how do I supply an rcdb.root file to chanser

[dglazier]

Sorry if I am missing something absolutely glaring in the documentation, please point me to it if i am, but how do I supply an rcdb.root file to chanser in order to read the beam energy from it?

[dglazier]

Sorry documentation is a work in progress, hopefully get onto it this week.
To set the clas12root databases you use the same syntax as for clas12root e.g. :

clas12databases::SetCCDBLocalConnection("/home/dglazier/clas12root/RunRoot/ccdb.sqlite");
clas12databases::SetRCDBRootConnection("/home/dglazier/clas12root/RunRoot/rcdb.root");

These lines must be added to Run***.C or Processor.C type files

[dglazier]

Now if you want to set the beam energy you can get this from the RunInfo object which is set from rcdb. So in you final state class header file you can implement a DerivedChangeRun function which sets the energy of your beam 4-vector

void DerivedChangeRun() final {
     auto ebeam=GetRunInfo()->_BeamEnergy;
     auto mele = 0.00051099891;
     std::cout<<"Change beam energy to :"<<ebeam<<std::endl;
     _beam.SetXYZT(0,0,ebeam,TMath::Sqrt(ebeam*ebeam + mele*mele));
   }

This will also work for simulated data assuming your Lund input file records the electron beam energy in the expected slot. If not you can edit this function with any hack you want.