class AtlAnalysisTool: public TNamed

 Abstract base class for ATLAS analysis tools

 The purpose of this class is to provide analysis tools consisting
 of analysis code which might be useful in many analyses (eg a
 particle decay finder).

 A tool is added to an analysis selector by using
 AtlSelector::AddTool(). The selector can include more than one tool
 (it is even possible to run the same tool twice with different
 parameters). Tools are named classes and can be accessed via their
 names from the list of tools held by the AtlSelector class.

 A tool can be plugged at different positions into the analysis. The
 selector allows for two different user-defnied analysis routines,
 one for a crude event preselection (AtlSelector::ProcessPreCut()),
 and the other for the main analysis and event selection
 (AtlSelector::ProcessCut()). The tool can be placed either before
 both of them, in between or at the very end. A decay finder for
 instance, would be placed best in between the preselection and the
 main event selection. This would allow to run the finder only over
 those events which are of special interest, while not loosing any
 time to analsye the rest of them.
 Additionally there might be the need for tools that either change
 or correct kinematic variables, alter the event weight or fulfill
 other tasks.
 For this a series of insertion points are available. In order to
 see clearly where the tools are invoked, have a look at the Process()
 routine of the AtlSelector class.
 Two process modes have to be mentionend in particular:
 The mode kIndividual gives the user the possibility to invoke the
 tool at a point where the user desires it. The tool is invoked via
 tool->Process().
 The mode kOff switches a tool of by removing it from the list of
 registered tools. This makes it possible to keep code that handles
 the setup of tools while dynamically switching on and off the tool.


 The steering is done with the (public) datamember fProcessMode.

 Inter-tool communications can be performed easily in the following way:

   insidde tool A {

     ClassToolB *toolb = fParent->GetTool("ClassToolB");
     toolB->DoSomething();
   }


 Author: Oliver Maria Kind <mailto: kind@mail.desy.de>
 Update: $Id: AtlAnalysisTool.cxx,v 1.16 2016/01/29 21:12:20 kind Exp $
 Copyright: 2009 (C) Oliver Maria Kind