Problem with ploting bode funcion of higher order

I have tried to plot a simple bode function of 3rd order and higher:

clear all;

clc;

close all;

s=tf('s');

w=1/(s*(s+1)^2)

bode(w)

but, didnt get any plot

instead I get the error after running the program :

w =

1

---------------

s^3 + 2 s^2 + s

Continuous-time transfer function.

output =

0×1 empty double column vector

output =

-Inf

50

50

Error using conv (line 28)

A and B must be vectors.

Error in freqgrid>LocalAddPhaseExtrema (line 357)

lhs2 = psum(conv(d1,d1),[conv(d2,d2) 0]);

Error in freqgrid (line 138)

w = LocalAddPhaseExtrema(w,z{1},p{1});

Error in ltipack.ltidata/freqresp (line 45)

w = freqgrid(z,p,Ts,Grade,Focus);

Error in resppack.ltisource/magphaseresp (line 36)

[mag,phase,w,FocusInfo] = freqresp(SysData(ct),grade,wspec,true);

Error in wavepack.waveform/draw (line 25)

feval(this.DataFcn{:});

Error in wrfc.plot/draw (line 17)

draw(wf)

Error in wrfc.plot/init_listeners>LocalRefreshPlot (line 79)

draw(this)

Warning: Error occurred while evaluating listener callback.

> In DynamicSystem/bodeplot (line 142)

In DynamicSystem/bode (line 94)

In bode1 (line 6)

>>

******by the way, the same bode function in different computer works perfectly.

Please anyone can Help me?

thank you,

Hezi

Answer 1

[Star Strider]

Yours is the second instance of this I have seen recently (the first being The inbuilt code "bode " is not working).

That was solved by uninstalling and rinstalling MATLAB and the Toolboxes. Since that is a bit extreme, if you would like a second opinion first, Contact Support.

Meanwhile, the posted code works in the online Run feature —

s=tf('s');
w=1/(s*(s+1)^2)

w =
 
         1
  ---------------
  s^3 + 2 s^2 + s
 
Continuous-time transfer function.

bode(w)

.