System Identification Toolbox not importing data properly

I am using the system identification toolbox to identify a transfer function using a bode plot. I have used it in the past without much errors

I'm currenlty using: import data --> frequency domain data --> frequency function (Amp/Phase)

The the amplitude that is imported seems to be backwards and scaled and the phase just seems to be scaled. I am not sure what is wrong, I have closed System Identification toolbox, restarted matlab, with no success

Update: The toolbox seems to take the absolute value of my amplitude plot and shift my phase to positive.

The following is the original data

The following is the imported data, it ooks very distorted and is clearly not what is in the original data.

Here are the settings I am using:

Answer 1

[Mathieu NOE]

hello

seems you are giving the amplitude in dB whereas the ID toolbox parameters is waiting for a linear scale amplitude

so you have to do first a dB to linear amplitude conversion

a_lin = 10.^(a_dB/20)

[fmo2641]

Thanks.