Function or variable 'rscale' not recognised.

A = [ 0   1   0 
    980  0  -2.8 
    0   0  -100 ];
B = [ 0 
    0 
    100 ];
C = [ 1 0 0 ];
poles = eig(A)

poles = 3×1

31.3050 -31.3050 -100.0000

t = 0:0.01:2;
u = zeros(size(t));
x0 = [0.01 0 0];
sys = ss(A,B,C,0); 
[y,t,x] = lsim(sys,u,t,x0); 
plot(t,y) 
title('Open-Loop Response to Non-Zero Initial Condition') 
xlabel('Time (sec)') 
ylabel('Ball Position (m)')

p1 = -10 + 10i; 
p2 = -10 - 10i; 
p3 = -50; 
K = place(A,B,[p1 p2 p3]); 
sys_cl = ss(A-B*K,B,C,0); 
lsim(sys_cl,u,t,x0); 
xlabel('Time (sec)')
ylabel('Ball Position (m)') 

p1 = -20 + 20i; 
p2 = -20 - 20i; 
p3 = -100; 
K = place(A,B,[p1 p2 p3]); 
sys_cl = ss(A-B*K,B,C,0); 
lsim(sys_cl,u,t,x0); xlabel('Time (sec)') 
ylabel('Ball Position (m)')

t = 0:0.01:2; 
u = 0.001*ones(size(t)); 
sys_cl = ss(A-B*K,B,C,0); 
lsim(sys_cl,u,t); xlabel('Time (sec)') 
ylabel('Ball Position (m)')
axis([0 2 -4E-6 0])

Nbar = rscale(sys,K) 

Unrecognized function or variable 'rscale'.

Function or variable 'rscale' is not recognised by matlab. I get an error like this.

https://ctms.engin.umich.edu/CTMS/index.php?example=Introduction&section=ControlStateSpace

However, the url above has this code description. How can I use it?

Answer 1

[Rik]

As it says right on that page:

"Note that this function is not standard in MATLAB. You will need to download it here, rscale.m, and save it to your current workspace."