[Date Index] [Thread Index] [Author Index]
Re: Constraints to parameters in FindFit?
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. > >