[Numpy-discussion] numpy release
Stéfan van der Walt
stefan at sun.ac.za
Fri Apr 25 13:27:41 EDT 2008
2008/4/25 Anne Archibald <peridot.faceted at gmail.com>:
> > The agreement was:
Clearly that was only the agreement in my mind. I apologise if I
jumped the gun.
> > a) That x[0][0] should be equal to x[0,0] and
> > b) That x[0,:] should be equal to x[0] (as for ndarrays)
> >
> > This breaks as little functionality as possible, at the cost of one
> > (instead of two) API changes.
>
> Hold on. There has definitely been some confusion here. This is not
> what I thought I was suggesting, or what Alan thought he was
> suggesting. I do not think special-casing matrices for which one
> dimension happens to be one is a good idea at all, even temporarily.
> This is the kind of thing that drives users crazy.
Apparently, not having x[0][0] == x[0,0] drives them even crazier :)
I was trying to satisfy Alan's request without breaking the API in
more than one place. The whole idea of matrices was that you always
work with 2-dimensional arrays, even when you just extract a row.
Unless you have a proper hierarchical container (as illustrated in the
other patch I sent), returning a 1D array breaks at least some
expectation. If that's what the matrix users want, though, then we
should change it.
> My suggested stopgap fix was to make x[0] return a 1D *array*; I feel
> that this will result in less special-casing. In fact I wasn't aware
> that anyone had proposed the fix you implemented. Can we change the
> stopgap solution?
Yes, of course. NumPy is a community project, after all.
> > We should now discuss the proposals on the table, choose a good one,
> > and implement all the API changes necessary for 1.2 or 2. It's a pity
> > we have to change the API again, but the current situation is not
> > tenable.
>
> Yes, well, it really looks unlikely we will be able to agree on what
> the correct solution is before 1.1, so I would like to have something
> non-broken for that release.
Unless we agree on something, and soon, that won't happen. Your
workaround would break x[0] == x[0,:], so we're just swapping one set
of broken functionality for another.
I'm starting to see Chris Barker's point; allowing x[0] is causing
more problems than it is worth. On the other hand, how would you
index into a vector (as in
http://en.wikipedia.org/wiki/Vector_(spatial)) without it?
Regards
Stéfan
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