[Numpy-discussion] Issues with the memmap object

Mike Ressler mike.ressler@alum.mit....
Mon Jun 18 14:24:37 CDT 2007


What versions of python and numpy are you using?

On 6/18/07, Sturla Molden <sturla@molden.no> wrote:
> Problem 3: No 64 bit support on Windows or Linux:
>
> On Linux, large files must be memory mapped using mmap64 (or mmap2 if 4k
> boundaries are acceptable). On Windows, CreateFileMapping/MapViewOfFile
> has 64 bit support, but Python's mmap does not use it (the high offset
> DWORD is always zero). Only files smaller than 4 GB can be memory mapped.

With python 2.5.1 and numpy 1.0.3 under Fedora 7 x86_64, I just now
memmap'ed a 10 GB image cube without any trouble. I can't comment
about what will or won't work under Windows, but I've been doing > 4
GB files with linux ever since 64-bit support showed up in the early
betas of python 2.5 and numpy 1.0.

memmap'ing certainly isn't broken for me - removing it would be devastating.

Mike

-- 
mike.ressler@alum.mit.edu


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