SVAC Event Filter

The SVAC event filter can be used to filter out events from a digi/mc/recon root file either using cuts on variables from the Merit or SVAC ntuples or using an event list.  The new and reduced digi/mc/recon root file can then, for example, be used with Fred for visualization.

Using the event filter with cuts on Merit or SVAC ntuple variables:

• Start root:
  • root[0] .x /nfs/slac/g/svac/common/builds/Fred/EventFilter/loader.C
  • root[1] TCut myCuts="CalTwrGap>300.0&&GltTower==8.0" // Define all your cuts here
  • root[2] .x /nfs/slac/g/svac/common/builds/Fred/EventFilter/evtFilter.C("Ntuple.root", "digi.root", myCuts, "output.root")
    • 'Ntuple.root' is either the Merit or SVAC ntuple you're looking at.
    • 'digi.root' is the input digi, recon or mc root file.
    • 'myCuts' are your cuts.
    • 'output.root' is the name of the output digi/recon/mc root file.
  • Note that you can only filter one file at the time (digi, recon or mc root). To get all of them, you have to run the filter three times.

   

Using the event filter with an already made event list using Event ID (Merit ntuple variable 'EvtEventId' or SVAC ntuple variable 'EventID'):

• If you need to make cuts on your own variables i.e. not standard SVAC or Merit variables, a different solution exists.
• First make the event list:
  • Make a list of Event IDs.
  • The event list file is just a simple text file containg one Event ID per line.
• Start root:  
  • root[0] .x /nfs/slac/g/svac/common/builds/Fred/EventFilter/loader.C
    • .x  /nfs/slac/g/svac/common/builds/Fred/EventFilter/evtFilterEventID.C("events.dat","digi.root","output.root")  
    • 'events.dat' is the list of Event IDs
    • 'digi.root' is the input digi,recon or mc root file.
    • 'output.root' is the name of the output digi/mc root file.
  • Note that you can only filter one file at the time (digi, recon or mc root). To get all of them, you have to run the filter three times.
  • NB! Currently this filter is incredibly slow and I suggest you use the event index filter instead!

   

Using the event filter with an already made event list using event indices:

• If you need to make cuts on your own variables i.e. not standard SVAC or Merit variables, a different solution exists.
• First make the event list:
  • Make a list of event indices using for example the Root macro '/nfs/slac/g/svac/common/builds/Root/Example_output2file/Output.C'
  • The event list file is just a simple text file containg one index per line. 'Index' here means the order in which the event appears in the run. It is not the Event ID!
  • Note that the index starts counting from 0.
• Start root:  
  • root[0] .x /nfs/slac/g/svac/common/builds/Fred/EventFilter/loader.C
    • .x  /nfs/slac/g/svac/common/builds/Fred/EventFilter/evtFilterEvtList.C("events.dat","digi.root","output.root")  
    • 'events.dat' is the list of event indices
    • 'digi.root' is the input digi,recon or mc root file.
    • 'output.root' is the name of the output digi/mc root file.
  • Note that you can only filter one file at the time (digi, recon or mc root). To get all of them, you have to run the filter three times.

You can now use the reduced digi/recon/mc root files in Fred and look at the filtered events. Please note that the abovementioned problem with MC variables in Merit being zero does not affect the MC information in FRED.

 

SVAC Ntuple Pruners

Use the ntuple pruners with cuts on either Merit or SVAC ntuple variables to reduce the size of your ntuples. Keep only the events you are interested in! To look at the pruned Root files you sometimes have to quit Root and start it up again. I'm sure it's a feature ..... 

 

Prune a single ntuple with cuts using variables from the same Ntuple:

• Start root:
  • root[0] .x /nfs/slac/g/svac/common/builds/Fred/EventFilter/loaderLight.C
  • root[1] TCut myCuts="CalTwrGap>300.0&&GltTower==8.0" // Define all your cuts here
  • root[2] .x /nfs/slac/g/svac/common/builds/Fred/EventFilter/evtPrunerSingle.C("Ntuple.root",  myCuts, "output.root")
    • 'Ntuple.root' is either the Merit or SVAC ntuple you're looking at.
    • 'myCuts' are your cuts.
    • 'output.root' is the name of the output Merit/SVAC root file.
  • Note that you can only filter one file at the time (Merit or SVAC).

 

Prune a single TChain of ntuples with cuts using variables from the same TChain:

• Start root:
  • root[0] .x /nfs/slac/g/svac/common/builds/Fred/EventFilter/loaderLight.C
  • root[1] TCut myCuts="CalTwrGap>300.0&&GltTower==8.0" // Define all your cuts here
  • root[2] TChain merit("MeritTuple") // You have to have the correct Tree name, either 'MeritTuple' for Merit or 'Output' for SVAC.
  • root[3] merit.Add("meritNtuple-1.root")
  • root[4] merit.Add("meritNtuple-2.root")
  • root[5] .x /nfs/slac/g/svac/common/builds/Fred/EventFilter/evtPrunerTChainSingle.C(&merit,  myCuts, "output.root")
    • '&merit' is either the Merit or SVAC TChain you're looking at.
    • 'myCuts' are your cuts.
    • 'output.root' is the name of the output Merit/SVAC root file.
  • Note that you can only filter one file at the time (Merit or SVAC).

 

Pruning a single ntuple with cuts using variables from a different Ntuple:

• Start root:
  • root[0] .x /nfs/slac/g/svac/common/builds/Fred/EventFilter/loaderLight.C
  • root[1] TCut myCuts="CalTwrGap>300.0&&GltTower==8.0" // Define all your cuts here
  • root[2] .x /nfs/slac/g/svac/common/builds/Fred/EventFilter/evtPrunerMultiple.C("CutNtuple.root", "FilterNtuple.root",  myCuts, "output.root")
    • 'CutNtuple.root' is either the Merit or SVAC ntuple you want to make a cut on.
    • 'FilterNtuple.root' is either the Merit or SVAC ntuple you want to filter
    • 'myCuts' are your cuts.
    • 'output.root' is the name of the output Merit/SVAC root file.
  • Note that you can only filter one file at the time (Merit or SVAC). If you want to prune both SVAC and Merit you have to run it twice.
  • Note that all four combinations of SVAC and Merit are valid.

   

Pruning a TChain with cuts using variables from a different TChain:

• Start root:
  • root[0] .x /nfs/slac/g/svac/common/builds/Fred/EventFilter/loaderLight.C
  • root[1] TCut myCuts="CalTwrGap>300.0&&GltTower==8.0" // Define all your cuts here
  • root[2] TChain merit("MeritTuple") // You have to have the correct Tree name, either 'MeritTuple' for Merit or 'Output' for SVAC.
  • root[3] merit.Add("meritNtuple-1.root")
  • root[4] merit.Add("meritNtuple-2.root")
  • root[5] TChain svac("Output") // You have to have the correct Tree name, either 'MeritTuple' for Merit or 'Output' for SVAC.
  • root[6] svac.Add("svacNtuple-1.root")
  • root[7] svac.Add("svacNtuple-2.root")
  • root[8] .x /nfs/slac/g/svac/common/builds/Fred/EventFilter/evtPrunerTChainMultiple.C(&merit, &svac,  myCuts, "output.root")
    • '&merit' is either the Merit or SVAC TChain you want to make a cut on.
    • '&svac' is either the Merit or SVAC TChain you want to filter
    • 'myCuts' are your cuts.
    • 'output.root' is the name of the output Merit/SVAC root file.
  • Note that you can only filter one file at the time (Merit or SVAC). If you want to prune both SVAC and Merit you have to run it twice.
  • Note that all four pruning combinations of SVAC and Merit are valid i.e. (&merit, &svac), (&merit, &merit), (&svac, &merit) and (&svac, &svac) are all OK.