User`s guide

1 Quick Start
1-14
Time and Frequency Response
Thefollowingcommandsproducevarioustimeandfrequencyresponseplotsfor
LTI models (see “Time and Frequency Response” on page 5-9 for more
information).
step(sys) % step response
impulse(sys) % impulse response
initial(sys,x0) % undriven response to initial condition
lsim(sys,u,t,x0) % response to input u
bode(sys) % Bode plot
nyquist(sys) % Nyquist plot
nichols(sys) % Nichols plot
sigma(sys) % singular value plot
freqresp(sys,w) % complex frequency response
These commands work for both continuous- and discrete-time LTI models sys
without restriction on the number of inputs or outputs. For MIMO systems,
they produce an array of plots with one plot per I/O channel. For example,
sys = [tf(1,[1 1]) 1 ; tf([1 5],[1 1 10]) tf(–1,[1 0])];
bode(sys)