How to trim time series?

X = rand(1,128)-0.5;

fs = 1000;

Ts = 1/fs;

Y = lowpass(X,100,fs);

plot(Y);

Z = conv(X,Y);

THE length of Z is 255

I want to trim the ends off Z so that it has a length of 128.

What do I have to do?

Answer 1

[Ravi Narasimhan]

Are you trying to discard elements 129 through 255?

If so,

Z(129:end) = []; % Discard the unwanted elements
or
Z=Z(1:128); % Keep the desired elements

should do it.