class AtlRunEvtSelectionTool: public AtlAnalysisTool

 Run/Event Selection Tool

 With the help of this tool an analysis can be run over a
 pre-selected list of events either given by a text file or by a
 flat Root tree. The tool is designed fot high speed and good
 performance, also for large lists.

 Usage:

 Note that when using tasks the content of the tool's data members
 can be set by using AtlAppAnalysiTask::AtlSetToolVariable() in the
 usual way.

 (1) Create tool with text file:
 AtlRunEvtSelectionTool *tool = new AtlRunEvtSelectionTool("runevttool", "Run/Evt Selection Tool");
 tool->fInputName("runevt.dat");

 The file runevt.dat looks like (events can be disordered):
 1243393 1020
 1243393 998
 1243393 2346
 1243393 10044
 1243355 25

 In case the file has a different format, the format string for
 reading the file can be stored by the data member fInputFormat.

 (2) Create tool with ntuple:
 AtlRunEvtSelectionTool *tool = new AtlRunEvtSelectionTool("runevt_tool", "RunEvt Tool")
 tool->fInputFilename = "AntiElectronQCDModel.root"
 tool->fInputTreename = "AntiElectrons"
 tool->fBranchnameRun = "runnumber"
 tool->fBranchnameEvent = "eventnumber"

 (3) Inside the analysis simply ask by using
 Bool_t IsValid = tool->IsValidEvent();
 if the current event is contained in the list. This information can
 be used, for instance, in ProcessCuut to select only the given
 events. In a similar way an inverted selection would be possible as
 well.  The tool makes it easy to convert a given list (text fiel or
 ntuple) into an EntryList which can be used in a subsequent
 analysis.


 Author: Oliver Maria Kind <mailto: kind@mail.desy.de>
 Update: $Id: AtlRunEvtSelectionTool.cxx,v 1.3 2011/06/09 08:17:35 kind Exp $
 Copyright: 2011 (C) Oliver Maria Kind