// @(#)root/roostats:$Id:  cranmer $
// Author: Kyle Cranmer, Akira Shibata
/*************************************************************************
 * 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.             *
 *************************************************************************/

//_________________________________________________
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#include "RooFit.h"

#include "Riostream.h"
#include "Riostream.h"
#include <math.h>
#include "TMath.h"

#include "RooAbsReal.h"
#include "RooRealVar.h"
#include "RooArgList.h"
#include "RooMsgService.h"
#include "TMath.h"

#include "RooStats/HistFactory/LinInterpVar.h"

using namespace std;

ClassImp(RooStats::HistFactory::LinInterpVar)

using namespace RooStats;
using namespace HistFactory;

//_____________________________________________________________________________
LinInterpVar::LinInterpVar()
{
  // Default constructor
  _paramIter = _paramList.createIterator() ;
  _nominal = 0 ;
}


//_____________________________________________________________________________
LinInterpVar::LinInterpVar(const char* name, const char* title, 
		       const RooArgList& paramList, 
		       double nominal, vector<double> low, vector<double> high) :
  RooAbsReal(name, title),
  _paramList("paramList","List of paramficients",this),
  _nominal(nominal), _low(low), _high(high)
{

  _paramIter = _paramList.createIterator() ;


  TIterator* paramIter = paramList.createIterator() ;
  RooAbsArg* param ;
  while((param = (RooAbsArg*)paramIter->Next())) {
    if (!dynamic_cast<RooAbsReal*>(param)) {
      coutE(InputArguments) << "LinInterpVar::ctor(" << GetName() << ") ERROR: paramficient " << param->GetName() 
			    << " is not of type RooAbsReal" << endl ;
      assert(0) ;
    }
    _paramList.add(*param) ;
  }
  delete paramIter ;

}

//_____________________________________________________________________________
LinInterpVar::LinInterpVar(const char* name, const char* title) :
  RooAbsReal(name, title),
  _paramList("paramList","List of coefficients",this)
{
  // Constructor of flat polynomial function

  _paramIter = _paramList.createIterator() ;
}

//_____________________________________________________________________________
LinInterpVar::LinInterpVar(const LinInterpVar& other, const char* name) :
  RooAbsReal(other, name), 
  _paramList("paramList",this,other._paramList),
  _nominal(other._nominal), _low(other._low), _high(other._high)
  
{
  // Copy constructor
  _paramIter = _paramList.createIterator() ;
  
}


//_____________________________________________________________________________
LinInterpVar::~LinInterpVar() 
{
  // Destructor
  delete _paramIter ;
}




//_____________________________________________________________________________
Double_t LinInterpVar::evaluate() const 
{
  // Calculate and return value of polynomial

  Double_t sum(_nominal) ;
  _paramIter->Reset() ;

  RooAbsReal* param ;
  //const RooArgSet* nset = _paramList.nset() ;
  int i=0;

  while((param=(RooAbsReal*)_paramIter->Next())) {
    //    param->Print("v");

    if(param->getVal()>0)
      sum +=  param->getVal()*(_high.at(i) - _nominal );
    else
      sum += param->getVal()*(_nominal - _low.at(i));

    ++i;
  }

  if(sum<=0) {
    sum=1E-9;
  }    

  return sum;
}