Re: fit a complex function
- To: mathgroup at smc.vnet.net
- Subject: [mg98975] Re: fit a complex function
- From: dh <dh at metrohm.com>
- Date: Thu, 23 Apr 2009 06:41:34 -0400 (EDT)
- References: <gsmn0k$d2r$1@smc.vnet.net>
Hi,
you can not directly fit a complex function. But you may defined an
error function of the parameters, that returns a real number, specifying
the error. If you then search the minimum of this function over the
parameters, you have solved your problem.
here is a simplified version with 1 dim. where we fit Exp[I a x]:
====================================
d = Table[{x, Exp[2 I x]}, {x, 0, Pi, Pi/10}];
err[a_] := Total[Abs[ d[[All, 2]] - ( Exp[a I #] & /@ d[[All, 1]])]^2];
FindMinimum[err[a], a]
====================================
Daniel
Magician wrote:
> I have data in the following form
>
> xi , Fi (xi is real but Fi is complex)
>
> i want to determine a fit by using function
>
> F(x, a , b,c, d)= a Exp(- x^2/b) + c Sin( d x)
>
> a, b, c and d are complex numbers to be determined so as to accurately
> represent the data.
>
> How to do this problem?
>
>