Sum up elements in cells

I want to sum up elements in cells so that a product of the sum is a matrix. The cell is for instance A{i,j}, with each cell contains a matrix B(p,q).

Now I want to matrix C which is a sum of each matrix in the cell A, so:

B_A{i,j} means matrix B(p,q) from cell A{i,j}

B_A{1,1} + B_A{1,2} + ... + B_A{1,j}
B_A{2,1} + B_A{2,2} + ... + B_A{2,j}
...
B_A{i,1} + B_A{i,2} + ... + B_A{i,j}*

and then sum again all the columns, so that matrix C has also dimension of pxq.

I am trying something like this:

C = A{i,:} + A{:,i} + A{j,:} + A{:,j};

However matrix dimensions is exceeded?

[Adam]

It would help if you could give a simple example, I'm not sure I follow from your description.

Answer 1

[Jan]

Perhaps you mean this:

S = 0;
for k = 1:numel(A)
  S = S + A{k};
end

Alternatively (faster processing, more temporary RAM required):

C = cat(3, A{:});
S = sum(C, 3);

[cniv_we]

That is exactly what I need. Thank you.