Re: FindFit & NIntegrate

*To*: mathgroup at smc.vnet.net*Subject*: [mg96162] Re: FindFit & NIntegrate*From*: ADL <alberto.dilullo at tiscali.it>*Date*: Sat, 7 Feb 2009 03:52:43 -0500 (EST)*References*: <gmecbc$acc$1@smc.vnet.net> <gmguqa$2u0$1@smc.vnet.net>

Dear Jens-Peer, if a questions appears over and over ("10^6 times before") it should mean something to thinking people! Latins used to say, "Errare humanum est, perseverare diabolicum". Does this mean anything to Mathematica developers? Do you mean that it is impossible to find a sensible way to do something that 10^6 people would do differently? ADL On 6 Feb, 10:10, Jens-Peer Kuska <ku... at informatik.uni-leipzig.de> wrote: > Hi, > > and > > model[x_?NumericQ,a_?NumericQ,b_?NumericQ,c_?NumericQ]:= > NIntegrate[function[x_,t_,a_,b_,c_],{t,0,inf}]; > > will work. We had this 10^6 times before. > > Regards > Jens > > > > hmalissa wrote: > > I want to use the FindFit function (or similar) to fit some > > experimental data: > > > fit=FindFit[data,expr,pars,vars] > > > Usually this works very well, but in this particular case the model > > expr consists of a NIntegrate over another function, like: > > > model[x_,a_,b_,c_]:=NIntegrate[function[x_,t_,a_,b_,c_],{t,0,inf}]; > > fit=FindFit[data,model[x,a,b,c],{a,b,c},x] > > > FindFit now complains about non-numerical values; of course that makes > > sense. > > How can I force FindFit to do the fitting anyway?