// @(#)root/roostats:$Id$
// Author: Kyle Cranmer, Lorenzo Moneta, Gregory Schott, Wouter Verkerke
 * Copyright (C) 1995-2008, Rene Brun and Fons Rademakers.               *
 * All rights reserved.                                                  *
 *                                                                       *
 * For the licensing terms see $ROOTSYS/LICENSE.                         *
 * For the list of contributors see $ROOTSYS/README/CREDITS.             *

#ifndef ROOSTATS_IntervalCalculator
#define ROOSTATS_IntervalCalculator

IntervalCalculator is an interface class for a tools which produce RooStats ConfIntervals.  
The interface currently assumes that any interval calculator can be configured by specifying:
 <li>a model,</li>
 <li>a data set, </li>
 <li>a set of parameters of interest,</li>
 <li>a set of nuisance parameters (eg. parameters on which the model depends, but are not of interest), and </li>
 <li>a confidence level or size of the test (eg. rate of Type I error).</li>
The interface allows one to pass the model, data, and parameters via a workspace and then specify them with names.
The interface will be extended so that one does not need to use a workspace.
After configuring the calculator, one only needs to ask GetInterval, which will return a ConfInterval pointer.
The concrete implementations of this interface should deal with the details of how the nuisance parameters are
dealt with (eg. integration vs. profiling) and which test-statistic is used (perhaps this should be added to the interface).
The motivation for this interface is that we hope to be able to specify the problem in a common way for several concrete calculators.

#ifndef ROOT_Rtypes
#include "Rtypes.h"
//#include "TNamed.h"

class RooAbsData; 
class RooWorkspace; 

namespace RooStats {

   class ConfInterval; 

   class ModelConfig; 

   class IntervalCalculator { 


      virtual ~IntervalCalculator() {}
      // Main interface to get a ConfInterval, pure virtual
      virtual ConfInterval* GetInterval() const = 0; 

      // Get the size of the test (eg. rate of Type I error)
      virtual Double_t Size() const = 0;

      // Get the Confidence level for the test
      virtual Double_t ConfidenceLevel()  const = 0;  

      // Set the DataSet ( add to the the workspace if not already there ?)
      virtual void SetData(RooAbsData&) = 0;

      // Set the Model 
      virtual void SetModel(const ModelConfig & /* model */) = 0; 

      // set the size of the test (rate of Type I error) ( e.g. 0.05 for a 95% Confidence Interval)
      virtual void SetTestSize(Double_t size) = 0;

      // set the confidence level for the interval (e.g. 0.95 for a 95% Confidence Interval)
      virtual void SetConfidenceLevel(Double_t cl) = 0;
      ClassDef(IntervalCalculator,1)   // Interface for tools setting limits (producing confidence intervals)