[GRASS-user] v.to.rast in a python loop, error
mlennert at club.worldonline.be
Thu Feb 9 04:41:39 EST 2012
On 08/02/12 13:09, Johannes Radinger wrote:
>> On 8 February 2012 11:35, Johannes Radinger<JRadinger at gmx.at> wrote:
>>> I try to run v.to.rast of a line in a loop
>>> to get a raster for each attribute of the vector (multiple columns).
>>> Therefore I created a short python script, which is working
>>> expept for that I am getting error messages:
>>> ERROR: option<output>:<raster_attribute> exists.
>>> Here the code:
>>> #!/usr/bin/env python
>>> import sys
>>> import grass.script as grass
>>> import grass.script.setup as gsetup
>>> def main():
>>> for i in ['FULL_HYDRO','LENGTH']:
>>> input = "streams at PERMANENT",
>>> output = "rast_"+i,
>>> type = "line",
>>> use = "attr",
>>> column = i)
>>> return 0
>>> if __name__ == "__main__":
>> Have you tried adding flags = '-o' as an argument to
>> grass.run_command? That will overwrite the output raster if it already
> I haven't tried yet to use the overwrite option. It'll probably work. It is just that I am wondering why these rasters "exist" although all rasters are entirely removed from the mapset.
> Can you reproduce this behaviour with that script and the North Carolina dataset?
I tried in 6.4.2RC2 and in 6.5svn and it works like a charm. Obviously,
if I try to run it a second time in the same mapset I get the output
exists errors (i.e. I have to manually erase them).
More information about the grass-user