[Numpy-discussion] Short-hand array creation in `numpy.mat` style

[josef.pktd at gmail.com]

On Fri, Jul 18, 2014 at 4:21 PM, Charles G. Waldman <charles at crunch.io>
wrote:

> Joseph Martinot-Lagarde writes:
>
> > Compare what's comparable:
>
> That's fair.
>
> > In addition, you have to use AltGr on some keyboards to get the brackets
>
> Wow, it must be rather painful to do any real programming on such a
> keyboard!
>
>  - C
>
>
> On Fri, Jul 18, 2014 at 1:15 PM, Joseph Martinot-Lagarde
> <joseph.martinot-lagarde at m4x.org> wrote:
> > Le 18/07/2014 20:42, Charles G. Waldman a écrit :
> >> Well, if the goal is "shorthand", typing numpy.array(numpy.mat())
> >> won't please many users.
> >>
> >> But the more I think about it, the less I think Numpy should support
> >> this (non-Pythonic) input mode.  Too much molly-coddling of new users!
> >> When doing interactive work I usually just type:
> >>
> >>>>> np.array([[1,2,3],
> >> ...                   [4,5,6],
> >> ...                   [7,8,9]])
> >>
> >> which is (IMO) easier to read:  e.g. it's not totally obvious that
> >> "1,0,0;0,1,0;0,0,1" represents a 3x3 identity matrix, but
> >>
> >> [[1,0,0],
> >>    [0,1,0],
> >>    [0,0,1]]
> >>
> >> is pretty obvious.
> >>
> > Compare what's comparable:
> >
> > [[1,0,0],
> >   [0,1,0],
> >   [0,0,1]]
> >
> > vs
> >
> > "1 0 0;"
> > "0 1 0;"
> > "0 0 1"
> >
> > or
> >
> > """
> > 1 0 0;
> > 0 1 0;
> > 0 0 1
> > """
> >
> > [[1,0,0], [0,1,0], [0,0,1]]
> > vs
> > "1 0 0; 0 1 0; 0 0 1"
> >
> >> The difference in (non-whitespace) chars is 19 vs 25, so the
> >> "shorthand" doesn't seem to save that much.
> >
> > Well, it's easier to type "" (twice the same character) than [], and you
> > have no risk in swapping en opening and a closing bracket. In addition,
> > you have to use AltGr on some keyboards to get the brackets. It doesn't
> > boils down to a number of characters.
> >
> >>
> >> Just my €0.02,
>


It's the year of the notebook.

notebooks are reusable.
notebooks correctly align the brackets in the second and third line
and it looks pretty, just like a matrix


(But, I don't have to teach newbies, and often I even correct whitespace on
the commandline, because it looks ugly and I will eventually copy it to a
script file.)

Josef
no broken windows!
well, except for the ones I don't feel like fixing right now.






> >>
> >>     - C
> >>
> >>
> >>
> >>
> >> On Fri, Jul 18, 2014 at 10:05 AM, Alan G Isaac <alan.isaac at gmail.com>
> wrote:
> >>> On 7/18/2014 12:45 PM, Mark Miller wrote:
> >>>> If the true goal is to just allow quick entry of a 2d array, why not
> just advocate using
> >>>> a = numpy.array(numpy.mat("1 2 3; 4 5 6; 7 8 9"))
> >>>
> >>>
> >>> It's even simpler:
> >>> a = np.mat(' 1 2 3;4 5 6;7 8 9').A
> >>>
> >>> I'm not putting a dog in this race.  Still I would say that
> >>> the reason why such proposals miss the point is that
> >>> there are introductory settings where one would like
> >>> to explain as few complications as possible.  In
> >>> particular, one might prefer *not* to discuss the
> >>> existence of a matrix type.  As an additional downside,
> >>> this is only good for 2d, and there have been proposals
> >>> for the new array builder to handle other dimensions.
> >>>
> >>> fwiw,
> >>> Alan Isaac
> >>>
> >>> _______________________________________________
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> >>
> >
> >
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