On Thu, 14 Jun 2001, Antoine Cazes wrote: > > Dear Rooters, > > I cannot fit an histogram with a Breit Wigner. I created a function with > two parameters ant fited the histogram: > > TF1 *bw = new TF1("bw","[0]/((x-[1])*(x-[1])+[0]/4)",0,1.4); > h->Fit("bw"); > > but the fit gives a line in the bottom of my plot and bad parameters. > > I also created a C++ function which initialize the TF1 object (like in > the manual with the Lorenzian+background example (pages 66-67) but I get > the same result. > > Then, I redefined the TF1 Object with 4 parameters: > > TF1 *bw = new TF1("bw","[0]/((x-[2])*(x-[3])+[1]/4)",0,1.4); > h->Fit("bw"); > > The fit look great in the screen, except that the parameters 0 and 1 or > 2 and 3 are totally different. > > I use Root 3.0 on a Linux machine (RedHat 6.2) > > Thanks for your help, > > Antoine Cazes > > ------------------------------------- > Thomas Jefferson National Laboratory \ > Office 71 trailer 16 \ Institution: University of > Phone: (757) 269 5551 \ South Carolina > fax : (757) 269 6273 \ > http://www.jlab.org/~cazes/G7/ \ > --------------------------;-) > > > >
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