Summation issue using loop

I am trying to implement this summation in matlab but i do not know how ?

thank u

[Robert U]

What have you tried so far?

Answer 1

[Ali aaa]

since n is just a number -1

for n=0:n-1

x(n+1) = ((x^2)(mN+i)

end

Answer 2

[Robert U]

Hi Ali aaa,

in your code parts are missing. Without knowing any constraints about the variables, I suggest the following solution:

1. Define a (local) function to solve the summation formula
2. check input validity
3. Try to vectorize the calculation

function [Em] = sum_mNi(x,m,N)

    validateattributes(x,{'numeric'},{'vector','nonempty'});
    validateattributes(m,{'numeric'},{'scalar','nonempty'});
    validateattributes(N,{'numeric'},{'scalar','nonempty'});
    
    Em = 1/N * sum(cell2mat(arrayfun(@(ind) x.^2 .* (m*N + ind),0:N-1,'UniformOutput',false)'),1);

end

The solution might be wrong, depending on the input value types.

Kind regards,

Robert