non-linear fitting of data

*To*: mathgroup at yoda.physics.unc.edu*Subject*: non-linear fitting of data*From*: wilson%scuche.hepnet at lbl.gov*Date*: Fri, 29 May 92 09:59:36 PDT

Univ of South Carolina, 29-MAY-1992 The Fit function as described in the MMA book only does linear fitting, meaning that it fits only to a linear combination of user-supplied functions. I want to do nonlinear fitting, meaning that I want to give MMA a function of x and also a function of adjustable parameters, and have MMA find the best values for those parameters, not just some multiplicative factor for the function. Does anyone know how I can do that with Fit, or if there is a nice package I can use? I tried the following: Fit[ wire5k, {1/(c (1 + ((x-d)/c)^2))}, {x,c,d} ] The idea is that I want x,c and d to all vary. The red error msg I got was: Fit::arg: Fit has received {x, c, d} as argument. Scott