Use a matrix instead of a for loop

I'm trying to condense my code. I currently have this for loop in my code

N = 100
x = 1:N

p = 6;
sum_x = zeros([p+1,1]);
for k=0:p
    sum_x(k+1) = dot(x(1:N-k),x(1+k:N));
end

This gives me the output I want, a matrix containing the sum of each dot product for k = 0:p.

I want to condense it using matrices in a way like this:

k = 0:p
sum_x = dot(x(1:N-k),x(1+k:N));

However MATLAB takes k's first value and ignores the rest, giving me a scalar output.

I've been playing around with the code for a while now and can't seem to get the solution I want this way. Please answer if you know how to get it.

Answer 1

[JESUS DAVID ARIZA ROYETH]

solution:

N = 100;
x = 1:N;
p = 6;
xx=repmat(x,p+1,1);
sum_x=diag(fliplr(triu(fliplr(xx)))*rot90(triu(fliplr(xx+(0:p)'))));