how can i sum different variables?

I have to perform this calculation and I don't know the tau values so it is a simobolic calculation. How can I implement it? Thank you so much.

a=2 N=4 n=3

[Torsten]

Define a function with the tau-vector, a, n and N as inputs. Then all the operations can and should be done numerically.

Answer 1

[Milan Bansal]

Hi GIORGIA FRANZINO,

I understand you want to solve the given expression in symbolic form for the case when a = 2, N = 4 and n = 3.

For the particular case when a = 2, N = 4 and n = 3, the expression becomes:

The above expression can be resolved in symbolic form as shown in the code snippet below:

% Define the symbolic variables
syms  v1 v2 v3; % Define symbolic variables

% Create symbolic tau vector
tau = [v1 v2 v3];

% use nested for loops to calculate the expression
s = 0; % initialize sum

for i1 = 1:2
    s1 = 0;
    for i2 = 2:3
        s2 = 0;
        for i3 = 3:3
            p = tau(i1) * tau(i2) * tau(i3);
            s2 = s2 + p;
        end
        s1 = s1+s2;
    end
    s = s+s1;
end

% display results
disp(s)

Please refer to the following documentation link to learn more about "Symbolic Math Toolbox".

https://www.mathworks.com/help/symbolic/

Hope this helps!

[GIORGIA FRANZINO]

Thanks you so much