# Sum of an arrays elements

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Rasmus on 23 Feb 2014
Commented: Rasmus on 23 Feb 2014
I have an assigntment which sounds like this:
square each element in C and determine the sum of all C's elements
How do i do this? I don't get the right result, that i am supposed to get.

Mischa Kim on 23 Feb 2014
Edited: Mischa Kim on 23 Feb 2014
I'd assume
C = [1 2 3];
res = sum(C.^2)
What is the input, what is the expected result?
Mischa Kim on 23 Feb 2014
A = [10 12 15; 7 9 13];
B = A';
C = ones(4,10);
C(2,5) = 8;
C(:,7) = zeros(4,1);
C(1:2,1:3) = A;
C(2:4,8:9) = B;
C(3,:) = [];
sum(sum(C.^2))
ans =
1391
Rasmus on 23 Feb 2014
Hmm weird, that was pretty much what i was doing, but at least now i get the same result.
Thnak you :)

Sagar Damle on 23 Feb 2014
Rasmus,entered matrix is wrong again! I get this fact from your description. Your matrix is - C =
10 12 15 1 1 1 0 1 1 1
7 9 13 1 8 1 0 10 7 1
1 1 1 1 1 1 0 15 13 1
Any way,I think this is what you want :
A = C.^2; Ans = sum(A(:));
For understanding purpose,see effect of A(:).
Note : For 2-dimentional matrix A, sum(sum(A)) is same as sum(A(:)).