Repeated application of lsim()

Hello,

I am using lsim to calculate the response to an input noise signal in a column vector. My model is a simple first-order continuous time SISO filter. This works fine for a single trial of the input.

Now I want to repeat this for say 100 random trials. I usually do this by creating a matrix for my input signal with each column representing a trial. But this does not seem to work with lsim().

Here is the basic code that works for Ntrials=1.

num = 1; den = [1 1]; sys = tf(num, den);

dt = 0.1; t = (0:dt:10).';

Ni = length(t); % Number of time samples

Ntrials = 1; % Number of trials.

x = randn(Ni, Ntrials); % input signal y = lsim(sys, x, t); % output signal

plot(t,y)

In general is there a simple way to vectorize a simulation like this? Say I do everything with column vectors as above and then when I want to switch to looking at repeated trials. Is there a way to get matlab to just go off and adds columns for each trial (without me rewriting a lot of code)?

Thanks