How to do the Fourier Analysis in ferret

["Yogesh K. Tiwari" <Yogesh.Tiwari@xxxxxxxxxxxxxxx>]

Hello Ferret Users,

How to do the Harmonic Analysis inside the ferret.

I have ASCII data looks like :-

!Yr    co2_obs   co2_model

1993    355.10   360.23
1993    355.49   360.61
1993    355.87   360.89
1993    357.75   361.27
1993    358.20   362.12
1993    358.38   361.96
1993    357.48   361.46
......................
....................
.........
......

The data period is till 2002,


How to fit the co2 values to get the components of Fourier transform and 
then how to do the inverse fourier transform.

Finally I want to compute the residuals by  subtracting the original
co2 ( as above in table) from the values got from the inverse
transform.

First time I am trying to use the ferret in this type of statistical 
analysis, so please help me in bit detail, if possible.

Thanks in advane for your help.

Regards,
Yogesh

--

=================================================================
Yogesh K. Tiwari,
Max-Planck Institute for Biogeochemistry,
Hans-Knöll-Strasse 10, D-07745 Jena,          Postal Address:
GERMANY                                       Postfach 10 01 64
                                              D-07701 Jena,
Office   : +49 3641 576376 (direct)           GERMANY
Fax      : +49 3641 577300
Home     : +49 3641 235748
Mobile   : +49 1736988789
e-mail: yogesh.tiwari@bgc-jena.mpg.de
          __0                __0
         -\<,               -\<,
        (_)/(_)            (-)/(_)
=================================================================