lsim

Syntax

[Y, T, X] = lsim(SYS, U)

[Y, T, X] = lsim(SYS, U, T)

[Y, T, X] = lsim(SYS, U, T, X0)

Inputs

SYS

A state-space or transfer function model. The model must have at least as many poles as zeros.

U

The signal vector.

T

The time vector, which is assumed to contain constant intervals.

X0

The state vector initial conditions. Default = a zero vector.

Outputs

Y

The output response matrix.

Note: The outputs are stored by column.

T

The time vector.

X

The state trajectories matrix.

Note: The trajectories are stored by column.

Example

Plot state trajectories:

 A = [-20 -40 -60;1  0  0; 0  1  0];
B = [1;   0;   0];
C = [0   0   1];
D = 0;
T = [0:0.1:1];        % Time vector
U = zeros(size(T,1), size(T,2));    
X0 = [0.1 0.1 0.1];   % Initial Condition
sys = ss(A, B, C, D);    
[y, t, x] = lsim(sys, U, T, X0);
plot(t,x);
xlabel('Time (sec)');
ylabel('State Trajectory');
grid;