# [SciPy-user] Mathematica Element-wise Multiplication

Johann Cohen-Tanugi cohen@slac.stanford....
Mon Dec 17 01:49:38 CST 2007

```Matthieu Brucher wrote:
>
>
> 2007/12/17, Johann Cohen-Tanugi <cohen@slac.stanford.edu
> <mailto:cohen@slac.stanford.edu>>:
>
>     thanks for these precisions, David. Reading it, I still come to think
>     that it is a potential source of confusion to let a "row array" have a
>     transpose or T method, that essentially does nothing.
>
>
>
> In object oriented code, this can happen often, but it is not a
> problem. It does what you want : inverse the axis, even if there is
> only one axis.
hmmm...... okay... What I wanted was to transpose a 1D array into a
vector, or vice-versa, with the linear algebra behavior in mind. I
understand that numpy does not follow this, but I cannot believe that
this behavior *is* what everybody wants! Tom's initial email was
symptomatic, and Stefan's response, with the proposal to use the T
method even more so!

Assuming that this natural linear algebra could be retrieved when, and
*only* when, the array is 1D, I do not see how such an implementation
could break codes that depend on it, because I don't see why someone
would call 'a.T' just to have 'a' again.... But it is probably my lack
of imagination.
Anyway, enough of this. I am sure the developers know better than me...

cheers,
Johann

>
>
>     I guess there is a
>     reason behind this situation, but given the fact that it is there,
>     I am
>     wondering whether T or transpose of a row array could in fact return
>     what it is expected to, aka the 2d column array. Is there any
>     reason not
>     to have this functionality?
>
>
>
> More code in a simple function (thus slower) ? Breaking some code that
> depend on it ? Not doing what the documentation says ?
> I think the method should not be changed, it does exactly what it says
> it does. Changing its behaviour because of Matlab is not a good
> solution, Python is not Matlab.
>
> Matthieu
> --
> French PhD student
> Website : http://matthieu-brucher.developpez.com/
> Blogs : http://matt.eifelle.com <http://matt.eifelle.com> and
> http://blog.developpez.com/?blog=92