RooNumIntFactory.cxx

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/*****************************************************************************
 * 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 RooNumIntFactory.cxx
\class RooNumIntFactory
\ingroup Roofitcore
 
%Factory to instantiate numeric integrators
from a given function binding and a given configuration. The factory
searches for a numeric integrator registered with the factory that
has the ability to perform the numeric integration. The choice of
method may depend on the number of dimensions integrated,
the nature of the integration limits (closed or open ended) and
the preference of the caller as encoded in the configuration object.
**/
 
#include "TSystem.h"
 
#include "RooNumIntFactory.h"
#include "RooArgSet.h"
#include "RooAbsFunc.h"
#include "RooNumIntConfig.h"
#include "RooNumber.h"
#include "RooRombergIntegrator.h"
#include "RooBinIntegrator.h"
#include "RooImproperIntegrator1D.h"
#include "RooMCIntegrator.h"
#include "RooAdaptiveIntegratorND.h"
#include "RooMsgService.h"
 
#include <ostream>
 
////////////////////////////////////////////////////////////////////////////////
/// Register all known integrators by calling
/// their static registration functions
void RooNumIntFactory::init() {
  RooBinIntegrator::registerIntegrator(*this) ;
  RooRombergIntegrator::registerIntegrator(*this) ;
  RooImproperIntegrator1D::registerIntegrator(*this) ;
  RooMCIntegrator::registerIntegrator(*this) ;
  // GSL integrator is now in RooFitMore and it register itself
  //RooAdaptiveGaussKronrodIntegrator1D::registerIntegrator(*this) ;
  //RooGaussKronrodIntegrator1D::registerIntegrator(*this) ;
  RooAdaptiveIntegratorND::registerIntegrator(*this) ;
 
  RooNumIntConfig::defaultConfig().method1D().setLabel("RooIntegrator1D") ;
  RooNumIntConfig::defaultConfig().method1DOpen().setLabel("RooImproperIntegrator1D") ;
  RooNumIntConfig::defaultConfig().method2D().setLabel("RooAdaptiveIntegratorND") ;
  RooNumIntConfig::defaultConfig().methodND().setLabel("RooAdaptiveIntegratorND") ;
 
  //if GSL is available load (and register GSL integrator)
#ifdef R__HAS_MATHMORE
  int iret = gSystem->Load("libRooFitMore");
  if (iret < 0) {
     oocoutE(nullptr, Integration) << " RooNumIntFactory::Init : libRooFitMore cannot be loaded. GSL integrators will not be available ! " << std::endl;
  }
#endif
}
 
 
////////////////////////////////////////////////////////////////////////////////
/// Static method returning reference to singleton instance of factory
 
RooNumIntFactory& RooNumIntFactory::instance()
{
  static std::unique_ptr<RooNumIntFactory> instance;
 
  if (!instance) {
    // This is needed to break a deadlock. During init(),
    // other functions may call back to this one here. So we need to construct first,
    // and ensure that we can return an instance while we are waiting for init()
    // to finish.
    instance.reset(new RooNumIntFactory);
    instance->init();
  }
 
  return *instance;
}
 
 
 
////////////////////////////////////////////////////////////////////////////////
/// Method accepting registration of a prototype numeric integrator along with a RooArgSet of its
/// default configuration options and an optional list of names of other numeric integrators
/// on which this integrator depends. Returns true if integrator was previously registered
 
bool RooNumIntFactory::registerPlugin(std::string const &name, Creator const &creator, const RooArgSet &defConfig,
                                    bool canIntegrate1D, bool canIntegrate2D, bool canIntegrateND,
                                    bool canIntegrateOpenEnded, const char *depName)
{
  if (_map.find(name) != _map.end()) {
    //cout << "RooNumIntFactory::storeIntegrator() ERROR: integrator '" << name << "' already registered" << std::endl ;
    return true ;
  }
 
  // Add to factory
  auto& info = _map[name];
  info.creator = creator;
  info.canIntegrate1D = canIntegrate1D;
  info.canIntegrate2D = canIntegrate2D;
  info.canIntegrateND = canIntegrateND;
  info.canIntegrateOpenEnded = canIntegrateOpenEnded;
  info.depName = depName;
 
  // Add default config to master config
  RooNumIntConfig::defaultConfig().addConfigSection(name,defConfig, canIntegrate1D, canIntegrate2D, canIntegrateND, canIntegrateOpenEnded) ;
 
  return false ;
}
 
std::string RooNumIntFactory::getIntegratorName(RooAbsFunc& func, const RooNumIntConfig& config, int ndimPreset, bool isBinned) const
{
  // First determine dimensionality and domain of integrand
  int ndim = ndimPreset>0 ? ndimPreset : ((int)func.getDimension()) ;
 
  bool openEnded = false ;
  int i ;
  for (i=0 ; i<ndim ; i++) {
    if(RooNumber::isInfinite(func.getMinLimit(i)) ||
       RooNumber::isInfinite(func.getMaxLimit(i))) {
      openEnded = true ;
    }
  }
 
  // Find method defined configuration
  std::string method ;
  switch(ndim) {
  case 1:
    method = openEnded ? config.method1DOpen().getCurrentLabel() : config.method1D().getCurrentLabel() ;
    break ;
 
  case 2:
    method = openEnded ? config.method2DOpen().getCurrentLabel() : config.method2D().getCurrentLabel() ;
    break ;
 
  default:
    method = openEnded ? config.methodNDOpen().getCurrentLabel() : config.methodND().getCurrentLabel() ;
    break ;
  }
 
  // If distribution is binned and not open-ended override with bin integrator
  if (isBinned & !openEnded) {
    method = "RooBinIntegrator" ;
  }
 
  // Check that a method was defined for this case
  if (method == "N/A") {
    oocoutE(nullptr,Integration) << "RooNumIntFactory: No integration method has been defined for "
                 << (openEnded?"an open ended ":"a ") << ndim << "-dimensional integral" << std::endl;
    return {};
  }
 
  return method;
}
 
////////////////////////////////////////////////////////////////////////////////
/// Construct a numeric integrator instance that operates on function 'func' and is configured
/// with 'config'. If ndimPreset is greater than zero that number is taken as the dimensionality
/// of the integration, otherwise it is queried from 'func'. This function iterators over list
/// of available prototype integrators and returns an clone attached to the given function of
/// the first class that matches the specifications of the requested integration considering
/// the number of dimensions, the nature of the limits (open ended vs closed) and the user
/// preference stated in 'config'
 
std::unique_ptr<RooAbsIntegrator> RooNumIntFactory::createIntegrator(RooAbsFunc& func, const RooNumIntConfig& config, int ndimPreset, bool isBinned) const
{
  std::string method = getIntegratorName(func, config, ndimPreset, isBinned);
 
  if(method.empty()) {
    return nullptr;
  }
 
  // Retrieve proto integrator and return clone configured for the requested integration task
  std::unique_ptr<RooAbsIntegrator> engine =  getPluginInfo(method)->creator(func,config) ;
  if (config.printEvalCounter()) {
    engine->setPrintEvalCounter(true) ;
  }
  return engine ;
}