# FeldmanCousins¶

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 [email protected]
This notebook tutorial was automatically generated with ROOTBOOK-izer from the macro found in the ROOT repository on Sunday, October 02, 2022 at 09:32 AM.

In [1]:
if (!gROOT->GetClass("TFeldmanCousins"))

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