Re: [Numpy-discussion] The NumPy Fortran-ordering quiz

[Charles R H. <cha...@gm...>]

On 10/17/06, Travis Oliphant <oli...@ie...> wrote:
>
> Charles R Harris wrote:
> >
> >
> > On 10/17/06, *Lisandro Dalcin* <da...@gm...
> > <mailto:da...@gm...>> wrote:
> >
> >     I was surprised by this
> >
> >     In [14]: array([[1,2,3],[4,5,6]]).reshape((3,2),order='F')
> >     Out[14]:
> >     array([[1, 5],
> >            [4, 3],
> >            [2, 6]])
> >
> >
> > This one still looks wrong.
>
> Why does this look wrong.  What do you want it to be?  Perhaps you are
> thinking about the input array as C-order and the output array as
> Fortran order.   That's not what reshape does.   The order argument
> specifies how you think about both the input and output.
>
> Thus, reshape does the equivalent of a Fortran ravel to [1,4,2,5,3,6]
> and then a Fortran-order based fill of an empty (3,2) array:  giving you
> the result.


Why a Fortran ravel? I am thinking of it as preserving the memory layout,
just messing with how it is addressed.

Chuck