FeldmanCousins.C File Reference

Detailed Description

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

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Processing /mnt/vdb/lsf/workspace/root-makedoc-v608/rootspi/rdoc/src/v6-08-00-patches/tutorials/math/FeldmanCousins.C...
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

void FeldmanCousins()
{
   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.
   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;
}

Author

Adrian John Bevan bevan.nosp@m.@SLA.nosp@m.C.Sta.nosp@m.nfor.nosp@m.d.EDU

Definition in file FeldmanCousins.C.