RooFunctorBinding.cxx

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/*****************************************************************************
 * Project: RooFit                                                           *
 * Package: RooFitCore                                                       *
 *    File: $Id$
 * Authors:                                                                  *
 *   WV, Wouter Verkerke, NIKHEF, verkerke@nikhef.nl                         *
 *                                                                           *
 * Copyright (c) 2000-2008, NIKHEF, Regents of the University of California  *
 *                          and Stanford University. All rights reserved.    *
 *                                                                           *
 *****************************************************************************/

/**
\file RooFunctorBinding.cxx
\class RooFunctorBinding
\ingroup Roofit

RooCFunction1Binding is a templated implementation of class RooAbsReal that binds 
generic C(++) functions to a RooAbsReal argument thus allowing generic C++
functions to be used as RooFit functions. Instances of function binding
classes are fully functional RooFit function objects with one exception:
if the bound function is _not_ a standard TMath or MathMore function the
class cannot be persisted in a RooWorkspace without registering the function
pointer first using RooCFunction1Binding<T1,T2>::register().
**/

#include "Riostream.h" 
#include "RooFunctorBinding.h" 

using namespace std ;

ClassImp(RooFunctorBinding) 
ClassImp(RooFunctorPdfBinding) 
  ;


RooFunctorBinding::RooFunctorBinding(const char *name, const char *title, const ROOT::Math::IBaseFunctionMultiDim& ftor, const RooArgList& v) :
  RooAbsReal(name,title), 
  func(&ftor),
  vars("vars","vars",this) 
{ 
  // Check that function dimension and number of variables match 
  if (ftor.NDim()!=UInt_t(v.getSize())) {
    coutE(InputArguments) << "RooFunctorBinding::ctor(" << GetName() << ") ERROR number of provided variables (" << v.getSize() 
           << ") does not match dimensionality of function (" << ftor.NDim() << ")" << endl ;
    throw string("RooFunctor::ctor ERROR") ;
  }
  x = new Double_t[func->NDim()] ;
  vars.add(v) ;
} 


RooFunctorBinding::RooFunctorBinding(const RooFunctorBinding& other, const char* name) :  
  RooAbsReal(other,name), 
  func(other.func),
  vars("vars",this,other.vars)
{ 
  // Copy constructor
  x = new Double_t[func->NDim()] ;
} 



void RooFunctorBinding::printArgs(ostream& os) const {
  // Print object arguments and name/address of function pointer
  os << "[ function=" << func << " " ;    
  for (Int_t i=0 ; i<numProxies() ; i++) {
    RooAbsProxy* p = getProxy(i) ;
    if (!TString(p->name()).BeginsWith("!")) {
      p->print(os) ;
      os << " " ;
    }
  }    
  os << "]" ;  
}

Double_t RooFunctorBinding::evaluate() const {
    // Return value of embedded function using value of referenced variable x
    for (int i=0 ; i<vars.getSize() ; i++) {
      x[i] = ((RooAbsReal*)vars.at(i))->getVal() ;
    }
    return (*func)(x) ;
  }



RooFunctorPdfBinding::RooFunctorPdfBinding(const char *name, const char *title, const ROOT::Math::IBaseFunctionMultiDim& ftor, const RooArgList& v) :
  RooAbsPdf(name,title), 
  func(&ftor),
  vars("vars","vars",this) 
{ 
  // Check that function dimension and number of variables match 
  if (ftor.NDim()!=UInt_t(v.getSize())) {
    coutE(InputArguments) << "RooFunctorPdfBinding::ctor(" << GetName() << ") ERROR number of provided variables (" << v.getSize() 
           << ") does not match dimensionality of function (" << ftor.NDim() << ")" << endl ;
    throw string("RooFunctor::ctor ERROR") ;
  }
  x = new Double_t[func->NDim()] ;
  vars.add(v) ;
} 


RooFunctorPdfBinding::RooFunctorPdfBinding(const RooFunctorPdfBinding& other, const char* name) :  
  RooAbsPdf(other,name), 
  func(other.func),
  vars("vars",this,other.vars)
{ 
  // Copy constructor
  x = new Double_t[func->NDim()] ;
} 



void RooFunctorPdfBinding::printArgs(ostream& os) const {
  // Print object arguments and name/address of function pointer
  os << "[ function=" << func << " " ;    
  for (Int_t i=0 ; i<numProxies() ; i++) {
    RooAbsProxy* p = getProxy(i) ;
    if (!TString(p->name()).BeginsWith("!")) {
      p->print(os) ;
      os << " " ;
    }
  }    
  os << "]" ;  
}

Double_t RooFunctorPdfBinding::evaluate() const {
    // Return value of embedded function using value of referenced variable x
    for (int i=0 ; i<vars.getSize() ; i++) {
      x[i] = ((RooAbsReal*)vars.at(i))->getVal() ;
    }
    return (*func)(x) ;
  }




namespace RooFit {

  RooAbsReal* bindFunction(const char* name, const ROOT::Math::IBaseFunctionMultiDim& ftor,const RooArgList& vars) {
    return new RooFunctorBinding(name,name,ftor,vars) ;
  }

  RooAbsPdf*  bindPdf(const char* name, const ROOT::Math::IBaseFunctionMultiDim& ftor, const RooArgList& vars) {
    return new RooFunctorPdfBinding(name,name,ftor,vars) ;
  }

}