Subscript no. 1 is out of range. Error when using tf command?

I am trying to compute a transfer function from a state space I calculated using the reg() function. Here is the code:

%% Setup clear;clc;close all a = [-0.0558 0.9968 0.0802 0.0415; 0.598 0.115 0.0318 0; -3.05 0.388 0.465 0; 0 0.0805 1 0]; b = [0.00729; -0.475; 0.153; 0]; c = [0 0 0 1]; d = [0]; sys = ss(a,b,c,d) Aircraft = tf(sys) nRA = [10]; dRA = [1 10]; Rudder_Actuator = tf(nRA,dRA) nWF = (1/3)*[1 0]; dWF = (1/3)*[3 1]; Washout_Filter = tf(nWF,dWF)

num = (Rudder_Actuator*Aircraft*Washout_Filter); den = (1+(Washout_Filter*Rudder_Actuator*Aircraft)); tf = minreal(tf(num,den)); Transfer_Funk = tf % insert epic bass Nummys = [0.3825 -0.664 4.46 0]; % numerator coefficients of Transfer_Funk Dennys = [1 9.809 -2.426 -4.835 3.526 1.27 -0.07644]; % denominator coefficients [A1,B1,C1,D1] = tf2ss(Nummys,Dennys); sys1 = ss(A1,B1,C1,D1) %% 1) p_feed = [-0.0051 -0.468 -0.279+0.628i -0.279-0.628i -1.106 -9.89]; Feed_Gain = place(A1,B1,p_feed) Fixed_Feed_Gain = transpose(Feed_Gain); %% 2) p_Control = [-0.0253 -2.34 -1.39+3.14i -1.39-3.14i -5.53 -49.5]; Observe_Gain = place(A1,B1,p_Control) Fixed_Observe_Gain = transpose(Observe_Gain); %% 3) Compensator_Sys = reg(sys1,Feed_Gain,Fixed_Observe_Gain) A2 = [-60.18 -575.3 -2451 -6587 -7728 -191.1; 1 0 -9.731 16.89 -113.5 0; 0 1 -9.356 16.24 -109.1 0; 0 0 -1.687 4.665 -31.33 0; 0 0 -0.4593 1.797 -5.355 0; 0 0 -0.03395 0.05894 0.6041 0]; B2 = [2.218;25.44;24.46;7.025;1.201;0.08877]; C2 = [-50.37 -577.7 -2455 -6585 -771 -191.2]; D2 = [0]; % These values come from the Compensator_Sys state matricies

disp('The transfer function of the compensator is') [Nummers,Denners]=ss2tf(A2,B2,C2,D2); Gc = tf(Nummers,Denners)

Everything works until I try to create the transfer function from the state space. It says: Error using InputOutputModel/subsref (line 44) Subscript no. 1 is out of range. Error in MEM355 (line 48) Gc = tf(Nummers,Denners)

Any ideas how I can fix this?

Answer 1

[Juan Gomez]

make sure that you have all of your equation in rule, i had the same problem because i didn't put a (*) for multiply 2 arguments

Answer 2

[Image Analyst]

Make sure Nummers doesn't exceed the max value for the first dimension. What does this say

whos tf
whos Nummers