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Re: Optimisation of FourierCoefficients

• To: mathgroup at smc.vnet.net
• Subject: [mg75290] Re: Optimisation of FourierCoefficients
• From: "Edmund" <Edmund.koch at tu-dresden.de>
• Date: Tue, 24 Apr 2007 03:22:13 -0400 (EDT)
• References: <f09gh3$12c$1@smc.vnet.net> <f0f8mp$jl8$1@smc.vnet.net>

Thanks to all of you.

Solution from dh, Peter Pein and Jens-Peer work.

I have to learn more about the way Mathematica works.

Edmund


"Jens-Peer Kuska" <kuska at informatik.uni-leipzig.de> schrieb im Newsbeitrag 
news:f0f8mp$jl8$1 at smc.vnet.net...
> Hi,
>
> and
>
> obj[y_?NumericQ] := Abs[Fourier[{y, 1}][[1]]]
>
> FindMinimum[obj[y], {y, 2}]
>
> gives you an other  error message but the DFT
> is done correctly.
>
> Regards
>   Jens
>
> Edmund wrote:
>> I want to find the minimum of a Fourier-Coefficient as a function of the
>> input values.
>>
>> FindMinimum[Abs[Fourier[{ y, 1}][[1]]], {y, 2}]
>>
>> The actual problem is a little more complicated, but even this simple
>> statements gives the error messages I can't understand.
>>
>> Fourier::fftl: Argument {y, 1} is not a non-empty list or rectangular 
>> array
>> \
>> of numeric quantities.
>>
>>
>> Any suggestion ?
>>
>> best regards
>>
>> Edmund
>>
>>
>>
>