[ROOT] Help with TMinuit

From: Bardelli Luigi (bardelli@fi.infn.it)
Date: Tue Nov 06 2001 - 11:22:10 MET

Next message: Rene Brun: "Re: [ROOT] Help with TMinuit"
Previous message: Thomas Bretz: "Re: [ROOT] Class not in dictionary (strange behaviour of TChain?)"
In reply to: Rene Brun: "[ROOT] Please send me your best pictures, macros, histograms,etc"
Next in thread: Rene Brun: "Re: [ROOT] Help with TMinuit"
Reply: Rene Brun: "Re: [ROOT] Help with TMinuit"
Messages sorted by: [ date ] [ thread ] [ subject ] [ author ]

I'm trying a multidimensional fit using the TMinuit class with my custom
FCN to be minimized: after some documentation, these are the questions
left:

- What is the exact meaning of the void MyFunc(Int_t &npar, Double_t *gin,
Double_t &f, Double_t *u, Int_t flag)  arguments of the custom
function (set by SetFCN) ? 
Moverover which is the input and which the output of MyFunc ?

- Defining a parameter: the TMinuit::DefineParameter method allows to set
a parameter with limits; how can I set one parameter without?

Asking for an advice: 
Having a function with many parameters, and no analytical derivative,
which is the best approach to fit the data? Is it correct to use the
"raw" TMinuit ?

(I'm using ROOT Version 3.00/02)

Thanks for any help

Luigi




-------------------------------
 Luigi Bardelli                
 INFN Sezione di Firenze       
 E-Mail: bardelli@fi.infn.it   
-------------------------------

Next message: Rene Brun: "Re: [ROOT] Help with TMinuit"
Previous message: Thomas Bretz: "Re: [ROOT] Class not in dictionary (strange behaviour of TChain?)"
In reply to: Rene Brun: "[ROOT] Please send me your best pictures, macros, histograms,etc"
Next in thread: Rene Brun: "Re: [ROOT] Help with TMinuit"
Reply: Rene Brun: "Re: [ROOT] Help with TMinuit"
Messages sorted by: [ date ] [ thread ] [ subject ] [ author ]

This archive was generated by hypermail 2b29 : Tue Jan 01 2002 - 17:51:06 MET