Re: Re: FindFit & NIntegrate

*To*: mathgroup at smc.vnet.net*Subject*: [mg96183] Re: [mg96162] Re: FindFit & NIntegrate*From*: DrMajorBob <btreat1 at austin.rr.com>*Date*: Mon, 9 Feb 2009 05:31:03 -0500 (EST)*References*: <gmecbc$acc$1@smc.vnet.net> <gmguqa$2u0$1@smc.vnet.net>*Reply-to*: drmajorbob at longhorns.com

Amen. WRI knows that a thousand users a day stumble over this, and they've had ample time to prevent it somehow. Bobby On Sat, 07 Feb 2009 02:38:53 -0600, ADL <alberto.dilullo at tiscali.it> wrote: > 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? > > -- DrMajorBob at longhorns.com