[Numpy-discussion] Extracting all the possible combinations of a grid

[Gary Ruben]

Gael Varoquaux wrote:
> On Fri, Sep 21, 2007 at 02:58:43PM -0600, Charles R Harris wrote:
>>    I found generators a good approach to this  sort of thing:
> 
>>    for (i,j,k) in triplets(n) :
> 
> That's what we where doing so far, but in the code itself. The result was
> unbearably slow.
> I think for our purposes we should build a precalculated table of these
> nuplets, and then do array calculations on them.

I'm not sure whether this helps, but I have found this generator-based 
recipe <http://aspn.activestate.com/ASPN/Cookbook/Python/Recipe/190465> 
very useful in the past. The comment "If you require the complete list 
of permutations, just use the built-in list() operator" may apply to 
your situation,

Gary R.