Im trying to construct delay vectors basically my code should be in the following form :

X(t) = [x(t), x(t-1),x(t-2),...........,x(t-(D-1))] of dimension D

where d is my own choice accordingly.

I have updated my code and it is as follows:

d = 500;
x = zeros(d,1);
t = 1:1000
x = [x(t): x(t -(d-1))]

I have tried my best to come up with the code but still having problems..I need help!!! Thank you