Thanks Agustinus Oey for this very useful code. It works greatly with my expectations.
Also, thanks Gabriele for bringing up the non-dimensional natural frequency, that was helpful as well.

Very useful piece of code.
What I think is missing is the output of natural frequencies for the various modes in dimensional form.
According to the original reference, it seems to me that, if the line 349:
tmp=num2str(sqrt(tmp/I2I6)*handles.a^2,'%1.2f');
is subsituted by the following line:
tmp=num2str(sqrt(tmp/I2I6)*handles.a^2*sqrt(handles.B/handles.ps)/handles.a^2/2/pi,'%1.2f');
which is equivalent to
tmp=num2str(sqrt(tmp/I2I6)*sqrt(handles.B/handles.ps)/2/pi,'%1.2f');
then output frequencies are dimensional (in Hz).
It would therefore be very useful to have both outputs in the lower left listbox, i.e. nondimensional frequency and also dimensional (Hz or rad/s) frequency.
Bye,
Gabriele