permute matrix dimensions: getting trickier ...

Hi gurus,

i have a multidimensional matrix (M) and want to plot every combination of two of its dimensions in a mesh. Here is the solution we came up with for octave toguether with its community:

% generate matrix M
size=11;
for A=(1:size)
   for B=(1:size)
       for C=(1:size)
           for D=(1:size)
               for E=(1:size)
                   M(A, B, C, D, E) = A*B^2 - C*D^3 +10*E;
               end
           end
       end
   end
end

% plot all pair combinations of M dimensions
n = ndims(M);
for i = 1:n
 for j = (i+1):n
    figure( (i-1)*n + j );
    clf;
    mesh( 1:size , 1:size ,...
        permute( M,[i j (1:n)( (1:n)!=i & (1:n)!=j )] )(:,:,1,1,1) );
    xlabel('abcde'(i));
    ylabel('abcde'(j));
 end
end

The command permute does not work in this form on matlab. I could'nt find a way out. Could u help me?

thx...

Answer 1

[David Sanchez]

I am a bit confused by the explanation of what you want. Is it something like this?

% plot all pair combinations of M dimensions
n = ndims(M);
for i = 1:size
    for j =1:size
        for k=1:size
            figure();
            clf;
            [X,Y] = meshgrid(1:size);
            mesh(X, Y ,M(:,:,i,j,k));
        end
    end
end

Answer 2

[oxy]

hi david, that s not exactly what i want.

To make it clear, if my matrix M has 3 dimensions, each having size = 'size', then i need

for k=1:size, mesh(1:size, 1:size, M(:, :, k)), end
for k=1:size, mesh(1:size, 1:size, M(:, k, :)), end
for k=1:size, mesh(1:size, 1:size, M(k, :, :)), end

In fact i have more dimensions. Thus i want to make this looping over the dimensions automatic.

If you try the code below in octave u will see that it selects the dimensions 'a' and 'b' and properly sort all other dimensions after that. In this example i have n=6 dimensions

    a=2; b=4 % this means i wanna mesh-plot dimensions 2 and 4 of M
    n=6 % my matrix M has 6 dimensions in total
    [a b (1:n)( (1:n)!=a & (1:n)!=b )] % this is how we sort the matrix M
    % and this is how the permute cmd would look like.
    % we just did not create the matrix M on this post, but the cmd works
    permute(M,[a b (1:n)((1:n)!=a & (1:n)!=b )])(:,:,1,1,1) )

Thus i only need to for-loop over 'a' and 'b' with the permute command and i get all possible combinations between the dimenaions of M. See the way i did it in the first post.

I hope i made my aim clear now (°~°)