Fourier transform

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Fourier transform

Mark Lytle
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
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Re: Fourier transform

Jean Brefort
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
> [hidden email]
> https://mail.gnome.org/mailman/listinfo/gnumeric-list

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Re: Fourier transform

Frédéric Parrenin
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
>> [hidden email]
>> https://mail.gnome.org/mailman/listinfo/gnumeric-list
> _______________________________________________
> gnumeric-list mailing list
> [hidden email]
> https://mail.gnome.org/mailman/listinfo/gnumeric-list
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Re: Fourier transform

Jean Brefort
Hi Frédéric,

Not that I know.

Cheers,
Jean

Le vendredi 08 février 2019 à 18:14 +0100, Frederic Parrenin a écrit :

> 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
> > > [hidden email]
> > > https://mail.gnome.org/mailman/listinfo/gnumeric-list
> > _______________________________________________
> > gnumeric-list mailing list
> > [hidden email]
> > https://mail.gnome.org/mailman/listinfo/gnumeric-list

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Re: Fourier transform

Mark Lytle
In reply to this post by Mark Lytle
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 <[hidden email]> wrote:

 Subject: Re: Fourier transform
 To: "Jean Brefort" <[hidden email]>, "Mark Lytle" <[hidden email]>, [hidden email]
 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
 >> [hidden email]
 >> https://mail.gnome.org/mailman/listinfo/gnumeric-list
 >
 _______________________________________________
 > gnumeric-list mailing list
 > [hidden email]
 > https://mail.gnome.org/mailman/listinfo/gnumeric-list
 
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