[Numpy-discussion] Checking for views

Dag Sverre Seljebotn d.s.seljebotn at astro.uio.no
Fri May 25 10:07:48 EDT 2012


On 05/25/2012 03:17 PM, Robert Kern wrote:
> On Thu, May 24, 2012 at 5:52 PM, Robert Kern<robert.kern at gmail.com>  wrote:
>
>> (Hmm, now that I think about it, the edge cases are when the strides
>> are 0 or negative. 0-stride axes can simply be removed, and I think we
>> should be able to work back to a first item and flip the sign on the
>> negative strides. The typical positive-stride solution can be found in
>> an open source C++ global array code, IIRC. Double-hmmm...)
>
> Except that it's still NP-complete.
>

Well, I guess N would be the number of dimensions, so that by itself 
doesn't tell us all that much. Question is if the worst case is no 
better than the trivial O(number of elements in the matrices), which 
would be bad.

Dag



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