

Datum: Fri, 4 Feb 2011 00:10:16 +0000
Von: Glynn Clements <glynn@gclements.plus.com>
An: grass-user@lists.osgeo.org
Betreff: Re: [GRASS-user] mapcalc problem in python script!!

Johannes Radinger wrote:

> Somehow I didn't your answer via email, I just found it at
> http://permalink.gmane.org/gmane.comp.gis.grass.user/38530

For whatever reason, GMX doesn't like my IP address, and bounces my
emails. The problem is compounded by a "feature" of the mailing list
software which (by default) doesn't send messages to any subscriber
whose email address appears in the To or CC fields (on the assumption
that they'll already get a copy). You can (and probably should)
disable this feature in your preferences (via the link at the bottom
of the email).

I don't know which feature to disable?!? And I don't know why gmx is bouncing your emails...strange somehow...

> just to give you some more information on my problem:
> I am running exactly following script:

> def main():
> grass.mapcalc("$upstream_shreve = ${upstream_part}+${shreve}",
> upstream_shreve = options['upstream_shreve'],
> upstream_part = options['upstream_part'],
> shreve = options['shreve'])
> return 0
>
> if __name__ == "__main__":
> options, flags = grass.parser()

grass.parser() needs to know the valid options for the script. These
are specified by comments beginning with "#%". See any existing script
for reference.

Then, you need to run the script with the appropriate command line
options. I'm assuming that isn't happening, because you should get an
error if you provide an unrecognised option (and there are no
recognised options).

I added your comments "#%" in the script (see attachment). Is it the only way to run the grass.mapcalc version in python with the grass.parser? I run my script external, directly from IDLE (without starting grass).
Has anyone wrote a python script for GRASS-Windows combination which is calling the mapcalculator and is totally outside of grass?

Just see my attached script.

cheers
johannes

--
Glynn Clements <glynn@gclements.plus.com>
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(attachments)

test3.py (1.55 KB)

2

Johannes Radinger wrote:

> > Somehow I didn't your answer via email, I just found it at
> > http://permalink.gmane.org/gmane.comp.gis.grass.user/38530
>
> For whatever reason, GMX doesn't like my IP address, and bounces my
> emails. The problem is compounded by a "feature" of the mailing list
> software which (by default) doesn't send messages to any subscriber
> whose email address appears in the To or CC fields (on the assumption
> that they'll already get a copy). You can (and probably should)
> disable this feature in your preferences (via the link at the bottom
> of the email).

I don't know which feature to disable?!?

Use the link at the bottom of the page to edit your subscription
options. The option in question is labelled "Avoid duplicate copies of
messages?", and should be set to "no".

> grass.parser() needs to know the valid options for the script. These
> are specified by comments beginning with "#%". See any existing script
> for reference.
>
> Then, you need to run the script with the appropriate command line
> options. I'm assuming that isn't happening, because you should get an
> error if you provide an unrecognised option (and there are no
> recognised options).

I added your comments "#%" in the script (see attachment). Is it the
only way to run the grass.mapcalc version in python with the
grass.parser? I run my script external, directly from IDLE (without
starting grass).

That won't work. Starting GRASS sets several environment variables
required by the GRASS libraries. If you want to be able to run GRASS
commands from anywhere, you will have to configure the environment
variables yourself.

The following is a minimal setup for Linux:

  export GISBASE=/opt/grass-7.0.svn
  export GRASS_PAGER=cat
  export GRASS_PYTHON=python
  export GRASS_MESSAGE_FORMAT=silent
  
  export PATH="$GISBASE/bin:$GISBASE/scripts:$PATH"
  export LD_LIBRARY_PATH="$GISBASE/lib"
  export GRASS_LD_LIBRARY_PATH="$LD_LIBRARY_PATH"
  export PYTHONPATH="$GISBASE/etc/python:$PYTHONPATH"
  
  export GIS_LOCK=$$
  export GRASS_VERSION="7.0.svn"
  
  tmp=/tmp/grass6-"`whoami`"-$GIS_LOCK
  export GISRC="$tmp/gisrc"
  mkdir "$tmp"
  cp ~/.grassrc6 "$GISRC"

On Windows, the paths will be different, and you need to set PATH
rather than LD_LIBRARY_PATH for the libraries.

The most important of the above are GISBASE, which must point to the
top-level GRASS installation directory, and GISRC, which must point to
a file containing settings for GISDBASE, LOCATION_NAME and MAPSET.

--
Glynn Clements <glynn@gclements.plus.com>