[gdal-dev] Raster algebra with Gdal and Python

[Zoltan Szecsei]

Alexander Bruy wrote:
> Hi again,
>
> with your help I've fix problem with "integer overflow" and now I get
> correct results.
>
> Also I clean up my code for reduce memory usage but problem with large files is
> remain. I have raster with size 11779*10663 and 5 bands. When I calculate NDVI
> on Linux box (2 Gb RAM, 2Gb swap, GDAL 1.6.3) all works fine and I get correct
> results.Peak memory consumption during this operation is 1900 Mb RAM and
> 300 Mb swap (monitored with htop).
>
> When I run same code with same raster on Windows box (2 Gb RAM, swap size is
> selected by OS ~1.3 Gb, GDAL 1.6.3) I get MemoryError. Peak memory consumption
> during this operation is 600 Mb RAM and 700 Mb swap. I've try smaller
> raster with size
> 8500*7600 pixels but get MemoryError too.
>
>   
Hi,
I'll bet the problem is that you are hitting the normal 2GB user address 
space in Windows.
Google for "/3GB" and you will find how to increase this to 3GB.
I can't tell you outright because you have not mentioned whether you are 
using XP or VISTA/Win7 - there are different ways to do it for these OS 
versions.
You will have to re-boot after changing the relevant boot.ini or 
whatever file.


HTH,
Zoltan


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Zoltan Szecsei
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