Re: Optimisation of FourierCoefficients
- To: mathgroup at smc.vnet.net
- Subject: [mg75244] Re: Optimisation of FourierCoefficients
- From: dh <dh at metrohm.ch>
- Date: Sat, 21 Apr 2007 23:16:25 -0400 (EDT)
- References: <f09gh3$12c$1@smc.vnet.net>
Hi Edmund,
The arguments of FindMinimum are evaluated before fed to FindMinimum. To
prevent this, declare a function that only takes numerical arguments, e.g.:
fun[y_/;NumericQ[y]]:=Abs[Fourier[{y,1}][[1]]];
FindMinimum[fun[y],{y,2}]
hope this helps, Daniel
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
>
>
>