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?

Réponses (2)

Wayne King
Wayne King le 22 Fév 2013
Modifié(e) : Wayne King le 22 Fév 2013

0 votes

A = ones(144,40);
B = sum(A(:));
or
B = sum(sum(A));
Mark Whirdy
Mark Whirdy le 22 Fév 2013
Modifié(e) : Mark Whirdy le 22 Fév 2013

0 votes

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 commentaires

Wayne King
Wayne King le 22 Fév 2013
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
Algorithms Analyst
Algorithms Analyst le 22 Fév 2013
where A is matrix of size 144x40
Wayne King
Wayne King le 22 Fév 2013
did you look at my answer? that sums all the elements in the matrix
Mark Whirdy
Mark Whirdy le 22 Fév 2013
then its just a sum as Wayne said

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