[GRASS-dev] Avoiding maximum open files limit in r.series

Sören Gebbert soerengebbert at googlemail.com
Wed Oct 5 06:21:14 EDT 2011

Dear devs,
just for your information, i have added the support of input files
with newline separated map names to r.series.
r.series now supports two input methods, file and input. Using option
<file> is slower but avoids the open file descriptor limit.

Now we can process ten-thousands of maps with r.series without hitting
the open file descriptor limit or the maximum command line size limit.
Limiting factor is now the RAM.

I have tested r.series with ~6000 maps (ECA&D daily temperature data
from 1995-2010) each ~100000 cells. Computation needs for method
about 3 minutes on my (fast) machine.
Memory footprint is about 330MB of RAM. But this looks like a memory
leak  to me, because the memory consumption raise linear with the
processed rows of the output map. All the memory allocation in
r.series is done before the row processing ... ???


The changes includes also some tests and the temporal module tr.series.

Best regards

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