How to sum up multiple vectors, element by element, to recieve one final value?

Asked by Oliver Cowburn

Oliver Cowburn (view profile)

on 29 May 2019
Latest activity Edited by James Tursa

James Tursa (view profile)

on 29 May 2019
Accepted Answer by Kevin Phung

Kevin Phung (view profile)

I am a beginner to MATLAB and I'm probably trying to run before I can walk here, however, I need to calculate this equation below and I have found no explanations online: Where, WP and Op are vectors with 8760 iterations each.
I want to conduct this equation for each iteration of h (i.e. WP(1)*Op(1)/Op(1)) and summate each value to find a single value for the whole calculation (Ex).
I've been down the for loop route but not fully understanding how I can link it to my problem.
Any help would be amazing. Thanks!

Release

R2018b

Answer by Kevin Phung

Kevin Phung (view profile)

on 29 May 2019
Edited by Kevin Phung

Kevin Phung (view profile)

on 29 May 2019

example:
W = [1 2 3 4 5];
O = [1 2 3 4 5];
%do the numerator first:
E = W.*O; %element wise product
%sum up the products, and divide by the sum of all elements in O:
E = sum(E)/sum(O); % E should now be a scalar -- your answer
let me know if this helps.

Answer by James Tursa

James Tursa (view profile)

on 29 May 2019
Edited by James Tursa

James Tursa (view profile)

on 29 May 2019

The numerator is just a simple dot product between two vectors, and the denominator is just a simple sum. Using the fact that a dot product between two vectors can be accomplished with the matrix multiply operator, you can just do a (row vector) * (column vector) operation on top and a sum on the bottom. E.g.,
If both are row vectors, then
E = WP * Op.' / sum(Op);
If both are column vectors, then
E = WP.' * Op / sum(Op);
Note that the .' operation is a non-conjugate transpose.