PROBLEMS IN EVALUATING A TRANSFER FUNCTION THROUGH THE arx and bode algorithms

[Zeev Sherf]

Hi

 

When the following sequence of commands is applied to calculate a transfer function

 

DAT = iddata (xrun',xrun',dt);

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

  W=2*pi*frv;

[MAG, PHA, W] = bode (SYS, W);

 

MAG should be 1 for all the frequencies and PHA shall be zero for all frequencies

 

It doesn't happen

Can some one help?

 

Thanks in advance

 

Zeev