Re: Constraints to parameters in FindFit?
- To: mathgroup at smc.vnet.net
- Subject: [mg51245] Re: [mg51200] Constraints to parameters in FindFit?
- From: "Maxim A. Dubinnyi" <maxim at nmr.ru>
- Date: Sun, 10 Oct 2004 01:57:16 -0400 (EDT)
- References: <200410080654.CAA24958@smc.vnet.net>
- Sender: owner-wri-mathgroup at wolfram.com
Hi, If "Par" is always positive, write it as Par->Exp[TmpPar] and seek for "TmpPar" instead of Par. Use Par->-Exp[TmpPar] for negative parameters. :) Sincerelly, Maxim A. Dubinnyi Jill Foley wrote: >Hi All, > >I am using FindFit to fit a series of peaks to some data. I would like >to be able to constrain some of the parameters of my fit to correspond >to physical reality. For example, some peaks should have a negative >amplitude, others positive, where the amplitudes are the parameters >that Mathematica is finding in FindFit. The peaks are all very near >each other, so without any constraint, it is making the wrong ones >negative. I'd like to specify that a given parameter should always be >negative. I am already giving an initial guess of the proper sign, but >it doesn't fix the problem. > >Please advise - Thanks! > >Jill. > >
- References:
- Constraints to parameters in FindFit?
- From: Jill Foley <efoley@princeton.edu>
- Constraints to parameters in FindFit?