Re: matrix transformation

[Bertrand Roessli]

"reshape (permute (reshape (x, nr, nc, nb), [1, 3, 2]), nb*nr, nc)"

Amazing...

Thanks,

Bertrand


On Wed, 2009-05-27 at 13:54 -0400, John W. Eaton wrote:
> On 27-May-2009, James Sherman Jr. wrote:
> 
> | I thought that Paul meant that you could use A' instead of permute in
> | Jaroslav's suggestion.  Obviously, A' doesn't work by itself.
> | 
> | I've played around a bit with just reshape and permute, but I can't seem to
> | think of an elegant solution or any solution at all that uses just reshape
> | and permute.  The best solution that I can think of (assuming that the
> | initial matrix is always of the form [M,M, ..., M]) is just extracting M and
> | using rep mat, something like if M is an nxm matrix, and your initial matrix
> | is A:
> | 
> | M = A(1:n,1:m);
> | B = repmat(A, k, 1);
> | 
> | where k is the number of repetitions of M.
> 
>   x  = [ 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 ]
>   nr = rows (x)
>   nc = 3
>   nb = columns (x) / nc
>   reshape (permute (reshape (x, nr, nc, nb), [1, 3, 2]), nb*nr, nc)
> 
> jwe
> _______________________________________________
> Help-octave mailing list
> address@hidden
> https://www-old.cae.wisc.edu/mailman/listinfo/help-octave