RooSecondMoment.cxx

Go to the documentation of this file.

/*****************************************************************************
 * Project: RooFit                                                           *
 * Package: RooFitCore                                                       *
 * @(#)root/roofitcore:$Id$
 * Authors:                                                                  *
 *   WV, Wouter Verkerke, UC Santa Barbara, verkerke@slac.stanford.edu       *
 *   DK, David Kirkby,    UC Irvine,         dkirkby@uci.edu                 *
 *                                                                           *
 * Copyright (c) 2000-2005, Regents of the University of California          *
 *                          and Stanford University. All rights reserved.    *
 *                                                                           *
 * Redistribution and use in source and binary forms,                        *
 * with or without modification, are permitted according to the terms        *
 * listed in LICENSE (http://roofit.sourceforge.net/license.txt)             *
 *****************************************************************************/
 
/**
\file RooSecondMoment.cxx
\class RooSecondMoment
\ingroup Roofitcore
**/
 
#include "RooSecondMoment.h"
#include "RooAbsReal.h"
#include "RooAbsPdf.h"
#include "RooArgSet.h"
#include "RooRealVar.h"
#include "RooGlobalFunc.h"
#include "RooConstVar.h"
#include "RooRealIntegral.h"
#include "RooNumIntConfig.h"
#include "RooFormulaVar.h"
#include "RooLinearVar.h"
#include "RooProduct.h"
 
#include <string>
#include <cmath>
#include <ostream>
 
using std::string;
 
////////////////////////////////////////////////////////////////////////////////
 
RooSecondMoment::RooSecondMoment(const char* name, const char* title, RooAbsReal& func, RooRealVar& x, bool centr, bool takeRoot) :
  RooAbsMoment(name, title,func,x,2,takeRoot),
  _xf("!xf","xf",this,false,false),
  _ixf("!ixf","ixf",this),
  _if("!if","if",this),
  _xfOffset(0)
{
  setExpensiveObjectCache(func.expensiveObjectCache()) ;
 
  std::unique_ptr<RooAbsReal> XF;
  if (centr) {
 
     std::string m1name = std::string{GetName()} + "_moment1";
     _mean.putOwnedArg(std::unique_ptr<RooAbsMoment>{func.mean(x)});
 
     std::string pname = std::string{name} + "_product";
     _xfOffset = _mean->getVal();
     std::stringstream formula;
     formula << "std::pow((@0-" << _xfOffset << "),2) * @1";
     XF = std::make_unique<RooFormulaVar>(pname.c_str(), formula.str().c_str(), RooArgList(x, func));
 
  } else {
 
     std::string pname = std::string{name} + "_product";
     XF = std::make_unique<RooProduct>(pname.c_str(), pname.c_str(), RooArgList(x, x, func));
  }
 
  XF->setExpensiveObjectCache(func.expensiveObjectCache()) ;
 
  if (func.isBinnedDistribution(x)) {
    XF->specialIntegratorConfig(true)->method1D().setLabel("RooBinIntegrator");
  }
 
  std::unique_ptr<RooAbsReal> intXF{XF->createIntegral(x)};
  std::unique_ptr<RooAbsReal> intF{func.createIntegral(x)};
  static_cast<RooRealIntegral&>(*intXF).setCacheNumeric(true) ;
  static_cast<RooRealIntegral&>(*intF).setCacheNumeric(true) ;
 
  _xf.setArg(*XF) ;
  _ixf.setArg(*intXF) ;
  _if.setArg(*intF) ;
  addOwnedComponents(std::move(XF)) ;
  addOwnedComponents(std::move(intXF));
  addOwnedComponents(std::move(intF));
}
 
////////////////////////////////////////////////////////////////////////////////
 
RooSecondMoment::RooSecondMoment(const char* name, const char* title, RooAbsReal& func, RooRealVar& x, const RooArgSet& nset,
           bool centr, bool takeRoot, bool intNSet) :
  RooAbsMoment(name, title,func,x,2,takeRoot),
  _xf("!xf","xf",this,false,false),
  _ixf("!ixf","ixf",this),
  _if("!if","if",this),
  _xfOffset(0)
{
  setExpensiveObjectCache(func.expensiveObjectCache()) ;
 
  _nset.add(nset) ;
 
  std::unique_ptr<RooAbsReal> XF;
  if (centr) {
 
     std::string m1name = std::string{GetName()} + "_moment1";
     _mean.putOwnedArg(std::unique_ptr<RooAbsMoment>{func.mean(x, nset)});
 
     std::string pname = std::string{name} + "_product";
     _xfOffset = _mean->getVal();
     std::stringstream formula;
     formula << "std::pow((@0-" << _xfOffset << "),2) * @1";
     XF = std::make_unique<RooFormulaVar>(pname.c_str(), formula.str().c_str(), RooArgList(x, func));
 
  } else {
 
     std::string pname = std::string{name} + "_product";
     XF = std::make_unique<RooProduct>(pname.c_str(), pname.c_str(), RooArgList(x, x, func));
  }
 
  XF->setExpensiveObjectCache(func.expensiveObjectCache()) ;
 
  if (func.isBinnedDistribution(x)) {
    XF->specialIntegratorConfig(true)->method1D().setLabel("RooBinIntegrator");
  }
  if (intNSet && !_nset.empty() && func.isBinnedDistribution(_nset)) {
      XF->specialIntegratorConfig(true)->method2D().setLabel("RooBinIntegrator");
      XF->specialIntegratorConfig(true)->methodND().setLabel("RooBinIntegrator");
  }
 
  RooArgSet intSet(x) ;
  if (intNSet) intSet.add(_nset,true) ;
  std::unique_ptr<RooAbsReal> intXF{XF->createIntegral(intSet, &_nset)};
  std::unique_ptr<RooAbsReal> intF{func.createIntegral(intSet, &_nset)};
  static_cast<RooRealIntegral&>(*intXF).setCacheNumeric(true) ;
  static_cast<RooRealIntegral&>(*intF).setCacheNumeric(true) ;
 
  _xf.setArg(*XF) ;
  _ixf.setArg(*intXF) ;
  _if.setArg(*intF) ;
  addOwnedComponents(std::move(XF)) ;
  addOwnedComponents(std::move(intXF));
  addOwnedComponents(std::move(intF));
}
 
 
 
////////////////////////////////////////////////////////////////////////////////
 
RooSecondMoment::RooSecondMoment(const RooSecondMoment& other, const char* name) :
  RooAbsMoment(other, name),
  _xf("xf",this,other._xf),
  _ixf("ixf",this,other._ixf),
  _if("if",this,other._if),
  _xfOffset(other._xfOffset)
{
}
 
////////////////////////////////////////////////////////////////////////////////
/// Calculate value
 
double RooSecondMoment::evaluate() const
{
  double ratio = _ixf / _if ;
 
  if (_mean.absArg()) {
    ratio -= (_mean - _xfOffset)*(_mean-_xfOffset) ;
  }
 
  double ret =  _takeRoot ? sqrt(ratio) : ratio ;
  return ret ;
}