[Qgis-developer] GRASS Direct

[Radim Blazek]

On Mon, Dec 10, 2012 at 9:53 PM, John C. Tull <jctull at gmail.com> wrote:
> On Dec 10, 2012, at 12:44 PM, Radim Blazek <radim.blazek at gmail.com> wrote:
>
>> The GRASS Direct is an environment developed within QGIS GRASS
>> plugin/provider which makes it possible to run GRASS raster modules
>> without GRASS mapset and without data conversion to GRASS format.
>> Basically it is a library implementing GRASS data read/write function
>> which is using QGIS providers to read/write data. In direct mode, the
>> GRASS modules are run with this library instead of  the standard GRASS
>> gis library.
>>
>> The GRASS modules may be run in direct mode from GRASS Tools (which
>> are now always enabled) if no mapset is opened. The interface is
>> similar to the standard GRASS Tools apart that the region is selected
>> in combo box in top of options (to be discussed) and the output is a
>> GeoTIFF file. It is also possible to run GRASS modules in direct mode
>> from a shell if some environment variables are set. You can see those
>> variables printed in top of the output tab.
>>
>> This is work in progress, so I was reluctant to announce that but
>> because it had caused some compilation problems, it was necessary to
>> explain a bit how it works. Currently there are only few modules
>> enabled and you can find various problems. Especially it was only
>> tested on Linux and most probably more fixes will be necessary on Mac
>> and Windows.
>>
>> I believe that GRASS Direct could also be used in SEXTANTE with a
>> little work. It would be necessary however to distinguish modules
>> which may be run in direct mode from those which may not (mostly
>> vector modules).
>>
>> Sorry for the problems I caused on Mac and Windows and many thanks to
>> Jürgen and Larry for fixes.
>>
>> Radim
>
> Hi Radim,
>
> This is a great new addition to QGIS, so thank you for you work on it.
>
> I wanted to bring my comment I made elsewhere on my Mac testing into this, more appropriate thread:
>
> I just tested one of the available modules on a local DEM file, and here is there error message that appeared when I ran it:
>
> Cannot start module r.slope.aspect
> command: /usr/local/Cellar/grass/6.4.2/grass-6.4.2/bin/r.slope.aspect --interface-description
>
> ERROR: GISRC - variable not set
>
> Note that I am running a version of grass installed locally, not from the application that William makes available.

If you get such error it means that the fake library was not found
(standard grass_gis library is complaining about missing environment).
The problem was that DYLD_LIBRARY_PATH was not set. Please try again
with master.

Radim

> Cheers,
> John
>