lsim: Remove input signal from plot

I am using the function lsim to plot a system response. How can I remove the input signal from the plot so that it only shows the response?

Answer 1

[Robert U]

Hi cricketking13,

if you don't want to have lsim plot the default plot, just "collect" the output and plot as you desire:

%% LPF
order        = 3;
ripple       = 1; %pass band ripple
f_c          = 22e6;
[num1, den1] = cheby1(order, ripple, 2*pi*1.10*f_c, 'low', 's');

%% Create input signal
Fs       = 200e6;
Ts       = 1/Fs;
NFFT     = 2^12;
Runtime  = (NFFT-1)*Ts;
t        = 0:Ts:Runtime;
a_in     = 1;
fin      = 5e6;
phase_in = 0;
y_in     = a_in * sin( 2 * pi * fin * t + phase_in );  % 4096 points

%% filter signal
% create system
myFilter = tf(num1,den1);
% apply filter to time domain signal
[y_out, time] = lsim(myFilter,y_in,t);
% plot without y_in
plot(time,y_out')

Kind regards,

Robert

[rearyia]

Thank you!