Implementing summation in Matlab using Matlab Function

I intend to implement the summation function. θ and are outputs from other simulink blocks whereas assume different values for each (i,j) combination starting from (0,0) to (4,4). I believe this can be done with use of Matalb Function block but I'm not really able to find a similar example. Can some please suggest how can this done?

Answer 1

[David Hill]

I assume alpha is a 4x4 matrix, theta is a 1x4 array and lambda is a 1x4 array.

[theta,lambda]=meshgrid(theta,lambda);
output=sum(alpha.*theta.*lambda,'all');

[Abhishek Tiwari]

Thank you David for your quick response. alpha is a 5x5 matrix (just to avoid any confusion please consider the range of i and j each from 1 to 5), and theta & lambda are the outputs of the other blocks in the simulation file. I don't really have the them in the form of an array.