Hi All, I have been using minuit to fit multiple Gaussians. My code is becoming more elegant now and I don't want to keep using global variables so I dug in TMinuit.cxx and found this at the beggining: //*-* - The functions SetObjFit(TObject *obj) and GetObjFit() can be * //*-* used inside the FCN function to set/get a referenced object * //*-* instead of using global variables. * I have no clue as what to do to actually make use of this. I found the definition (?) of this function in G__Minuit.cxx but that only made me more confuse. I guess first of all the my object containing the data to be fit needs to be transformed to a TObject and then I can use SetObjectFit (note there is no SetObjFit - I am saying this not to be picky just to point out a little inconsistency between the comment and the code) within FCN to have access to my object. However, how do I get this object inside FCN? I must confess there is a couple arguments in the FCN function whose meaning I never quite understood: void fcn(Int_t &npar, Double_t *gin, Double_t &f, Double_t *par, Int_t iflag) { // computes Chi^2 // &npar = number os parameters // *gin = ???????? , not used here // &f = returns the chisq^2 value in this variable // *par = the array of parameters // iflag = ???????? , not used here so far I have survived without messing with them... But neither one is of type TObject, therefore I gather they are not what I am after. If anyone has some example code showing the use of SetObjectFit (hopefully showing the creation of the TObject as well) I would appreciate it. thanks, have you all a nice day, Antonio Antônio Kanaan Departamento de Física - Universidade Federal de Santa Catarina CP 476 -- CEP 88040-900 -- Florianópolis -- SC -- Brasil http://www.astro.ufsc.br/~kanaan e-mail: kanaan@astro.ufsc.br Phone: 55,48,3319069 FAX : 55,48,3319946
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