evgb::util Namespace Reference

Functions
template<class PRODUCER , class T , class U >
bool	CreateAssn (PRODUCER const &prod, art::Event &evt, std::vector< T > const &a, art::Ptr< U > const &b, art::Assns< U, T > &assn, std::string a_instance, size_t indx=UINT_MAX)
	Creates a single one-to-one association. More...
template<class PRODUCER , class T , class U >
bool	CreateAssn (PRODUCER const &prod, art::Event &evt, std::vector< T > const &a, art::Ptr< U > const &b, art::Assns< U, T > &assn, size_t indx=UINT_MAX)
	Creates a single one-to-one association. More...
template<class PRODUCER , class T , class U >
bool	CreateAssn (PRODUCER const &prod, art::Event &evt, art::Ptr< T > const &a, art::Ptr< U > const &b, art::Assns< U, T > &assn)
	Creates a single one-to-one association. More...
template<class PRODUCER , class T , class U >
bool	CreateAssn (PRODUCER const &prod, art::Event &evt, std::vector< T > const &a, art::PtrVector< U > const &b, art::Assns< T, U > &assn, size_t indx=UINT_MAX)
	Creates a single one-to-many association. More...
template<class PRODUCER , class T , class U >
bool	CreateAssn (PRODUCER const &prod, art::Event &evt, art::Ptr< T > const &a, std::vector< art::Ptr< U >> const &b, art::Assns< T, U > &assn)
	Creates a single one-to-many association. More...
template<class PRODUCER , class T , class U >
bool	CreateAssn (PRODUCER const &prod, art::Event &evt, std::vector< T > const &a, std::vector< art::Ptr< U >> const &b, art::Assns< T, U > &assn, size_t indx=UINT_MAX)
	Creates a single one-to-many association. More...
template<class PRODUCER , class T , class U >
bool	CreateAssn (PRODUCER const &prod, art::Event &evt, std::vector< T > const &a, std::vector< U > const &b, art::Assns< T, U > &assn, size_t startU, size_t endU, size_t indx=UINT_MAX)
	Creates a single one-to-many association. More...
template<class PRODUCER , class T , class U >
bool	CreateAssn (PRODUCER const &prod, art::Event &evt, std::vector< T > const &a, std::vector< U > const &b, art::Assns< T, U > &assn, std::vector< size_t > const &indices, size_t indx=UINT_MAX)
	Creates a single one-to-many association. More...
template<typename PRODUCER , typename T , typename U , typename Iter >
bool	CreateAssn (PRODUCER const &prod, art::Event &evt, art::Assns< T, U > &assn, size_t first_index, Iter from_second_index, Iter to_second_index)
	Creates a single one-to-many association. More...
template<class T , class U >
std::vector< const U * >	FindUNotAssociatedToT (art::Handle< U > b, art::Event const &evt, std::string const &label)
template<class T , class U >
std::vector< art::Ptr< U > >	FindUNotAssociatedToTP (art::Handle< U > b, art::Event const &evt, std::string const &label)
template<class T , class U >
std::vector< size_t >	GetAssociatedVectorOneI (art::Handle< art::Assns< T, U > > h, art::Handle< std::vector< T > > index_p)
template<class T , class U >
std::vector< const U * >	GetAssociatedVectorOneP (art::Handle< art::Assns< T, U > > h, art::Handle< std::vector< T > > index_p)
template<class T , class U >
std::vector< std::vector< size_t > >	GetAssociatedVectorManyI (art::Handle< art::Assns< T, U > > h, art::Handle< std::vector< T > > index_p)
template<class T , class U >
std::vector< std::vector< const U * > >	GetAssociatedVectorManyP (art::Handle< art::Assns< T, U > > h, art::Handle< std::vector< T > > index_p)
template<typename PRODUCER , typename T , typename U , typename D >
bool	CreateAssnD (PRODUCER const &prod, art::Event &evt, art::Assns< T, U, D > &assn, size_t first_index, size_t second_index, typename art::Assns< T, U, D >::data_t &&data)
	Creates a single one-to-one association with associated data. More...
template<typename PRODUCER , typename T , typename U , typename D >
bool	CreateAssnD (PRODUCER const &prod, art::Event &evt, art::Assns< T, U, D > &assn, size_t first_index, size_t second_index, typename art::Assns< T, U, D >::data_t const &data)
	Creates a single one-to-one association with associated data. More...

Function Documentation

template<class PRODUCER , class T , class U >

bool evgb::util::CreateAssn	(	PRODUCER const &	prod,
		art::Event &	evt,
		std::vector< T > const &	a,
		art::Ptr< U > const &	b,
		art::Assns< U, T > &	assn,
		std::string	a_instance,
		size_t	indx = UINT_MAX
	)

Creates a single one-to-one association.

Template Parameters

T	type of the new object to associate
U	type of the object already in the data product or art::Ptr

Parameters

prod	reference to the producer that will write the vector a
evt	reference to the current event
a	vector of data products that are in, or will be put into, evt
b	art::Ptr to the (new) object to be associated to the one in a
assn	reference to association object where the new one will be put
a_instance	name of the instance that will be used for a in evt
indx	index of the element in a to be associated with b (default: the last element)

Returns

whether the operation was successful (can it ever fail??)

As example of usage: create a wire/raw digit association. This code should live in the art::EDProduce::produce() method. The raw::RawDigit product was created already by a DigitModuleLabel module. The code is supposed to produce one recob::Wire for each existing raw::RawDigit, and contextually associate the new wire to the source digit. We are also assuming that there might be different RawDigit sets produced by the same producer: we identify the one we care of by the string spill_name and we create wires and associations with the same label for convenience.

// this is the original list of digits, thawed from the event
art::Handle< std::vector<raw::RawDigit>> digitVecHandle;
evt.getByLabel(DigitModuleLabel, spill_name, digitVecHandle);

// the collection of wires that will be written as data product
std::unique_ptr<std::vector<recob::Wire>> wirecol(new std::vector<recob::Wire>);
// ... and an association set
std::unique_ptr<art::Assns<raw::RawDigit,recob::Wire>> WireDigitAssn
  (new art::Assns<raw::RawDigit,recob::Wire>);

for(size_t iDigit = 0; iDigit < digitVecHandle->size(); ++iDigit) {
  // turn the digit into a art::Ptr:
  art::Ptr<raw::RawDigit> digit_ptr(digitVecHandle, iDigit);

  // store the wire in its final position in the data product;
  // the new wire is currently the last of the list
  wirecol->push_back(std::move(wire));

  // add an association between the last object in wirecol
  // (that we just inserted) and digit_ptr
  if (!evgb::util::CreateAssn(*this, evt, *wirecol, digit_ptr, *WireDigitAssn, spill_name)) {
    throw art::Exception(art::errors::ProductRegistrationFailure)
      << "Can't associate wire #" << (wirecol->size() - 1)
      << " with raw digit #" << digit_ptr.key();
  } // if failed to add association

} // for digits

evt.put(std::move(wirecol), spill_name);
evt.put(std::move(WireDigitAssn), spill_name);

Definition at line 593 of file EVGBAssociationUtil.h.

References art::Assns< L, R, D >::addSingle(), e, art::ProductRetriever::getProductID(), and art::ProductRetriever::productGetter().

Referenced by CreateAssn(), evgen::TestGENIEHelper::produce(), and evg::AddGenieEventsToArt::produce().

{
  if (indx == UINT_MAX) indx = a.size()-1;
  
  try{
    art::ProductID aid = evt.getProductID< std::vector<T>>( a_instance);
    art::Ptr<T> aptr(aid, indx, evt.productGetter(aid));
    assn.addSingle(b, aptr);
    return true;
  }
  catch(cet::exception &e){
    mf::LogWarning("AssociationUtil")
      << "unable to create requested art:Assns, exception thrown: " << e;
    return false;
  }
  
} // evgb::util::CreateAssn() [01]

template<class PRODUCER , class T , class U >

bool evgb::util::CreateAssn ( PRODUCER const &  prod, art::Event &  evt, std::vector< T > const &  a, art::Ptr< U > const &  b, art::Assns< U, T > &  assn, size_t  indx = UINT_MAX  )

inline

Creates a single one-to-one association.

Template Parameters

T	type of the new object to associate
U	type of the object already in the data product or art::Ptr

Parameters

prod	reference to the producer that will write the vector a
evt	reference to the current event
a	vector of data products that are in, or will be put into, evt
b	art::Ptr to the (new) object to be associated to the one in a
assn	reference to association object where the new one will be put
indx	index of the element in a to be associated with b (default: the last element)

Returns

whether the operation was successful (can it ever fail??)

The instance name of the product a will be in is assumed empty. Example of usage:

// this is the original list of digits, thawed from the event
art::Handle< std::vector<raw::RawDigit>> digitVecHandle;
evt.getByLabel(DigitModuleLabel, digitVecHandle);

// the collection of wires that will be written as data product
std::unique_ptr<std::vector<recob::Wire>> wirecol(new std::vector<recob::Wire>);
// ... and an association set
std::unique_ptr<art::Assns<raw::RawDigit,recob::Wire>> WireDigitAssn
  (new art::Assns<raw::RawDigit,recob::Wire>);

for(size_t iDigit = 0; iDigit < digitVecHandle->size(); ++iDigit) {
  // turn the digit into a art::Ptr:
  art::Ptr<raw::RawDigit> digit_ptr(digitVecHandle, iDigit);

  // store the wire in its final position in the data product;
  // the new wire is currently the last of the list
  wirecol->push_back(std::move(wire));

  // add an association between the last object in wirecol
  // (that we just inserted) and digit_ptr
  if (!evgb::util::CreateAssn(*this, evt, *wirecol, digit_ptr, *WireDigitAssn)) {
    throw art::Exception(art::errors::ProductRegistrationFailure)
      << "Can't associate wire #" << (wirecol->size() - 1)
      << " with raw digit #" << digit_ptr.key();
  } // if failed to add association

} // for digits

evt.put(std::move(wirecol));
evt.put(std::move(WireDigitAssn));

Definition at line 214 of file EVGBAssociationUtil.h.

References CreateAssn(), CreateAssnD(), FindUNotAssociatedToT(), FindUNotAssociatedToTP(), GetAssociatedVectorManyI(), GetAssociatedVectorManyP(), GetAssociatedVectorOneI(), GetAssociatedVectorOneP(), geo::vect::indices(), and lar::dump::vector().

    { return CreateAssn(prod, evt, a, b, assn, std::string(), indx); }

template<class PRODUCER , class T , class U >

bool evgb::util::CreateAssn	(	PRODUCER const &	prod,
		art::Event &	evt,
		art::Ptr< T > const &	a,
		art::Ptr< U > const &	b,
		art::Assns< U, T > &	assn
	)

Creates a single one-to-one association.

Template Parameters

T	type of one object to associate
U	type of the other object to associate

Parameters

prod	reference to the producer that will write the vector a
evt	reference to the current event
a	art::Ptr to the first object in the association
b	art::Ptr to the object to be associated to the one in a
assn	reference to association object where the new one will be put

Returns

whether the operation was successful (can it ever fail??)

This is the simplest way ever. Neither the event not the producer references are used.

Definition at line 623 of file EVGBAssociationUtil.h.

References art::Assns< L, R, D >::addSingle(), and e.

  {
  
  try{
    assn.addSingle(b, a);
  }
  catch(cet::exception &e){
    mf::LogWarning("AssociationUtil")
      << "unable to create requested art:Assns, exception thrown: " << e;
    return false;
  }
  
  return true;
} // evgb::util::CreateAssn() [03]

template<class PRODUCER , class T , class U >

bool evgb::util::CreateAssn	(	PRODUCER const &	prod,
		art::Event &	evt,
		std::vector< T > const &	a,
		art::PtrVector< U > const &	b,
		art::Assns< T, U > &	assn,
		size_t	indx = UINT_MAX
	)

Creates a single one-to-many association.

Template Parameters

T	type of the new object to associate
U	type of the many objects already in the data product or art::Ptr

Parameters

prod	reference to the producer that will write the vector a
evt	reference to the current event
a	vector of data products that are in, or will be put into, evt
b	art::PtrVector to the (new) objects to be associated to the one in a
assn	reference to association object where the new one will be put
indx	index of the element in a to be associated with all the ones in b (default: the last element)

Returns

whether the operation was successful (can it ever fail??)

A "one-to-many" association is actually a number of one-to-one associations. If you want to keep the information of the order of the many, you may have to use an association with a data member (the third template parameter that we pretent not to exist).

Definition at line 647 of file EVGBAssociationUtil.h.

References art::Assns< L, R, D >::addSingle(), e, art::ProductRetriever::getProductID(), and art::ProductRetriever::productGetter().

  {
  if(indx == UINT_MAX) indx = a.size() - 1;
  
  try{
    art::ProductID aid = evt.getProductID< std::vector<T> >();
    art::Ptr<T> aptr(aid, indx, evt.productGetter(aid));
    for(art::Ptr<U> const& b_item: b) assn.addSingle(aptr, b_item);
  }
  catch(cet::exception &e){
    mf::LogWarning("AssociationUtil")
      << "unable to create requested art:Assns, exception thrown: " << e;
    return false;
  }
  
  return true;
} // evgb::util::CreateAssn() [04]

template<class PRODUCER , class T , class U >

bool evgb::util::CreateAssn	(	PRODUCER const &	prod,
		art::Event &	evt,
		art::Ptr< T > const &	a,
		std::vector< art::Ptr< U >> const &	b,
		art::Assns< T, U > &	assn
	)

Creates a single one-to-many association.

Template Parameters

T	type of the new object to associate
U	type of the many objects already in the data product or art::Ptr

Parameters

prod	reference to the producer that will write the vector a
evt	reference to the current event
a	art::Ptr to the item to be associated with many
b	vector to art::Ptr to the (new) objects to be associated to a
assn	reference to association object where the new one will be put

Returns

whether the operation was successful (can it ever fail??)

A "one-to-many" association is actually a number of one-to-one associations. If you want to keep the information of the order of the many, you may have to use an association with a data member (the third template parameter that we pretent not to exist).

Definition at line 674 of file EVGBAssociationUtil.h.

References art::Assns< L, R, D >::addSingle(), and e.

  {
  
  try{
    for (art::Ptr<U> const& b_item: b) assn.addSingle(a, b_item);
  }
  catch(cet::exception const& e){
    mf::LogWarning("AssociationUtil")
      << "unable to create requested art:Assns, exception thrown: " << e;
    return false;
  }
  
  return true;
} // evgb::util::CreateAssn() [05]

template<class PRODUCER , class T , class U >

bool evgb::util::CreateAssn	(	PRODUCER const &	prod,
		art::Event &	evt,
		std::vector< T > const &	a,
		std::vector< art::Ptr< U >> const &	b,
		art::Assns< T, U > &	assn,
		size_t	indx = UINT_MAX
	)

Creates a single one-to-many association.

Template Parameters

T	type of the new object to associate
U	type of the many objects already in the data product or art::Ptr

Parameters

prod	reference to the producer that will write the vector a
evt	reference to the current event
a	vector of data products that are in, or will be put into, evt
b	vector to art::Ptr to the (new) objects to be associated to the one in a
assn	reference to association object where the new one will be put
indx	index of the element in a to be associated with all the ones in b (default: the last element)

Returns

whether the operation was successful (can it ever fail??)

A "one-to-many" association is actually a number of one-to-one associations. If you want to keep the information of the order of the many, you may have to use an association with a data member (the third template parameter that we pretent not to exist).

Definition at line 697 of file EVGBAssociationUtil.h.

References art::Assns< L, R, D >::addSingle(), e, art::ProductRetriever::getProductID(), and art::ProductRetriever::productGetter().

  {
  
  if (indx == UINT_MAX) indx = a.size() - 1;
  
  try{
    art::ProductID aid = evt.getProductID< std::vector<T> >();
    art::Ptr<T> aptr(aid, indx, evt.productGetter(aid));
    for (art::Ptr<U> const& b_item: b) assn.addSingle(aptr, b_item);
  }
  catch(cet::exception &e){
    mf::LogWarning("AssociationUtil")
      << "unable to create requested art:Assns, exception thrown: " << e;
    return false;
  }
  
  return true;
} // evgb::util::CreateAssn() [06]

template<class PRODUCER , class T , class U >

bool evgb::util::CreateAssn	(	PRODUCER const &	prod,
		art::Event &	evt,
		std::vector< T > const &	a,
		std::vector< U > const &	b,
		art::Assns< T, U > &	assn,
		size_t	startU,
		size_t	endU,
		size_t	indx = UINT_MAX
	)

Creates a single one-to-many association.

Template Parameters

T	type of the new object to associate
U	type of the many objects already in the data product or art::Ptr

Parameters

prod	reference to the producer that will write the vector a
evt	reference to the current event
a	vector of data products that are in, or will be put into, evt
b	vector of the (new) objects to be associated to the one in a
assn	reference to association object where the new one will be put
startU	index in b of the first element to be associated to the one in a
endU	index in b after the last element to be associated to the one in a
indx	index of the element in a to be associated with all the ones in b (default: the last element)

Returns

whether the operation was successful (can it ever fail??)

Use this when the objects in b are not yet stored in the event and are in a std::vector collection instead.

The method gets the product id for those as well as for the element in a. Also specify the range of entries to use from the std::vector collection of U objects.

A "one-to-many" association is actually a number of one-to-one associations. If you want to keep the information of the order of the many, you may have to use an association with a data member (the third template parameter that we pretent not to exist).

Definition at line 725 of file EVGBAssociationUtil.h.

References art::Assns< L, R, D >::addSingle(), e, art::ProductRetriever::getProductID(), and art::ProductRetriever::productGetter().

  {
  
  if(indx == UINT_MAX) indx = a.size() - 1;
  
  try{
    art::ProductID aid = evt.getProductID< std::vector<T> >();
    art::ProductID bid = evt.getProductID< std::vector<U> >();
    art::Ptr<T> aptr(aid, indx, evt.productGetter(aid));
    auto const* getter = evt.productGetter(bid); // I don't want to know what it is
    for(size_t i = startU; i < endU; ++i){
      art::Ptr<U> bptr(bid, i, getter);
      assn.addSingle(aptr, bptr);
    }
  }
  catch(cet::exception &e){
    mf::LogWarning("AssociationUtil")
      << "unable to create requested art:Assns, exception thrown: " << e;
    return false;
  }
  
  return true;
} // evgb::util::CreateAssn() [07]

template<class PRODUCER , class T , class U >

bool evgb::util::CreateAssn	(	PRODUCER const &	prod,
		art::Event &	evt,
		std::vector< T > const &	a,
		std::vector< U > const &	b,
		art::Assns< T, U > &	assn,
		std::vector< size_t > const &	indices,
		size_t	indx = UINT_MAX
	)

Creates a single one-to-many association.

Template Parameters

T	type of the new object to associate
U	type of the many objects already in the data product or art::Ptr

Parameters

prod	reference to the producer that will write the vector a
evt	reference to the current event
a	vector of data products that are in, or will be put into, evt
b	vector of the (new) objects to be associated to the one in a
assn	reference to association object where the new one will be put
indices	indices of the elements in b to be associated to the one in a
indx	index of the element in a to be associated with all the ones in b (default: the last element)

Returns

whether the operation was successful (can it ever fail??)

Use this when the objects in b are not yet stored in the event and are in a std::vector collection instead.

The method gets the product id for those as well as for the element in a. Also specify the entries to use from the std::vector collection of U objects.

A "one-to-many" association is actually a number of one-to-one associations. If you want to keep the information of the order of the many, you may have to use an association with a data member (the third template parameter that we pretent not to exist).

Definition at line 760 of file EVGBAssociationUtil.h.

References art::Assns< L, R, D >::addSingle(), e, and art::ProductRetriever::productGetter().

  {
  
  if(indx == UINT_MAX) indx = a.size() - 1;
  
  try{
    art::ProductID aid = prod.template getProductID< std::vector<T> >();
    art::ProductID bid = prod.template getProductID< std::vector<U> >();
    art::Ptr<T> aptr(aid, indx, evt.productGetter(aid));
    auto const* getter = evt.productGetter(bid); // I don't want to know what it is
    for(size_t index: indices){
      art::Ptr<U> bptr(bid, index, getter);
      assn.addSingle(aptr, bptr);
    }
  }
  catch(cet::exception &e){
    mf::LogWarning("AssociationUtil")
      << "unable to create requested art:Assns, exception thrown: " << e;
    return false;
  }
  
  return true;
} // evgb::util::CreateAssn() [07a]

template<typename PRODUCER , typename T , typename U , typename Iter >

bool evgb::util::CreateAssn	(	PRODUCER const &	prod,
		art::Event &	evt,
		art::Assns< T, U > &	assn,
		size_t	first_index,
		Iter	from_second_index,
		Iter	to_second_index
	)

Creates a single one-to-many association.

Template Parameters

T	type of the new object to associate
U	type of the many objects already in the data product or art::Ptr
Iter	iterator to size_t-compatible elements

Parameters

prod	reference to the producer that will write the vector a
evt	reference to the current event
assn	reference to association object where the new one will be put
first_index	index of the object of type T to be associated to all the others
from_second_index	iterator pointing to the first of the indices of U type objects to be associated to the one of the first type
to_second_index	iterator pointing after the last of the indices of U type objects to be associated to the one of the first type

Returns

whether the operation was successful (can it ever fail??)

A "one-to-many" association is actually a number of one-to-one associations. If you want to keep the information of the order of the many, you may have to use an association with a data member (the third template parameter that we pretent not to exist).

Use this if the objects that have to be associated to the one of type T are sparse, spread across a to-be-data-product, but you have a list of the indices in the data product of the elements to associate to the one of type T. In other words, given that you have a data product "a" of type std::vector<T> and a data product "b" of type std::vector<U>, this method creates an association betweena[first_index]and b[*(from_second_index)], another between a[first_index] and b[*(from_second_index + 1)], etc.

The surprising concept here is that you don't need to specify neither of the collections of T or U elements. The data product is uniquely defined by its type, producer, process and product label. Here we assume that the type of the products are std::vector<T> and std::vector<U>, and that the products have empty product labels, and that the producer is prod for both of them.

Definition at line 794 of file EVGBAssociationUtil.h.

References art::Assns< L, R, D >::addSingle(), e, and art::ProductRetriever::productGetter().

  {
  
  try{
    // We need the "product ID" of what is going to become a data product.
    // The data product ID is unique for the combination of process, producer,
    // data type and product (instance) label.
    // 
    art::ProductID first_id = prod.template getProductID< std::vector<T> >();
    art::ProductID second_id = prod.template getProductID< std::vector<U> >();
    
    // we declare here that we want to associate the element first_index of the
    // (only) data product of type std::vector<T> with other objects.
    // This is the pointer to that element:
    art::Ptr<T> first_ptr(first_id, first_index, evt.productGetter(first_id));
    
    // we are going to associate that element in a with a number of elements
    // of the only data product of type std::vector<U>
    auto const* getter = evt.productGetter(second_id); // auto, spare me the details
    while (from_second_index != to_second_index) {
      art::Ptr<U> second_ptr(second_id, *from_second_index, getter);
      assn.addSingle(first_ptr, second_ptr);
      ++from_second_index;
    } // while
  }
  catch(cet::exception &e){
    mf::LogWarning("AssociationUtil")
      << "unable to create requested art:Assns, exception thrown: " << e;
    return false;
  }
  
  return true;
} // evgb::util::CreateAssn() [08]

template<typename PRODUCER , typename T , typename U , typename D >

bool evgb::util::CreateAssnD	(	PRODUCER const &	prod,
		art::Event &	evt,
		art::Assns< T, U, D > &	assn,
		size_t	first_index,
		size_t	second_index,
		typename art::Assns< T, U, D >::data_t &&	data
	)

Creates a single one-to-one association with associated data.

Template Parameters

T	type of the new object to associate
U	type of the many objects already in the data product or art::Ptr
D	type of the "metadata" coupled to this pair association

Parameters

prod	reference to the producer that will write the vector a
evt	reference to the current event
assn	reference to association object where the new one will be put
first_index	index of the object of type T to be associated
second_index	index of the object of type U to be associated
data	"metadata" to be store in this association

Returns

whether the operation was successful (can it ever fail??)

Use this if you want some metadata to travel together with the association. An example may be the order of the second element within a list:

size_t a_index = 2;
std::vector<size_t> b_indices{ 6, 9, 18, 12 };
for (size_t i = 0; i < b_indices.size(); ++i)
  CreateAssn(prod, evt, assn, a_index, b_index[i], i);

In this way, the association between the element #2 of "a" (a vector that is not specified – nor needed – in this snippet of code) and the element #18 will be remembered as being the third (metadata value of 2). In this example metadata is of type size_t the association would be declared as art::Assn<A, B, size_t>. A FindMany query of that association might look like:

art::Handle<std::vector<A>> a_list; // read this from the event

art::FindMany<B, size_t> Query(a_list, event, ModuleLabel);

// search for the last of the objects associated to the third element:
size_t a_index = 2; // this means third element

std::vector<size_t const*> const& metadata = Query.data(a_index);
size_t largest_index = 0, last_item = 0;
for (size_t iB = 0; iB < metadata.size(); ++iB) {
  if (largest_index >= *(metadata[iB])) continue;
  largest_index = *(metadata[iB]);
  last_item = iB;
} // for iB
B const& lastB = Query.at(last_item);

In alternative, the elements and their metadata can be fetched simultaneously with:

std::vector<art::Ptr<B>> const& Bs;
std::vector<size_t const*> const& metadata;

size_t a_index = 2; // this means third element
size_t nMatches = Query.get(a_index, Bs, metadata);

Definition at line 838 of file EVGBAssociationUtil.h.

References art::Assns< L, R, D >::addSingle(), e, and art::ProductRetriever::productGetter().

Referenced by CreateAssn().

  {
  
  try{
    // We need the "product ID" of what is going to become a data product.
    // The data product ID is unique for the combination of process, producer,
    // data type and product (instance) label.
    // 
    // we declare here that we want to associate the element first_index of the
    // (only) data product of type std::vector<T> with the other object
    art::ProductID first_id = prod.template getProductID< std::vector<T> >();
    art::Ptr<T> first_ptr(first_id, first_index, evt.productGetter(first_id));
    
    // the same to associate the element second_index of the (only)
    // data product of type std::vector<U> with the first object.
    art::ProductID second_id = prod.template getProductID< std::vector<U> >();
    art::Ptr<U> second_ptr
      (second_id, second_index, evt.productGetter(second_id));
    
    assn.addSingle(first_ptr, second_ptr, std::move(data));
  }
  catch(cet::exception &e){
    mf::LogWarning("AssociationUtil")
      << "unable to create requested art:Assns, exception thrown: " << e;
    return false;
  }
  
  return true;
} // evgb::util::CreateAssnD() [01a]

template<typename PRODUCER , typename T , typename U , typename D >

bool evgb::util::CreateAssnD	(	PRODUCER const &	prod,
		art::Event &	evt,
		art::Assns< T, U, D > &	assn,
		size_t	first_index,
		size_t	second_index,
		typename art::Assns< T, U, D >::data_t const &	data
	)

Creates a single one-to-one association with associated data.

Template Parameters

T	type of the new object to associate
U	type of the many objects already in the data product or art::Ptr
D	type of the "metadata" coupled to this pair association

Parameters

prod	reference to the producer that will write the vector a
evt	reference to the current event
assn	reference to association object where the new one will be put
first_index	index of the object of type T to be associated
second_index	index of the object of type U to be associated
data	"metadata" to be store in this association

Returns

whether the operation was successful (can it ever fail??)

Use this if you want some metadata to travel together with the association. An example may be the order of the second element within a list:

size_t a_index = 2;
std::vector<size_t> b_indices{ 6, 9, 18, 12 };
for (size_t i = 0; i < b_indices.size(); ++i)
  CreateAssn(prod, evt, assn, a_index, b_index[i], i);

In this way, the association between the element #2 of "a" (a vector that is not specified – nor needed – in this snippet of code) and the element #18 will be remembered as being the third (metadata value of 2). In this example metadata is of type size_t the association would be declared as art::Assn<A, B, size_t>. A FindMany query of that association might look like:

art::Handle<std::vector<A>> a_list; // read this from the event

art::FindMany<B, size_t> Query(a_list, event, ModuleLabel);

// search for the last of the objects associated to the third element:
size_t a_index = 2; // this means third element

std::vector<size_t const*> const& metadata = Query.data(a_index);
size_t largest_index = 0, last_item = 0;
for (size_t iB = 0; iB < metadata.size(); ++iB) {
  if (largest_index >= *(metadata[iB])) continue;
  largest_index = *(metadata[iB]);
  last_item = iB;
} // for iB
B const& lastB = Query.at(last_item);

In alternative, the elements and their metadata can be fetched simultaneously with:

std::vector<art::Ptr<B>> const& Bs;
std::vector<size_t const*> const& metadata;

size_t a_index = 2; // this means third element
size_t nMatches = Query.get(a_index, Bs, metadata);

Definition at line 875 of file EVGBAssociationUtil.h.

References art::Assns< L, R, D >::addSingle(), e, and art::ProductRetriever::productGetter().

  {
  
  try{
    // We need the "product ID" of what is going to become a data product.
    // The data product ID is unique for the combination of process, producer,
    // data type and product (instance) label.
    // 
    // we declare here that we want to associate the element first_index of the
    // (only) data product of type std::vector<T> with the other object
    art::ProductID first_id = prod.template getProductID< std::vector<T> >();
    art::Ptr<T> first_ptr(first_id, first_index, evt.productGetter(first_id));
    
    // the same to associate the element second_index of the (only)
    // data product of type std::vector<U> with the first object.
    art::ProductID second_id = prod.template getProductID< std::vector<U> >();
    art::Ptr<U> second_ptr
      (second_id, second_index, evt.productGetter(second_id));
    
    assn.addSingle(first_ptr, second_ptr, data);
  }
  catch(cet::exception &e){
    mf::LogWarning("AssociationUtil")
      << "unable to create requested art:Assns, exception thrown: " << e;
    return false;
  }
  
  return true;
} // evgb::util::CreateAssnD() [01b]

template<class T , class U >

std::vector< const U * > evgb::util::FindUNotAssociatedToT ( art::Handle< U >  b, art::Event const &  evt, std::string const &  label  )

inline

Definition at line 913 of file EVGBAssociationUtil.h.

References fa(), and art::Ptr< T >::get().

Referenced by CreateAssn().

{

  // Do a FindOne for type T for each object of type U
  // If the FindOne returns an invalid maybe ref, add the pointer
  // of object type U to the return vector

  std::vector<const U*> notAssociated;

  art::FindOne<T> fa(b, evt, label);

  for(size_t u = 0; u < b->size(); ++u){
    cet::maybe_ref<T const> t(fa.at(u));
    if( !t.isValid() ){
      art::Ptr<U> ptr(b, u);
      notAssociated.push_back(ptr.get());
    }
  }
//   
  return notAssociated;
}

template<class T , class U >

std::vector< art::Ptr< U > > evgb::util::FindUNotAssociatedToTP ( art::Handle< U >  b, art::Event const &  evt, std::string const &  label  )

inline

Definition at line 938 of file EVGBAssociationUtil.h.

References fa().

Referenced by CreateAssn().

{

  // Do a FindOneP for type T for each object of type U
  // If the FindOne returns an invalid maybe ref, add the pointer
  // of object type U to the return vector

  std::vector< art::Ptr<U> > notAssociated;

  art::FindOneP<T> fa(b, evt, label);

  for(size_t u = 0; u < b->size(); ++u){
    cet::maybe_ref<T const> t(fa.at(u));
    if( !t.isValid() ){
      art::Ptr<U> ptr(b, u);
      notAssociated.push_back(ptr);
    }
  }
  
  return notAssociated;
}

template<class T , class U >

std::vector< std::vector< size_t > > evgb::util::GetAssociatedVectorManyI ( art::Handle< art::Assns< T, U > >  h, art::Handle< std::vector< T > >  index_p  )

inline

Definition at line 982 of file EVGBAssociationUtil.h.

Referenced by CreateAssn().

{
  std::vector< std::vector<size_t> > associated_indices(index_p->size());
  for(auto const& pair : *h)
    associated_indices.at(pair.first.key()).push_back(pair.second.key());
  return associated_indices;
}

template<class T , class U >

std::vector< std::vector< const U * > > evgb::util::GetAssociatedVectorManyP ( art::Handle< art::Assns< T, U > >  h, art::Handle< std::vector< T > >  index_p  )

inline

Definition at line 991 of file EVGBAssociationUtil.h.

Referenced by CreateAssn().

{
  std::vector< std::vector<const U*> > associated_pointers(index_p->size());
  for(auto const& pair : *h)
    associated_pointers.at(pair.first.key()).push_back( &(*(pair.second)) );
  return associated_pointers;
}

template<class T , class U >

std::vector< size_t > evgb::util::GetAssociatedVectorOneI ( art::Handle< art::Assns< T, U > >  h, art::Handle< std::vector< T > >  index_p  )

inline

Definition at line 964 of file EVGBAssociationUtil.h.

Referenced by CreateAssn().

{
  std::vector<size_t> associated_index(index_p->size());
  for(auto const& pair : *h)
    associated_index.at(pair.first.key()) = pair.second.key();
  return associated_index;
}

template<class T , class U >

std::vector< const U * > evgb::util::GetAssociatedVectorOneP ( art::Handle< art::Assns< T, U > >  h, art::Handle< std::vector< T > >  index_p  )

inline

Definition at line 973 of file EVGBAssociationUtil.h.

Referenced by CreateAssn().

{
  std::vector<const U*> associated_pointer(index_p->size());
  for(auto const& pair : *h)
    associated_pointer.at(pair.first.key()) = &(*(pair.second));
  return associated_pointer;
}