Re: Fourier transform

[Mark Lytle <mlytle0 sbcglobal net>]

I now have both the FFT and the interpolation function working, yes, it was because I hadn't activated all of 
the plug-ins, that was the trick.

Thank you Frédéric and Jean
--------------------------------------------
On Fri, 2/8/19, Frederic Parrenin <frederic parrenin univ-grenoble-alpes fr> wrote:

 Subject: Re: Fourier transform
 To: "Jean Brefort" <jean brefort free fr>, "Mark Lytle" <mlytle0 sbcglobal net>, gnumeric-list gnome org
 Date: Friday, February 8, 2019, 11:14 AM
 
 Hi Jean,
 
 Do you know if there has been work on the
 periodogram function after 
 Franck's
 work?
 I tried the function several times but
 I never manage to get sensible 
 results.
 
 All the best,
 
 Frédéric
 
 Le 08/02/2019 à 17:27, Jean Brefort a
 écrit :
> Hello,
>
> The Fourier function
 takes three arguments, but only one is needed. The
> first argument is a row or column of data
 to be transformed, the second
> is a
 boolean to select the transform type, direct or inverse, and
 the
> third is another boolean to select
 to separate real and imaginary parts
> of
 the result (the default is no separation).
> The function returns
 an array of one column of complex numbers or two
> columns of real numbers. Each column has a
 number of data equal to the
> power of 2
 just above the number of input data (the fft algorithm
 needs
> 2^n data, so if you give,
 let's say 100 numbers, 28 0s will be
> appended).
>
> As for all array functions, you need to
 select the output area, type
> the
 function and its arguments, and validate using
 Ctrl+Shift+Enter?
>
 Hope this helps,
> Jean
>
> Le vendredi 08
 février 2019 à 14:19 +0000, Mark Lytle a écrit :
> > Hello,
> >
> > Would like to use the Time Series
 features of Gnumeric, but the
> >
 online manual doesn't really show syntax.  I did a
 search on the
> > Gnumeric list looking
 for an example in use, but all I see are
> > esoteric discussions, no examples.
> >
> > Is there
 another reference with examples of even one of the time
> > series features in use? If I could see
 one, I could figure out the
> >
 rest.
> >
 Thanks,
> > Mark Lytle
 _______________________________________________
> > gnumeric-list mailing list
> > gnumeric-list gnome org
> > https://mail.gnome.org/mailman/listinfo/gnumeric-list
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