[Numpy-discussion] Emulate left outer join?

[josef.pktd at gmail.com]

On Tue, Feb 9, 2010 at 7:06 PM, Pierre GM <pgmdevlist at gmail.com> wrote:
> On Feb 9, 2010, at 6:52 PM, Robert Kern wrote:
>> On Tue, Feb 9, 2010 at 17:47, Ralf Gommers <ralf.gommers at googlemail.com> wrote:
>>>
>>>
>>> On Wed, Feb 10, 2010 at 6:02 AM, Robert Kern <robert.kern at gmail.com> wrote:
>>>>
>>>>
>>>> For some reason, numpy.lib.recfunctions isn't in the documentation
>>>> editor. I'm not sure why.
>>>>
>>> Because it's not in np.lib.__all__ .
>>
>> Then there needs to be a secondary way to add such modules.
>
> All,
> I started porting JDH's functions from mlab to numpy.lib because I thought it'd be nice to have them directly in the core of numpy, instead of spread out in another package. However, I wanted to get a lot of feedback before advertising them:

chicken and egg problem, without advertising very few users know they exist

> * Should we put matplotlib.mlab functions directly into numpy ? I do think so, even if I think we should make them a tad more generic and not tie them to recarrays (you can do the same thing with structured arrays without the overhead, albeit without the convenience of access-as-attributes).
> * If yes to the question above, how should we proceed ? John, you mind committing these functions to numpy.lib.rec_functions yourself ? If you can't, any volunteer (I can do it but it would fall low on my priority list).
> Once this is settle, then we could think about a way to present them in the reference and/or user manual (like I did for genfromtxt).
> Let me know what y'all think.
> P.

I think it's very helpful to have more helper functions and
documentation to work with structured arrays. I also think that for
newcomers the distinction in the documentation between recarrays and
arrays with structured dtypes is not very clear, and how to work with
structured arrays is not sufficiently documented.

Essentially I only learned about them because of an answer Pierre gave
once to me on the mailing list and I started to read the matplotlib
and numpy source to see how to work with them. It also seems that
structured arrays become the more recommended approach than recarrays
(e.g. discussion by tabular developers on the mailing list and their
switch to structured arrays).

So, I'm in favor of advertising them, and advertising them for
structured arrays and only secondary for recarrays.

I have no idea about a good name that would suggest structured instead of rec.

Josef


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