Re: PROBLEMS with transfer function calculated by the arx function

[Doug Stewart]

On Sun, Mar 24, 2019 at 10:09 AM Zeev Sherf <address@hidden> wrote:

Hi

When applying the following sequence of commands

xrun=xxx2((k-1)*nsamp+1:k*nsamp);

yrun=yyy2((k-1)*nsamp+1:k*nsamp);

what is xxx2 and yyy2   can you give us a working example so we can run it.

 

DAT = iddata (xrun',  xrun' , dt);

Did you really want xrun and xrun ??? or xrun and yrun?

 

 [SYS, X0] = arx (DAT, 'NA', NA, 'NB', NB);

  W=2*pi*frv;

 [MAG, PHA, W] = bode (SYS, W);

MAG vs frequency should be 1 at all frequencies and

PHA should be zero at all frequencies

It doesn't happen

Have you any explanation?

It is any other way to calculate the transfer function from SYS?

[num, den)=tfdata(sys)

 help @lti/tfdata

 

Thanks in advance

Zeev Sherf

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DAS