Re: Bounding Parameters used in FindFit[]

*To*: mathgroup at smc.vnet.net*Subject*: [mg75242] Re: Bounding Parameters used in FindFit[]*From*: Bill Rowe <readnewsciv at sbcglobal.net>*Date*: Sat, 21 Apr 2007 23:15:24 -0400 (EDT)

On 4/20/07 at 12:30 AM, jlaforge at gmail.com (Joshua LaForge) wrote: >Is there a method to limit (bound) the search for a least-squares >fit with FindFit[] in Mathematica 5.2? >For example I am using FindFit[] to fit a decaying exponential of >the form P1 * Exp[-t/P2] + P3. I know from the experiment that P3 >is smaller than the value Mathematica continues to find for that >parameter. It would be great if there was a way to bound the search >for P3 to help Mathematica properly optimize P1 and P2. Once you require an additional constraint such as P3<P1 && P3<P2 you no longer have a least squares problem and cannot use =46indFit. You will need to create a function that computes the sum of squares and use NMinimize on it. NMimimize performs a constrained optimization. -- To reply via email subtract one hundred and four