On Mon, Sep 8, 2014 at 12:10 PM, Jaime Fernández del Río < jaime.f...@gmail.com> wrote:
> On Mon, Sep 8, 2014 at 7:41 AM, Sturla Molden <sturla.mol...@gmail.com> > wrote: > >> Stefan Otte <stefan.o...@gmail.com> wrote: >> >> > stack([[a, b], [c, d]]) >> > >> > In my case `stack` replaced `hstack` and `vstack` almost completely. >> > >> > If you're interested in including it in numpy I created a pull request >> > [1]. I'm looking forward to getting some feedback! >> >> As far as I can see, it uses hstack and vstack. But that means a and b >> have >> to have the same number of rows, c and d must have the same rumber of >> rows, >> and hstack((a,b)) and hstack((c,d)) must have the same number of columns. >> >> Thus it requires a regularity like this: >> >> AAAABB >> AAAABB >> CCCDDD >> CCCDDD >> CCCDDD >> CCCDDD >> >> What if we just ignore this constraint, and only require the output to be >> rectangular? Now we have a 'tetris game': >> >> AAAABB >> AAAABB >> CCCCBB >> CCCCBB >> CCCCDD >> CCCCDD >> >> or >> >> AAAABB >> AAAABB >> CCCCBB >> CCCCBB >> CCCCBB >> CCCCBB >> >> This should be 'stackable', yes? Or perhaps we need another stacking >> function for this, say numpy.tetris? >> >> And while we're at it, what about higher dimensions? should there be an >> ndstack function too? >> > > This is starting to look like the second time in a row Stefan tries to > extend numpy with a simple convenience function, and he gets tricked into > implementing some sophisticated algorithm... > Maybe the third time is a gem. > > For his next PR I expect nothing less than an NP-complete problem. ;-) > How about cholesky or qr updating? I could use one right now. Josef > > >> Jaime > > -- > (\__/) > ( O.o) > ( > <) Este es Conejo. Copia a Conejo en tu firma y ayúdale en sus planes > de dominación mundial. > > _______________________________________________ > NumPy-Discussion mailing list > NumPy-Discussion@scipy.org > http://mail.scipy.org/mailman/listinfo/numpy-discussion > >
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