The inbuilt code "bode " is not working in my matlab.

When I try to enter a simple program like

 N=[100 2e3 1e4]; D=[1e-6 1e-4 1 0 0]; bode(N,D)

It shows an error as below.

Error using freqfocus
Too many input arguments.

Error in ltipack.ltidata/freqresp (line 75)
   FocusInfo = freqfocus(Grade,w,mag.*exp(1i*ph),z,p,Ts,linDelay,[]);

Error in resppack.ltisource/magphaseresp (line 34)
         [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)

Can anyone help me to resolve this?

Thank you

[Walter Roberson]

What shows up if you use

which -all freqfocus

On my system it shows up as being part of controllib

[Brindha chellaiah]

it show me this "C:\Program Files\MATLAB\R2016a\toolbox\control\control\freqfocus.m

C:\Program Files\MATLAB\R2016a\toolbox\shared\controllib\engine\freqfocus.m % Shadowed"

Its is because I copied Freqfocus in toolbox\control directory. Previously No freqfocus file was there. And as you say it is a part of controllib. Should I update anything?

[Walter Roberson]

That first one does not exist for me, only the second. You should check to see what is in it.

[Brindha chellaiah]

Yeah. The first one exist cox I pasted it on my own :-) .Ok. Thanks a lot. I will check the program. Is that the only source for problem? or any installation error?

[Brindha chellaiah]

Sorry @Roberson, I am not able to find the defect in the code. Can you please help me in checking this code. Is the code running for you?

Thanks a lot for your help

[Massimo Zanetti]

I run your line of code

N=[100 2e3 1e4]; D=[1e-6 1e-4 1 0 0]; bode(N,D)

on my Matlab R2015b, and it worked. See Attachment.

[Brindha chellaiah]

@Zanetti: Thanks for the response. Still Its is not working in my system and shows the same error as I mentioned above. Any program related to bode plot is not running properly.

Any Idea what might be the error? Can I take it as an installation error?

[Massimo Zanetti]

I think it is an installation error. Try run the code on another installation. What is your Matlab version?

[Steven Lord]

Remove the copy of freqfocus.m that you pasted into the toolbox/control/control directory.

[Brindha chellaiah]

@zanetti: Mine is version R2016b.

@steven: I reinstalled too. and removed the copy of freqfocus.m from control/control directory.

Even now it show the same error but not "too many input arguments" Instead "Error using freqfocus (line 38) Simulink model 'damp' was called with incorrect number of arguments"

[Walter Roberson]

Could you confirm that you are getting that message about damp even when you are doing just

   N=[100 2e3 1e4]; D=[1e-6 1e-4 1 0 0]; bode(N,D)

?

Please post the entire error message, everything in red.

[Brindha chellaiah]

Yes Walter, Following is the error message

Error using freqfocus (line 38)
Simulink model 'damp' was called with incorrect number of arguments

Error in ltipack.ltidata/freqresp (line 74)
FocusInfo = freqfocus(Focus,Grade,w,mag.*exp(1i*ph),z,p,Ts,linDelay,[]);

Error in resppack.ltisource/magphaseresp (line 34)
         [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 137)
  In DynamicSystem/bode (line 93)
  In bode (line 129)_
|

Answer 1

[Walter Roberson]

In some situations, Simulink models in your path can have priority over .m files of the same name. See https://www.mathworks.com/help/matlab/matlab_prog/function-precedence-order.html :

8. Loaded Simulink® models
9. Functions in the current folder
10. Functions elsewhere on the path, in order of appearance

So from that part alone, we can see that if you have a loaded model named "damp" then it is going to take priority over functions in the current folder or functions elsewhere on the path.

When it comes to looking in any one folder, we see:

3. Simulink model files that are not loaded, with file types in this order:
a) SLX file
b) MDL file

7. Program file with a .m extension

We see from this that in any one directory damp.slx and damp.mdl would have priority over damp.m . But we also see from this is that when you are searching along the MATLAB path, if a damp.slx or damp.mdl is encountered and no damp.m has been encountered yet (because it is further along the path), then the damp.slx or damp.mdl will be used

If you have a loaded model named "damp", then there is not much that can be done except to rename the model.

If you do not have a loaded model named "damp", then what you need to do is use

which damp

which will tell you which directory it is finding the damp.slx or damp.mdl in. Then use pathtool to remove that directory from your MATLAB path or ensure that it is further along the path than toolbox/shared/controllib/engine/ is , If the damp.slx or damp.mdl is in your current directory, change directories or move it or rename it.

[Brindha chellaiah]

@walter: Thanks a lot for your detailed answer. this one solved my problem. My error is I had a loaded model named damp.slx