MathGroup Archive 2001

[Date Index] [Thread Index] [Author Index]

Search the Archive

Fitting of complex values

  • To: mathgroup at
  • Subject: [mg31741] Fitting of complex values
  • From: Ioan Alexandre Romoscanu <romoscanu at>
  • Date: Thu, 29 Nov 2001 00:14:27 -0500 (EST)
  • Organization: Swiss Federal Institute of Technology (ETHZ)
  • Sender: owner-wri-mathgroup at

Hi all

I have a question about nonlinear fdata fitting with Mathematica.

If one looks for parameters of a (real) function, with x as variable
and, say, {a,b} as parameter, one efficiently uses (from the help file)

NonlinearFit[data, FitFunction[x,a,b], x, {a,b}]

This works fine, but it requires the data and the FitFunction to be
*real* values.

Is there any way to fit a set of complex data with a complex
FitFunction, like, say,

FitFunction=(a x+ i b x)/a

The algorithm implemented in NonlinearFit[ ] does not accept this. There
should be a way though, for complex values are still values (especially
in Mathematica, which nicely deals with complex number in general)

Please excuse me if I miss an important point.

Thanks in advance (and please, if you have a hint, please send it to me
per email too)

ioan alexandre romoscanu          - institut für mechanik
CLA G31, eth zentrum,              8092 zürich, schweiz
tel. +41 1 632 77 54,                    +41 76 323 63 05
fax.+41 1 632 11 45,  romoscanu at
nestlé research center
H 212
1000 lausanne 26
tel.  +41 21 785 83 65             fax. +41 21 785 85 53

  • Prev by Date: EPS Export, Wrong characters
  • Next by Date: Very difficult axes inversion?? How to???
  • Previous by thread: EPS Export, Wrong characters
  • Next by thread: Very difficult axes inversion?? How to???