How can i form a 3d matrix from a 2d matrix

Hello I am struck in a problem for long time. I have got a 2D matrix of size 19x1339. I have another parameter pi=p*ch*win. Where p=1;ch=21;win=56. I wish to make a 3D matrix of dimension pi x 19 x 1339 without inserting zeros in the matrix. Can anyone please help me? It is really very urgent. I am doing the following: Here WCOH and WCS have the dimension 19 x 1339.

    pi=p*ch*win;
    xcoh(pi,:,:)=WCOH;%ADD coherence feature for each window here
    xcs(pi,:,:)=WCS;

[KL]

Your 2D matrix has 19x1339 elemets and you want to create a 3D matrix with 112x19x1339 elements without inserting zeros into it? What do you want to have in the 3D matrix then?

[Arijit Ghosh]

Actually I am running a loop of (number of patients*number of channel*number of windows), which is denoted by pi. This pi then have the value 1*21*56 which is equal to 1176. I wish to insert this 1176 into my 3D matrix.

[Jan]

The question is not clear. Where do you want to insert 1176? Please post a small example, with e.g. "pi=2" and "WCS=magic(2)".

Please do not use "pi" as name of the variable, because this shadows the builtin function pi, which replies teh value of Pi.

Answer 1

[Jan]

Perhaps you mean:

xcs = repmat(reshape(WCS, 1, 19, 1339), 1176, 1, 1);

But this 3D array would consist of 1176 identical slices and this redundancy would be really inefficient.