Computing summation in matlab

I have a matrix let say A=ones(144,40);
and I want to compute the summation with lower limit is 1 and upper limit is dimension of A like 144*40=5760.
How can I compute it using symsum or sum other function?

Answers (2)

Wayne King
Wayne King on 22 Feb 2013
Edited: Wayne King on 22 Feb 2013
A = ones(144,40);
B = sum(A(:));
or
B = sum(sum(A));
Mark Whirdy
Mark Whirdy on 22 Feb 2013
Edited: Mark Whirdy on 22 Feb 2013
If Wayne is right and you're talking about limits to the summation, is it that you want to control these limits as parameters, or you simply want to always sum over every element (1:(size(A,1)*size(A,2))) of the matrix?
Wayne provides the latter solution, a solution to the former might be
limitSum = @(X,l_b,u_b)(sum(X(l_b:u_b))); % define amonymous function
A = ones(144,40);
limitSum(A,1,size(A,1)*size(A,2)); % apply function to A

5 Comments

I think the OP is just referring to the limits of the summation as in
\sum_{n=1}^{N} x[n]
No...it mean when we compute summation this is a lower and upper limit
5760
like SUM(A).where is matrix of size 144x40.
1
Thanks...any help plz
where A is matrix of size 144x40
did you look at my answer? that sums all the elements in the matrix
then its just a sum as Wayne said

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on 22 Feb 2013

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