[GRASS-user] r.viewshed Python Script OSError

Martin Lacayo mlacayo at stanford.edu
Wed May 29 13:06:56 PDT 2013

Hi Markus,

Thank you for the link, that is very helpful.

I would prefer to use SEXTANTE over GRASS since it also gives access
to other tools as well, but so far I have had more luck with GRASS. I
will post an update once one of these approaches works.

I've compiled and installed GRASS 6.4.3RC3 from source, but now I'm
having trouble installing the r.viewshed extension.

I'm getting the following error:

make: *** No rule to make target `/usr/local/grass-6.4.3RC3/
lib/libgrass_iostream.6.4.3RC3.a', needed by
cloos/10168.0/r.viewshed/bin/r.viewshed'.  Stop.
ERROR: Compilation failed, sorry. Please check above error messages.
(Wed May 29 11:53:36 2013) Command finished (7 sec)

As a test I tried installing g.md5sum and r.area, which installed
without problems.

Any suggestions?


On Tue, May 28, 2013 at 11:20 AM, Markus Metz
<markus.metz.giswork at gmail.com> wrote:
> On Tue, May 28, 2013 at 7:09 PM, Martin Lacayo <mlacayo at stanford.edu> wrote:
>> Hi Markus,
>> I did install r.viewshed (it is located in ~/.grass6/addons/), and the
>> full path does appear in $PATH.
>> I am executing the Python script from outside of GRASS. Is this
>> normal? I am hoping for some advice on this.
> You need to execute the Python script from within GRASS, or set some
> environment variables first, see [1]. Within your script, you could
> also first use a dummy location, for example the GRASS demolocation,
> then create a new location with the projection information in the
> raster map to be used as input for r.viewshed, change to that
> location, import the raster map, run r.viewshed, export the result.
> This is essentially what the SEXTANTE plugin in QGIS is doing.
>> The intent is to liberate
>> some software (naturalcapitalproject.org) from ArcGIS for users on
>> Windows.
> Nice!
>> When I start GRASS (in text mode) it says "Welcome to GRASS 6.4.2 (2012)."
> If possible, update to GRASS 6.4.3.
> HTH,
> Markus M
> [1] http://grasswiki.osgeo.org/wiki/Working_with_GRASS_without_starting_it_explicitly
>> Thank you,
>> Martin
>> On Sun, May 26, 2013 at 1:27 PM, Markus Metz
>> <markus.metz.giswork at gmail.com> wrote:
>>> On Fri, May 24, 2013 at 11:32 PM, Martin Lacayo <mlacayo at stanford.edu> wrote:
>>>> Hello,
>>>> I am using GRASS 6.4 on Debian. I am trying to make a call to
>>>> r.viewshed from Python, but it fails with the following exception:
>>>> OSError: [Errno 2] No such file or directory
>>>> Any suggestions?
>>> Did you install r.viewshed?
>>> Where is the r.viewshed binary?
>>> Is the location of r.viewshed in the PATH (within GRASS, test with
>>> "echo $PATH")?
>>> Did you execute the python script from within GRASS?
>>> Which GRASS 6.4 version are you using? Recommended is 6.4.3.svn.
>>> Markus M

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