MATLAB Answers

Computing summation in matlab

4 views (last 30 days)
Algorithms Analyst
Algorithms Analyst on 22 Feb 2013
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
Mark Whirdy
Mark Whirdy on 22 Feb 2013
then its just a sum as Wayne said

Sign in to comment.

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!