How is modeled the more short time this loop?

Hi everybody, i have the for loop, but loop time is very long. How can i make the more short time?

R=rand(1,3000);

W=zeros(1,length(R));

for i=1:length(R)+1

for ii=1:length(R)-i+1

W(i)=W(i)+R(ii)*R(ii+i-1)

end

end

Answer 1

[DGM]

I bet this can be simplified further, but here.

l = 4;
R = rand(1,l);

W = zeros(1,l);
for k = 1:l
	W(k) = sum(R(1:l-k+1) .* R(k:end));
end

EDIT: Updated to match question change. Also, echoing to console takes a considerable amount of time.

[Erkan]

Thank you so much, i will examine and write the answer

[Erkan]

Hi DGM, firstly i have mistaked while writing the question;

it must be W(i)=W(i)+R(ii)*R(ii+i-1). For this state i excuse me. if it possible, can you examine again?

[DGM]

Edited.

[Erkan]

Yes, it is right working, thank you so much.