Fitting Exponential Function

Roofit and RooStats
1

Dear All

Could anybody please suggest me how to fit some distribution with some exponential function in root.
Thanks
Shikshit

2

Hi,

root [0] TH1F* h = new TH1F("h", "hist", 110, -1., 10)
root [1] TF1* fillfunc = new TF1("fillfunc", "TMath::Exp((x - 3.)/10.2)")
root [2] h->FillRandom("fillfunc")
root [3] h->Draw()

Now we have a filled histogram. Let’s fit it with an exp() with a few parameters:

root [4] TF1* fitfunc = new TF1("fitfunc", "TMath::Exp((x-[0])/[1])")
root [5] fitfunc->SetParameter(0, 0.);
root [6] fitfunc->SetParameter(1, 1.);
root [7] h->Fit(fitfunc)

Cheers, Axel.