[GRASS-user] Grass, Python, mapcalc

[Paul Meems]

Here I am again with some questions ;)

I'm now trying to use r.sun and r.mapcalc with Python to create my annual
solar radiation map.
I'm using the Python shell inside GRASS.

For testing purposes I start with 9 days.
The r.sun part seems to be working:
for x in range(1, 10, 1):
    print "Working on day %d" % (x)
    glob_rad = 'global' + str(x)
    grass.run_command('r.sun', flags = 's', elevin = 'w001001 at temp', aspin
= 'aspect at temp', slopein = 'slope at temp', glob_rad = glob_rad, day = x)
I do have a question about parsing the --overwrite flag. How to do that.
Adding flags='s, --overwrite' or flags='s, -overwrite' gives a compile
error.

Now I try to combine the results of r.sun into 1 raster.
This is working:
for x in range(1, 10, 1):
    if x == 2:
      exp = 'sun = global1 at temp + global2 at temp'
      print exp
      grass.mapcalc(exp, quiet=False, verbose=False, overwrite=True)

This is also working:
for x in range(1, 10, 1):
    if x == 2:
      exp = 'sun = global1 at temp + global2 at temp'
      print exp
      grass.mapcalc(exp, quiet=False, verbose=False, overwrite=True)
    elif x > 2:
      exp = 'sun = sun at temp + global' + str(x) + '@temp'
      print exp
and produces this output:
sun = sun at temp + global3 at temp
sun = sun at temp + global4 at temp
sun = sun at temp + global5 at temp
sun = sun at temp + global6 at temp
sun = sun at temp + global7 at temp
sun = sun at temp + global8 at temp
sun = sun at temp + global9 at temp
But when I execute this using
grass.mapcalc(exp, quiet=False, verbose=False, overwrite=True)
 Grass crashes completely.

Has this something to do with having the output file is the input file as
well?
If this is not allowed how can I combine all output files from r.sun into 1
raster?

Thanks,

Paul
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