Lifetime PDF with per-event acceptance


Firstly, I’d like to thank the RooFit team for the extremely useful RooFit tutorials, especially number 314 which shows how to fit to lifetime data where each event has a minimum time, a “turning point”, before which it would not be accepted. I.e. the PDF looks something like this:

I am trying to develop a PDF which would accommodate data which has multiple turning points:

Before I attempt to write a specific PDF class, is there a way I could adapt the tutorial example?

If I understand the turorial, then the acceptance is taken into account via the range of allowed time values set by ProtoData. It seems that defining multiple ranges, i.e. x in [0,1] && [2,3], will not work in this case.

Does anyone have suggestions on how I should proceed?



EDIT: Edited to allow inline png examples.

After discussions with Wouter, it was decided that processing data with N acceptance regions could be dealt with through the use of N ranges:

  t.setRange("A",0,5) ;
  t.setRange("B",10,15) ;

  // Make pdf
  RooRealVar tau( "tau", "tau", -1.54, -10, -1.0 ) ;
  RooExponential model( "model", "model", t, tau ) ;

  // Set range for fitting/generating