MC::Loops< Evt, Prt, Vtx > Class Template Reference

#include <Loops.h>

Collaboration diagram for MC::Loops< Evt, Prt, Vtx >:

Public Member Functions
	Loops ()
	Default constructor. More...
	Loops (const Evt *evt)
	Constructor passing the event; immediately index the event that is passed. More...
bool	isLoop (const Prt &p) const
	Is this particle in a loop? More...
bool	isLoop (const Vtx &v) const
	Is this vertex in a loop? More...
const std::vector< Prt > &	loop_particles () const
	Accessor: return the full list of particles in loops. More...
const std::vector< Vtx > &	loop_vertices () const
	Accessor: return the full list of vertices in loops. More...
int	findLoops (const Evt *evt, bool force)
	Function that does the work to identify loops Pass the event of interest. More...

Private Attributes
const Evt *	m_evt = nullptr
	Local pointer to the event passed in the constructor or most recent call to findLoops. More...
std::vector< Prt >	m_loop_particles
	List of all particles in m_evt that are in loops. More...
std::vector< Vtx >	m_loop_vertices
	List of all vertices in m_evt that are in loops. More...

Detailed Description

template<class Evt, class Prt, class Vtx>
class MC::Loops< Evt, Prt, Vtx >

Definition at line 14 of file Loops.h.

Constructor & Destructor Documentation

Loops() [1/2]

template<class Evt , class Prt , class Vtx >

MC::Loops< Evt, Prt, Vtx >::Loops ( )

inline

Default constructor.

Definition at line 18 of file Loops.h.

{}

Loops() [2/2]

template<class Evt , class Prt , class Vtx >

MC::Loops< Evt, Prt, Vtx >::Loops ( const Evt *  evt )

inline

Constructor passing the event; immediately index the event that is passed.

Definition at line 21 of file Loops.h.

                          {
        findLoops(evt,true);
    }

Member Function Documentation

findLoops()

template<class Evt , class Prt , class Vtx >

int MC::Loops< Evt, Prt, Vtx >::findLoops ( const Evt *  evt, bool  force  )

inline

Function that does the work to identify loops Pass the event of interest.

'force' allows the event to be re-searched even if it was previously.

Definition at line 47 of file Loops.h.

                                              {
        // If the event is empty, return -1 (an error code, basically)
        if (!evt) return -1;
        // If we have already indexed the event and are not forced to do it again, return
        if (evt == m_evt &&  !force) return 0;
 
        // Update the local event pointer. This is now the most recent event that has been indexed.
        m_evt = evt;
        // Clear the lists of particles and vertices. These will now refer to this event.
        m_loop_particles.clear();
        m_loop_vertices.clear();
 
        // Create a map, keeping track of whether particles are in loops.
        // 0 for "unknown", 1 for "in a loop", -1 for "not in a loop"
        std::map<Prt, int> incycle;
 
        // Easiest case to deal with: if a particle has no production or end vertex, it is not in a loop
        for (const auto & p: *m_evt){
            if (!p->end_vertex()||!p->production_vertex()){
              incycle[p] = -1;
            } else {
              incycle[p] = 0;
            }
        }
 
        // Now begin interating through particles to try to find loops
        size_t minincycle = m_evt->particles_size();
        for (;;) {
            // Number of particles still unknown in the current iteration
            size_t unknown = 0;
            for (const auto & p: *m_evt) {
 
                // If the particle was already identified as in/not in a loop, skip it
                if (incycle[p] != 0) continue;
                // Otherwise it is unknown on this iteration
                unknown++;
 
                // Start from the end vertex of the particle
                auto ev = p->end_vertex();
                if (ev) {
                    // If the end vertex of a particle exclusively has particles not in loops
                    // then this particle cannot be in a loop either
                    bool goodo = true;
                    for (auto& po: *ev) goodo = goodo && (incycle[po] == -1);
                    if (goodo) incycle[p] = -1;
                }
 
                // Now start from the production vertex of the particle
                auto pv = p->production_vertex();
                if (pv) {
                    // If the production vertex of a particle exclusively has particles not
                    // in loops, then this particle cannot be in a loop either
                    bool goodi = true;
#ifdef HEPMC3
                    for (auto& pi: ev->particles_in()) goodi = goodi && (incycle[pi] == -1);
#else
                    for (auto ip = ev->particles_in_const_begin();
                         ip != ev->particles_in_const_end();
                         ++ip)
                    {
                      goodi = goodi && (incycle[*ip] == -1);
                    }
#endif
                    if (goodi) incycle[p] = -1;
                }
            }
            // If the number of unknown particles has not changed, we are done iterating
            if (minincycle == unknown) break;
            // If the number of unknown particles has changed, update at iterate again
            minincycle = std::min(minincycle, unknown);
        } // Outer loop - iterate until all particles have been dealt with
 
        // Any remaining particles that have not been identified are a part of a loop
        // Add them to our list of looping particles
        for (const auto & p: *m_evt){
          if (incycle[p] == 0) incycle[p] = 1;
          if (incycle[p] == 1) m_loop_particles.push_back(p);
        }
 
        // Now loop over all vertices.
#ifdef HEPMC3
        for (auto & v: m_evt->vertices()) {
#else
        for (auto iv = m_evt->vertices_begin(); iv != m_evt->vertices_end(); ++iv) {
            auto v = *iv;
#endif
            bool push = false;
            // First check incoming particles.
            // If any incoming are in loops, consider this vertex to be in a loop.
#ifdef HEPMC3
            for ( auto& pin: v->particles_in()){
                if (incycle[pin] == 1) {
#else
            for ( auto ipin = v->particles_in_const_begin();
                  ipin != v->particles_in_const_end();
                  ++ipin){
                if (incycle[*ipin] == 1) {
#endif
                      push = true;
                      break;
                }
            } // End of loop over incoming particles
            // In case we have not yet identified the vertex as being in a loop
            // then check the outgoing particles from the vertex.
            // If any outgoing are in loops, consider this vertex to be in a loop.
            if(!push) {
                for ( const auto& pou: *v) {
                    if (incycle[pou] == 1) {
                        push = true;
                        break;
                    }
                }
            }
            // Update the records if this vertex is in a loop.
            if (push) m_loop_vertices.push_back(v);
        } // End of loop over vertices
 
        // All finished. Return success.
        return 0;
    } // End of the findLoops function

isLoop() [1/2]

template<class Evt , class Prt , class Vtx >

bool MC::Loops< Evt, Prt, Vtx >::isLoop ( const Prt &  p ) const

inline

Is this particle in a loop?

Definition at line 26 of file Loops.h.

                                    {
        return std::find(m_loop_particles.begin(), m_loop_particles.end(), p) != m_loop_particles.end();
    }

isLoop() [2/2]

template<class Evt , class Prt , class Vtx >

bool MC::Loops< Evt, Prt, Vtx >::isLoop ( const Vtx &  v ) const

inline

Is this vertex in a loop?

Definition at line 31 of file Loops.h.

                                    {
        return std::find(m_loop_vertices.begin(), m_loop_vertices.end(), v) != m_loop_vertices.end();
    }

loop_particles()

template<class Evt , class Prt , class Vtx >

const std::vector<Prt>& MC::Loops< Evt, Prt, Vtx >::loop_particles ( ) const

inline

Accessor: return the full list of particles in loops.

Definition at line 36 of file Loops.h.

                                                 {
        return m_loop_particles;
    }

loop_vertices()

template<class Evt , class Prt , class Vtx >

const std::vector<Vtx>& MC::Loops< Evt, Prt, Vtx >::loop_vertices ( ) const

inline

Accessor: return the full list of vertices in loops.

Definition at line 41 of file Loops.h.

                                                {
        return m_loop_vertices;
    }

Member Data Documentation

m_evt

template<class Evt , class Prt , class Vtx >

const Evt* MC::Loops< Evt, Prt, Vtx >::m_evt = nullptr

private

Local pointer to the event passed in the constructor or most recent call to findLoops.

Definition at line 171 of file Loops.h.

m_loop_particles

template<class Evt , class Prt , class Vtx >

std::vector<Prt> MC::Loops< Evt, Prt, Vtx >::m_loop_particles

private

List of all particles in m_evt that are in loops.

Definition at line 174 of file Loops.h.

m_loop_vertices

template<class Evt , class Prt , class Vtx >

std::vector<Vtx> MC::Loops< Evt, Prt, Vtx >::m_loop_vertices

private

List of all vertices in m_evt that are in loops.

Definition at line 177 of file Loops.h.

---

The documentation for this class was generated from the following file:

• Loops.h