Hilbert-Spectrum in Matlab

I have yet another question. With the EMD I get a few intrinsic Modes. The
intrinsic Mode I get first have the highest frequencies and so on. Does
that also mean that the instanteanous frequencies at a specific time for
exampe t(1) are descending?

I try to illustrate it better:

I recieve 4 intrinsic modes from a signal s(t) and I define the
instanteanous frequency f for all the modes. 
When I pick now a special time for example t(1) should the frequencies from
IMF1 to IMF4 at this point descend? And when they dont do it what have I
done wrong?

I hope somebody understands me.

Best regards
Joanna

On Apr 28, 7:30&#4294967295;am, "joanna" <diadem_sierra@n_o_s_p_a_m.yahoo.de>
wrote:
> I have yet another question. With the EMD I get a few intrinsic Modes. The
> intrinsic Mode I get first have the highest frequencies and so on. Does
> that also mean that the instanteanous frequencies at a specific time for
> exampe t(1) are descending?
>
> I try to illustrate it better:
>
> I recieve 4 intrinsic modes from a signal s(t) and I define the
> instanteanous frequency f for all the modes.
> When I pick now a special time for example t(1) should the frequencies from
> IMF1 to IMF4 at this point descend? And when they dont do it what have I
> done wrong?
>
> I hope somebody understands me.
>
> Best regards
> Joanna

The purpose of intrinsic modes in EMD is to separate different time
scales in original signal in order to get well-behaved instantaneous
frequency for each mode.
You might not be doing it right
Test your program on some synthetic example, e.g. Rossler equation

BTW, why ask here on comp.dsp ?
You already know more about the subject than most regulars in this
group, especially VLV :-)

Kind regards