Hi,

I try to make a bode plot of a Multi Input Multi Output (MIMO) system using the code below

m1=100; %[kg]

k1=1e5; %[N/m]

d1=100; %[Ns/m]

m2=1000;%[kg]

k2=1e4; %[N/m]

d2=1500;%[Ns/m]

A=[0 1 0 0; [-k1 -d1 k1 d1]/m1; 0 0 0 1; [k1 d1 -k1-k2 -d1-d2]/m2];

B=[0 0; -1/m1 0; 0 0; [-1 k2+d2]/m2];

C=[1 0 0 0; 0 0 1 0];

D=0;

sys=ss(A,B,C,D)

figure(10)

step(sys)

figure(11)

bode(sys)

then I receive the following message:

error: bode: require SISO systems

error: called from

frequency_responseat line 73 column 5

bode at line 66 column 24

indicating that I did not provide a SISO system. That’s correct, but is there a way to make a bode plot of a MIMO system?

# My system

- OS: Windows 11 Pro (version 21H2)
- Octave version: Version 6.4.0
- Installation method: Downloaded and installed “octave-6.4.0-w64-installer.exe” from Download