nyquist plot from frequency response data

Hi all,

I have a complex vector containing the response of a particular system to frequencies, given in another vector. How do make a bode plot? If I use the nyquist() function, I get the following warning message.

The numerator or denominator of this transfer function has complex-valued coefficients.

Therefore, I'm really not sure if the plot is correct or not.

Thanks

Answer 1

[Star Strider]

See the documentation on Data Preparation (link) for the System Identification Toolbox.

[Aneesh Vasudev]

Thanks. used frd().

[Star Strider]

As always, my pleasure.

I was not certain what option would be best for your data.

I recently solved a similar problem in How can ı get transfer function (link). That code may save you some time if you want to do something similar.