Re: parameters problem in FindFit

*To*: mathgroup at smc.vnet.net*Subject*: [mg92876] Re: parameters problem in FindFit*From*: annetts729 <davidannetts at aapt.net.au>*Date*: Thu, 16 Oct 2008 05:06:18 -0400 (EDT)*References*: <gd4dl4$bg2$1@smc.vnet.net>

Hi, Hi, > Hi, guys : > I get a list like this : > lis = {{12.5, 1.146}, {32, 1.145}, {50, > 1.144}, {69, 1.1424}, {84.6, > 1.139}} > My aim is : > FindFit[lis, > a - (b x^2)/(c + x), {{a, 1.14}, {b, 0.0003}, {c, 300}}, x] > As we can see, I want this list to be fitted using parameters a, b, c > around 1.14, 0.0003, 300. However Mathematica gives { b, 10^8} and {c, > 10^14} far from what I expect.I set "MaxIterations" to less times, > but it doesn' t make sense. > My friends didn't give the answer either, I am here for your advice. > Thanks in advance. Did you look at FindFit's Method option? Regards, Dave.