Derive & plot a step response of ss equation

trying to plot a step response using the y equation my lecturer provided, and here's my Script:

A=[0 0 -2;1 0 -5;0 1 -4]; %Inputs b=[1;0;0]; c=[9 -26 66]; d=0; [b,a]=ss2tf(A,b,c,d); %convert to transfer function [r,p,k]=residue(b,a); %extracting partial fractions t=0 %Initial Condition

for i=1:1:10 t=t+0.1 y=1+r(1)*exp(-t)+r(2)*t*exp(-t)+r(3)*exp(-2*t)

end;

Tried plotting it but the plot is blank? My Matlab skills aren't to great either. Thanks!

Answer 1

[Santhana Raj]

First of all, try to use the {}code button, when you write the code. It will be easier to understand and has more probability that you will get an answer.

The mistake is neither your t nor your y is a vector. You want it to be so, if you want o plot it. On every iteration, the value of y gets replaced!! so you have only one value of y at the end instead of 10.

y(i)=1+r(1)*exp(-t)+r(2)*t*exp(-t)+r(3)*exp(-2*t);

Try the above line within your for loop. I think it should work.