Re: matrix transformation

[John B. Thoo]

On May 27, 2009, at 9:40 AM, Paul Campbell wrote:


> On Wed, May 27, 2009 at 3:52 AM, Bertrand Roessli
> <address@hidden> wrote:
> > Hello,
> >
> > I would like to transform a matrix like
> > e.g.
> >
> >  1   2   3   1   2   3   1   2   3
> >  4   5   6   4   5   6   4   5   6
> >  7   8   9   7   8   9   7   8   9
> >
> > in
> >
> >  1 2 3
> >  4 5 6
> >  7 8 9
> >  1 2 3
> >  4 5 6
> >  7 8 9
> >  1 2 3
> >  4 5 6
> >  7 8 9
> >
> > Is there a simple way to do that?
> >
> > Thanks in advance
> >
> > Bertrand Roessli
>
> Found a simpler method
>
> A'
>
> http://wiki.aims.ac.za/mediawiki/index.php/Octave:Vectors_and_matrices

Hi.  I don't know how to accomplish Bertrand's request easily;  
however, I don't think A'  does it.

octave-3.0.5:32> M = [1, 2, 3; 4, 5, 6; 7, 8, 9];
octave-3.0.5:33> A = [M, M, M];  % Bertrand's original
octave-3.0.5:34> B = [M; M; M];  % what Bertrand wants
octave-3.0.5:35> B - A'
ans =

   0  -2  -4
   2   0  -2
   4   2   0
   0  -2  -4
   2   0  -2
   4   2   0
   0  -2  -4
   2   0  -2
   4   2   0

octave-3.0.5:36>

---John.