Python/Numeric users be aware!

Benyang Tang benyang22 at gmail.com
Wed Oct 29 20:46:22 CET 2008


I also found that the a[5:] problem is Python version dependent.

On a 64-bit linux, of the following combinations I have tried, only
the first one has the problem. The other two are ok.
* Python 2.5.1 and Numeric 24.2
* Python 2.4.5 and Numeric 24.2
* Python 2.3.7 and Numeric 24.2

On Oct 29, 10:53 am, Benyang <benyan... at gmail.com> wrote:
> Maybe it has been reported somewhere, but it is a big surprise to me.
>
> # Try the following:
> import Numeric
> a = Numeric.ones(10)
> a[5:] = -1
> print a
>
> It works correctly on 32-bit linux machines and on 32-bit Windows XP:
> [ 1  1  1  1  1 -1 -1 -1 -1 -1]
>
> It is totally screwed up on 64-bit linux machines:
> [1 1 1 1 1 1 1 1 1 1]
>
> # The following works correctly on both 32-bit and 64-bit machines
> (notice the comma):
> a[5:,] *= -1
>
> The Python version is 2.5.1, and Numeric is the latest version 24.2.




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