Time domain Vector problem

hi ,

i wish to preform the follwing :

m(t)=a(0)*p(t)+a(1)*p(t-T)+a(2)*p(t-2T)+...

where :

a(n)=[1 -1 1 -1 ] %randomize -1 or 1
p(t)=[1.2 ....] %Raised cosine filter with 1X8001 
T=1e-3;

how can I time shift p(t) ?

[Azzi Abdelmalek]

What is the values of t? What are the values of p for t<0?

[Roger Wohlwend]

I see several problems. (1) You cannot define a vector a(n) = [1 -1 1 -1]. Wrong sytax. Instead write a = [1 -1 1 -1]. (2) The same is true for vector p. Write p = [...] and not p(t) = [...]. (3) If you want a certain element of a vector, your index must be an non-negative integer. If you want the first element of vector a, you have to write a(1) and NOT a(0) as you did in the first line of code. (4) p(t-2T) is wrong syntax. Correct is: p(t-2*T)

Concering your question: What do you mean with time shifting p? You already do it in your first equation.