MATLAB: Looping for calculate parameter

Question

Hi MATLAB community,

I am trying create a structure to calculate a parameter,

For made this, I would to calculate de a(1)*F(:,1)+a(2)*F(:,2)+a3*F(:,3)……until a(i)*F(i), respectily until that total number of parameters ((i=number of factors), 4 in the case). I have a doubt if I use for or while for this structure.

Could you help me?

Thank you very much

Guilherme Lopes de Campos

correlation=corrcoef(X); % size X(324,19)
eigvalue = eig(correlation); 
factor = nnz(eigvalue>=1);% number of factor ( 4 in the case)
nonfactor = nnz(eigvalue<1);
sumeigvalue = sum(eigvalue);
eigvalue = eig(correlation);
[n,j] = size(eigvalue)
for i = 1:n       
    if  eigvalue(i)>=1;        
        a(i)= eigvalue(i);     %obtained the vector of a(i)
    end
end
a = sort(a,'descend')
for i=1:factor
    parameter = a(i)*F(:,i);   % F is a matrix (324,4) 
    
end

Guilherme

Answer 1

With a FOR loop:

S = 0;
for k = 1:numel(a)
    S = S + a(k) * F(:, k);
end

Or without a loop:

S = F(:, 1:numel(a)) * a(:);