[Qgis-developer] Problem with GRASS Region Extent and Region Cellsize on Processing

gene martin.laloux at gmail.com
Fri Mar 11 00:17:59 PST 2016

You can control  what the algorithm  is doing by viewing  the resulting files

-  /.../.qgis2/processing/grass_batch_job.sh (or .bat) for GRASS 6.4.x
-  /.../.qgis2/processing/grass7_batch_job.sh (or .bat) for GRASS 7.x

They are created by the scripts 
/..../python/plugins/processing/algs/grass/GrassUtils.py and

The scripts use the  subprocess
<https://docs.python.org/2/library/subprocess.html>   module to execute
these  GRASS commands

1) They first create a temporary GRASS LOCATION (temp_location) and two
temporary MAPSETS (PERMANENT and user) 
2) They fix also a temporary REGION and write the desired GRASS commands
3) They execute the resulting GRASS script with subprocess

Example of a grass_batch_job.sh  script

      g.proj -c proj4="+proj=utm +zone=30 +ellps=intl
+towgs84=-87,-98,-121,0,0,0,0 +units=m +no_defs"
      v.in.ogr min_area=0.0001 snap=-1
layer=points output=tmp145728617122 --overwrite -o
     g.region -a n=4458983.8488 s=4458921.97814 e=270855.745301
w=270778.60198 res=100
     v.voronoi  input=tmp145728617122
output=outpute45d311cf9da4a6491d241312f11ba92 --overwrite
     v.out.ogr -s -e input=outpute45d311cf9da4a6491d241312f11ba92 type=auto
format=ESRI_Shapefile output_layer=output --overwrite

What happens when you fix the GRASS Region Extent and Region Cellsize option
You can also run this script directly in GRASS GIS

View this message in context: http://osgeo-org.1560.x6.nabble.com/Problem-with-GRASS-Region-Extent-and-Region-Cellsize-on-Processing-tp5255693p5255773.html
Sent from the Quantum GIS - Developer mailing list archive at Nabble.com.

More information about the Qgis-developer mailing list