Feldman Cousins

Example macro of using the TFeldmanCousins class in root.

get a FeldmanCousins calculation object with the default limits of calculating a 90% CL with the minimum signal value scanned = 0.0 and the maximum signal value scanned of 50.0

Author: Adrian John Bevan bevan@SLAC.Stanford.EDU
This notebook tutorial was automatically generated with ROOTBOOK-izer (Beta) from the macro found in the ROOT repository on Thursday, January 19, 2017 at 04:32 PM.



In [1]:

    
if (!gROOT->GetClass("TFeldmanCousins")) gSystem->Load("libPhysics");

TFeldmanCousins f;

Calculate either the upper or lower limit for 10 observed events with an estimated background of 3. The calculation of either upper or lower limit will return that limit and fill data members with both the upper and lower limit for you.



In [2]:

    
Double_t Nobserved   = 10.0;
Double_t Nbackground = 3.0;

Double_t ul = f.CalculateUpperLimit(Nobserved, Nbackground);
Double_t ll = f.GetLowerLimit();

cout << "For " <<  Nobserved << " data observed with and estimated background"<<endl;
cout << "of " << Nbackground << " candidates, the Feldman-Cousins method of "<<endl;
cout << "calculating confidence limits gives:"<<endl;
cout << "\tUpper Limit = " <<  ul << endl;
cout << "\tLower Limit = " <<  ll << endl;
cout << "at the 90% CL"<< endl;









    



For 10 data observed with and estimated background
of 3 candidates, the Feldman-Cousins method of 
calculating confidence limits gives:
	Upper Limit = 13.505
	Lower Limit = 2.635
at the 90% CL