Inheritance diagram for CandViewRefRandomSelector:

Public Member Functions
	CandViewRefRandomSelector (const edm::ParameterSet &pset)

bool	filter (edm::Event &, const edm::EventSetup &)

Public Member Functions inherited from edm::EDFilter
	EDFilter ()

virtual	~EDFilter ()

Public Member Functions inherited from edm::ProducerBase
	ProducerBase ()

void	registerProducts (ProducerBase , ProductRegistry , ModuleDescription const &)

boost::function< void(const BranchDescription &)>	registrationCallback () const
	used by the fwk to register list of products More...

virtual	~ProducerBase ()

Private Attributes
unsigned int	choose_

bool	filter_

TRandom3	randy_

unsigned int	seed_

edm::InputTag	src_

Additional Inherited Members
Public Types inherited from edm::EDFilter
typedef EDFilter	ModuleType

typedef WorkerT< EDFilter >	WorkerType

Public Types inherited from edm::ProducerBase
typedef ProductRegistryHelper::TypeLabelList	TypeLabelList

Static Public Member Functions inherited from edm::EDFilter
static const std::string &	baseType ()

static void	fillDescriptions (ConfigurationDescriptions &descriptions)

static void	prevalidate (ConfigurationDescriptions &)

Protected Member Functions inherited from edm::EDFilter
CurrentProcessingContext const *	currentContext () const

Protected Member Functions inherited from edm::ProducerBase
template<class TProducer , class TMethod >
void	callWhenNewProductsRegistered (TProducer *iProd, TMethod iMethod)

Detailed Description

Definition at line 25 of file CandViewRefRandomSelector.cc.

Constructor & Destructor Documentation

CandViewRefRandomSelector::CandViewRefRandomSelector ( const edm::ParameterSet & pset )

explicit

Definition at line 37 of file CandViewRefRandomSelector.cc.

References choose_, edm::ParameterSet::exists(), filter_, edm::ParameterSet::getParameter(), randy_, seed_, and src_.

                                  {
   src_ = pset.getParameter<edm::InputTag>("src");
   choose_ = pset.getParameter<unsigned int>("choose");
   filter_ = pset.getParameter<bool>("filter");
   seed_ = pset.exists("seed") ? pset.getParameter<unsigned int>("seed") : 123;
   randy_ = TRandom3(seed_);
   produces<reco::CandidateBaseRefVector>();
 }

Member Function Documentation

bool CandViewRefRandomSelector::filter	(	edm::Event &	evt,
		const edm::EventSetup &	es
	)

virtual

Implements edm::EDFilter.

Definition at line 47 of file CandViewRefRandomSelector.cc.

References choose_, filter_, edm::Event::getByLabel(), i, convertSQLitetoXML_cfg::output, edm::RefToBaseVector< T >::push_back(), edm::Event::put(), randy_, edm::RefToBaseVector< T >::size(), and src_.

                                                                 {
   edm::Handle<edm::View<reco::Candidate> > cands;
   evt.getByLabel(src_, cands);
   std::auto_ptr<reco::CandidateBaseRefVector> output(
       new reco::CandidateBaseRefVector(cands));
   // If we don't have enough elements to select, just copy what we have
   const reco::CandidateBaseRefVector &inputRefs = cands->refVector();
   if (inputRefs.size() <= choose_) {
     *output = inputRefs;
   } else {
     for (size_t i = 0; i < inputRefs.size() && output->size() < choose_; ++i) {
       // based on http://stackoverflow.com/questions/48087/
       // select-a-random-n-elements-from-listt-in-c/48089#48089
       double selectionProb =
           (choose_ - output->size())*1.0/(inputRefs.size() - i);
       // throw a number to see if we select this element
       if (randy_.Rndm() < selectionProb)
         output->push_back(inputRefs[i]);
     }
   }
   size_t outputSize = output->size();
   evt.put(output);
   return ( !filter_ || outputSize );
 }