adding matrices inside cell array

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Franco
Franco on 10 Feb 2011
how does one add all of the matrices stores in a cell array?
  1 Comment
Oleg Komarov
Oleg Komarov on 10 Feb 2011
Be more specific, what do you intend by add the matrices? (take the sum of each single matrix, sum elementwise all the matrixes, all the single matrix sums are added together?

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Accepted Answer

vish
vish on 10 Feb 2011
a={[1,2;3,4],[1,2;3,4];[1,2;3,4],[1,2;3,4]}
a{1}+a{2}+a{3}+a{4}
If there are many elements, use two for loops and run all the positions one by one using the equation c=a{i,j} + a{i+1,j+1}.

More Answers (1)

Oleg Komarov
Oleg Komarov on 10 Feb 2011
An example:
% Create dummy input
c = {[1 2; 3 4], [3 3; 1 1]}
c =
[2x2 double] [2x2 double]
% Elementwise sum across matrices (only if ALL matrices have same size)
sum(cat(3,c{:}),3)
ans =
4 5
4 5
% Total sum of each matrix
cellfun(@(x)sum(x(:)),c,'un',0)
ans =
[10] [8]
% Grand sum
c = cellfun(@(x) x(:),c,'un',0);
sum(cat(1,c{:}))
ans =
18
Oleg
  1 Comment
Mariacarla Memeo
Mariacarla Memeo on 30 Sep 2011
Excuse me Oleg,
can you explain your solution for the first case(sum of each element of matrices), because I have to sum 72 matrices [25x25] placed in a cell array [72x1] and I've no idea to how set your solution in my example. Please.

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