Solution for architecure dependence in Numeric ?

[Michael Spencer]

"Johannes Nix|Johannes.Nix"@uni-oldenburg.de wrote:
> Hi,
> 
> I have a tricky problem with Numeric. Some time ago, I have generated
> a huge and complex data structure, and stored it using the cPickle
> module. Now I want to evaluate it quickly again on a workstation
> cluster with 64-Bit Opteron CPUs - I have no more than three days to
> do this. Compiling Python and running Numeric has been no problem at
> all. However, I get an error message when accessing the data pickled
> before. (I can load it regularly on 32 bit computers, but it is a
> quite complex data object, so I really don't want to store every
> element as ASCII data).  The problem seems to be with 64 Bit integers
> (with 32-bit-floats, no problem was observed).
> 
> This looks like that (from the Unix command shell):
> 
> 
> jnix at 32bithost:~> python ~/python/test_npickle.py  -dump test.pck
> jnix at 32bithost:~> python ~/python/test_npickle.py  test.pck
> [0 1 2 3 4 5 6 7 8 9]
> jnix at 32bithost:~> ssh 64bithost python ~/python/test_npickle.py  test.pck
> Traceback (most recent call last):
>   File "/home/jnix/python/test_npickle.py", line 16, in ?
>     a = cPickle.load(file(filename))
>   File "/home/jnix/lib/python2.4/SuSE-9.0/x86_64/Numeric/Numeric.py", line 520, in array_constructor
>     x.shape = shape
> ValueError: ('total size of new array must be unchanged', <function array_constructor at 0x2a960b0b18>, ((10,), 'l', '\x00\x00\x00\x00\x01\x00\x00\x00\x02\x00\x00\x00\x03\x00\x00\x00\x04\x00\x00\x00\x05\x00\x00\x00\x06\x00\x00\x00\x07\x00\x00\x00\x08\x00\x00\x00\t\x00\x00\x00', 1))
> 
> 
> also I get:
> jnix at 32bithost:~> python -c "import Numeric; print Numeric.arange(0).itemsize()"
> 4
> jnix at 64bithost:~>  python -c "import Numeric; print Numeric.arange(0).itemsize()"
> 8
> 
> 
> The script used to produce the example above is:
> 
> -------------------------------------------------------------------------
> #/usr/bin/python
> # -*- coding: latin1 -*-
> 
> import Numeric
> import cPickle
> import sys
> 
> if len(sys.argv) > 1 and sys.argv[1] == '-dump':
>     filename = sys.argv[2]
>     binary=1
>     a = Numeric.arange(10) 
>     cPickle.dump(a, file(filename,'w',binary))
> 
> else:
>     filename = sys.argv[1]
>     a = cPickle.load(file(filename))
>     print a
>     
> 
> ---------------------------------------------------------------------
> 
> 
> So what would you suggest ? Can I hack Numeric to assume non-native
> 32 bit integer numbers ?
> 
> Many thanks for any help,
> 
> Johannes
It might be worth posting to the Numeric mailing list, mirrored at 
http://news.gmane.org/gmane.comp.python.numeric.general