fitting multiple datasets

*To*: mathgroup at smc.vnet.net*Subject*: [mg57978] fitting multiple datasets*From*: Nate Traaseth <traaseth at chem.umn.edu>*Date*: Wed, 15 Jun 2005 05:58:11 -0400 (EDT)*Sender*: owner-wri-mathgroup at wolfram.com

I have two questions, 1) I have multiple datasets, and one function that depend on multiple parameters, of which I would like to find a global best fit to three of the parameters. However, within each dataset, I need to specify slightly different parameters within the function. For example (not actual function and will not make sense), f(a_,b_,c_,d_,e_) = a*x^5 + b*x^4 + c*x^3 + d*x^2 + e*x In datasets 1-5, I would like to specify different "a" and "b" values (for each dataset), while finding the best single fit (global) for "c," "d," and "e" in the function using all datasets. I see that using "FindFit" one can enter multiple points of the same dataset, and minimize the parameters of a function to best fit one dataset, but is it possible to enter multiple datasets and find a global minimum for multiple parameters in a function? Or do I need to write my own loop in Mathematica? 2) When I am doing a minimization using "FindFit" how do I tell the minimization routine that I am only interested in solutions (assuming they exist as local minima) that satisfy a certain range. For example, a solution to a parameter that is only within the range {a,b}. thanks Nate

**Follow-Ups**:**Re: fitting multiple datasets***From:*frank <frank@kuesterei.ch>