Question

I am plotting a system in matlab using the command lsim(sys,u,t,x0) and trying to define my input signal as u(t)^(-2t). My question is how do I define this input signal in matlab. The matlab guides show that you use u=gensig() but beyond that I cannot understand how to define my input signal in u=gensig().

Answer 1

CODE:

clc
close all

% here gensig() is for standard signals
% like sin square and pulse

t = 0:0.001:5;
% define input
u = (1*(t>=0)).^(-2*t);

% deifne system
sys =2/(s+3);
% initial condition
xo = 2;
% output
y = lsim(sys,u,t,xo);
plot(t,y)
hold on
plot(t,u)
ylim([0 1.2])
legend('y(t)','x(t)')
grid on

RESULT: