Regina Calculation Engine
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regina::NGluingPermSearcher Class Reference

A utility class for searching through all possible gluing permutation sets that correspond to a given tetrahedron face pairing. More...

#include <census/ngluingpermsearcher.h>

Inheritance diagram for regina::NGluingPermSearcher:
regina::NGluingPerms regina::NGenericGluingPerms< 3 > regina::NCompactSearcher regina::NEulerSearcher regina::NClosedPrimeMinSearcher regina::NHyperbolicMinSearcher

Public Types

enum  PurgeFlags {
  PURGE_NONE = 0, PURGE_NON_MINIMAL = 1, PURGE_NON_PRIME = 2, PURGE_NON_MINIMAL_PRIME = 3,
  PURGE_NON_MINIMAL_HYP = 9, PURGE_P2_REDUCIBLE = 4
}
 Flags to indicate that our enumeration may (at the discretion of the enumeration algorithm) ignore certain classes of triangulations. More...
 
typedef DimTraits< dim >
::FacetPairing 
FacetPairing
 
typedef DimTraits< dim >::Perm Perm
 
typedef DimTraits< dim >::Simplex Simplex
 
typedef DimTraits< dim >
::Triangulation 
Triangulation
 

Public Member Functions

 NGluingPermSearcher (const NFacePairing *pairing, const NFacePairing::IsoList *autos, bool orientableOnly, bool finiteOnly, int whichPurge, UseGluingPerms use, void *useArgs=0)
 Initialises a new search for gluing permutation sets. More...
 
 NGluingPermSearcher (std::istream &in, UseGluingPerms use, void *useArgs=0)
 Initialises a new search manager based on data read from the given input stream. More...
 
virtual ~NGluingPermSearcher ()
 Destroys this search manager and all supporting data structures. More...
 
virtual void runSearch (long maxDepth=-1)
 Generates all possible gluing permutation sets that satisfy the current search criteria. More...
 
bool completePermSet () const
 Determines whether this search manager holds a complete gluing permutation set or just a partially completed search state. More...
 
void dumpTaggedData (std::ostream &out) const
 Dumps all internal data in a plain text format, along with a marker to signify which precise class the data belongs to. More...
 
virtual void dumpData (std::ostream &out) const
 Dumps all internal data in a plain text format to the given output stream. More...
 
unsigned getNumberOfTetrahedra () const
 Returns the total number of tetrahedra under consideration. More...
 
const NFacePairinggetFacePairing () const
 Returns the specific pairing of tetrahedron faces that this set of gluing permutations complements. More...
 
bool inputError () const
 Was an error found during construction from an input stream? More...
 
unsigned size () const
 Returns the total number of simplices under consideration. More...
 
const FacetPairing * getFacetPairing () const
 Returns the specific pairing of simplex facets that this set of gluing permutations complements. More...
 
Perm gluingPerm (const NFacetSpec< dim > &source) const
 Returns the gluing permutation associated with the given simplex facet. More...
 
Perm gluingPerm (unsigned simp, unsigned facet) const
 Returns the gluing permutation associated with the given simplex facet. More...
 
Triangulation * triangulate () const
 Returns a newly created triangulation as modelled by this set of gluing permutations and the associated simplex facet pairing. More...
 

Static Public Member Functions

static void findAllPerms (const NFacePairing *pairing, const NFacePairing::IsoList *autos, bool orientableOnly, bool finiteOnly, int whichPurge, UseGluingPerms use, void *useArgs=0)
 The main entry routine for running a search for all gluing permutation sets that complement a given face pairing. More...
 
static NGluingPermSearcherbestSearcher (const NFacePairing *pairing, const NFacePairing::IsoList *autos, bool orientableOnly, bool finiteOnly, int whichPurge, UseGluingPerms use, void *useArgs=0)
 Constructs a search manager of the best possible class for the given search parameters. More...
 
static NGluingPermSearcherreadTaggedData (std::istream &in, UseGluingPerms use, void *useArgs=0)
 Creates a new search manager based on tagged data read from the given input stream. More...
 

Static Public Attributes

static const char dataTag_
 A character used to identify this class when reading and writing tagged data in text format. More...
 

Protected Member Functions

bool isCanonical () const
 Compares the current set of gluing permutations with its preimage under each automorphism of the underlying face pairing, in order to see whether the current set is in canonical form (i.e., is lexicographically smallest). More...
 
bool badEdgeLink (const NTetFace &face) const
 Determines whether the permutations already constructed model a triangulation with an edge identified with itself in reverse. More...
 
bool lowDegreeEdge (const NTetFace &face, bool testDegree12, bool testDegree3) const
 Determines whether the permutations already constructed model a triangulation with a low degree edge. More...
 
virtual char dataTag () const
 Returns the character used to identify this class when storing tagged data in text format. More...
 
int & permIndex (const NFacetSpec< dim > &source)
 Returns the index into array Perm::Sn_1 describing how the the given facet is joined to its partner. More...
 
int & permIndex (unsigned simp, unsigned facet)
 Returns the index into array Perm::Sn_1 describing how the the given facet is joined to its partner. More...
 
const int & permIndex (const NFacetSpec< dim > &source) const
 Returns the index into array Perm::Sn_1 describing how the the given facet is joined to its partner. More...
 
const int & permIndex (unsigned simp, unsigned facet) const
 Returns the index into array Perm::Sn_1 describing how the the given facet is joined to its partner. More...
 
int gluingToIndex (const NFacetSpec< dim > &source, const Perm &gluing) const
 Returns the index into array Perm::Sn_1 corresponding to the given gluing permutation from the given facet to its partner. More...
 
int gluingToIndex (unsigned simp, unsigned facet, const Perm &gluing) const
 Returns the index into array Perm::Sn_1 corresponding to the given gluing permutation from the given facet to its partner. More...
 
Perm indexToGluing (const NFacetSpec< dim > &source, int index) const
 Returns the gluing permutation from the given facet to its partner that corresponds to the given index into array Perm::Sn_1. More...
 
Perm indexToGluing (unsigned simp, unsigned facet, int index) const
 Returns the gluing permutation from the given facet to its partner that corresponds to the given index into array Perm::Sn_1. More...
 

Protected Attributes

const NFacePairing::IsoListautos_
 The set of isomorphisms that define equivalence of gluing permutation sets. More...
 
bool autosNew
 Did we create the isomorphism list autos_ ourselves (in which case we must destroy it also)? More...
 
bool orientableOnly_
 Are we only searching for gluing permutations that correspond to orientable triangulations? More...
 
bool finiteOnly_
 Are we only searching for gluing permutations that correspond to finite triangulations? More...
 
int whichPurge_
 Are there any types of triangulation that we may optionally avoid constructing? This should be a bitwise OR of constants from the PurgeFlags enumeration. More...
 
UseGluingPerms use_
 A routine to call each time a gluing permutation set is found during the search. More...
 
void * useArgs_
 Additional user-supplied data to be passed as the second argument to the use_ routine. More...
 
bool started
 Has the search started yet? This helps distinguish between a new search and the resumption of a partially completed search. More...
 
int * orientation
 Keeps track of the orientation of each tetrahedron in the underlying triangulation. More...
 
NTetFaceorder
 Describes the order in which gluing permutations are assigned to faces. More...
 
int orderSize
 The total number of edges in the face pairing graph, i.e., the number of elements of interest in the order[] array. More...
 
int orderElt
 Marks which element of order[] we are currently examining at this stage of the search. More...
 
const FacetPairing * pairing_
 The facet pairing that this permutation set complements. More...
 
int * permIndices_
 The index into array Perm::Sn_1 describing how each simplex facet is glued to its partner. More...
 
bool inputError_
 Has an error occurred during construction from an input stream? More...
 

Detailed Description

A utility class for searching through all possible gluing permutation sets that correspond to a given tetrahedron face pairing.

Subclasses of NGluingPermSearcher correspond to specialised (and heavily optimised) search algorithms that may be used in sufficiently constrained scenarios. The main class NGluingPermSearcher offers a default (but slower) search algorithm that may be used in more general contexts.

The simplest way of performing a search through all possible gluing permutations is by calling the static method findAllPerms(). This will examine the search parameters and ensure that the best possible algorithm is used. For finer control over the program flow, the static method bestSearcher() can be used to create a search manager of the most suitable class and then runSearch() can be called on this object directly. For absolute control, a specific algorithm can be forced by explicitly constructing an object of the corresponding class (and again calling runSearch() on that object directly).

Note that this class derives from NGluingPerms. The search will involve building and repeatedly modifying the inherited NGluingPerms data in-place.

Python:
Only the PurgeFlags enumeration from this class is present, and the PurgeFlags constants are also made directly available through the regina namespace. Therefore there is no need to explicitly access the NGluingPermSearcher through Python.

Constructor & Destructor Documentation

regina::NGluingPermSearcher::NGluingPermSearcher ( const NFacePairing pairing,
const NFacePairing::IsoList autos,
bool  orientableOnly,
bool  finiteOnly,
int  whichPurge,
UseGluingPerms  use,
void *  useArgs = 0 
)

Initialises a new search for gluing permutation sets.

The search is started by calling runSearch(). Note that the static method findAllPerms() handles both construction and searching, and is the preferred entry point for end users.

The arguments to this constructor describe the search parameters in detail, as well as what should be done with each gluing permutation set that is found.

Parameter whichPurge may be used to avoid constructing permutation sets that correspond to triangulations satisfying certain constraints (such as non-minimality). The use of this parameter, combined with parameters orientableOnly and finiteOnly, can significantly speed up the permutation set generation. For some combinations of these parameters entirely different algorithms are used.

Note that not all permutation sets described by parameter whichPurge will be avoided (i.e., you may get gluing permutation sets that you did not want). It is guaranteed however that every permutation set whose corresonding triangulation does not satisfy the whichPurge constraints will be generated.

Similarly, even if finiteOnly is set to true, some non-finite triangulations might still slip through the net (since the full vertex links are not always constructed). However, like whichPurge, setting finiteOnly to true allow the census algorithm to take shortcuts and therefore run faster. The resulting triangulations may be tested for finiteness (and other properties) by calling triangulate().

Precondition
The given face pairing is connected, i.e., it is possible to reach any tetrahedron from any other tetrahedron via a series of matched face pairs.
The given face pairing is in canonical form as described by NFacePairing::isCanonical(). Note that all face pairings constructed by NFacePairing::findAllPairings() are of this form.
Parameters
pairingthe specific pairing of tetrahedron faces that the generated permutation sets will complement.
autosthe collection of isomorphisms that define equivalence of permutation sets. These are used by runSearch(), which produces each permutation set precisely once up to equivalence. These isomorphisms must all be automorphisms of the given face pairing, and will generally be the set of all such automorphisms. This parameter may be 0, in which case the set of all automorphisms of the given face pairing will be generated and used.
orientableOnlytrue if only gluing permutations corresponding to orientable triangulations should be generated, or false if no such restriction should be imposed.
finiteOnlytrue if only gluing permutations corresponding to finite triangulations are required, or false if there is no such requirement. Note that regardless of this value, some non-finite triangulations might still be produced; see the notes above for details.
whichPurgespecifies which permutation sets we may avoid constructing (see the function notes above for details). This should be a bitwise OR of constants from the PurgeFlags enumeration, or 0 if we should simply generate every possible permutation set. If a variety of purge constants are bitwise ORed together, a permutation set whose triangulation satisfies any of these constraints may be avoided. Note that not all such permutation sets will be avoided, but enough are avoided that the performance increase is noticeable.
usethe function to call upon each permutation set that is found. The first parameter passed to this function will be a gluing permutation set. The second parameter will be parameter useArgs as was passed to this routine.
useArgsthe pointer to pass as the final parameter for the function use which will be called upon each permutation set found.
regina::NGluingPermSearcher::NGluingPermSearcher ( std::istream &  in,
UseGluingPerms  use,
void *  useArgs = 0 
)

Initialises a new search manager based on data read from the given input stream.

This may be a new search or a partially completed search.

This routine reads data in the format written by dumpData(). If you wish to read data whose precise class is unknown, consider using dumpTaggedData() and readTaggedData() instead.

If the data found in the input stream is invalid or incorrectly formatted, the routine inputError() will return true but the contents of this object will be otherwise undefined.

Warning
The data format is liable to change between Regina releases. Data in this format should be used on a short-term temporary basis only.
Parameters
inthe input stream from which to read.
useas for the main NGluingPermSearcher constructor.
useArgsas for the main NGluingPermSearcher constructor.
virtual regina::NGluingPermSearcher::~NGluingPermSearcher ( )
virtual

Destroys this search manager and all supporting data structures.

Member Function Documentation

bool regina::NGluingPermSearcher::badEdgeLink ( const NTetFace face) const
protected

Determines whether the permutations already constructed model a triangulation with an edge identified with itself in reverse.

Note that such edges can only occur in non-orientable triangulations.

Tests that do not refer to the gluing permutation for the given face will not be run.

This routine is not fussy about the order in which gluing permutations are selected, as long as permutations not yet selected have the corresponding element of permIndices[] set to -1.

If finiteOnly_ is true in the search criteria, additional tests will be run that can eliminate triangulations with non-orientable vertex links. Although these tests are not searching for bad edge links per se, they can be performed within this routine with very little additional work needing to be done.

Parameters
facethe specific tetrahedron face upon which tests will be based.
Returns
true if the permutations under construction will lead to an edge identified with itself in reverse, or false if no such edge is found.
static NGluingPermSearcher* regina::NGluingPermSearcher::bestSearcher ( const NFacePairing pairing,
const NFacePairing::IsoList autos,
bool  orientableOnly,
bool  finiteOnly,
int  whichPurge,
UseGluingPerms  use,
void *  useArgs = 0 
)
static

Constructs a search manager of the best possible class for the given search parameters.

Different subclasses of NGluingPermSearcher provide optimised search algorithms for different types of search.

Calling this routine and then calling runSearch() on the result has the same effect as the all-in-one routine findAllPerms(). Unless you have specialised requirements (such as partial searching), you are probably better calling findAllPerms() instead.

The resulting object is newly created, and must be destroyed by the caller of this routine.

See the NGluingPermSearcher constructor for documentation on the arguments to this routine.

Precondition
The given face pairing is connected, i.e., it is possible to reach any tetrahedron from any other tetrahedron via a series of matched face pairs.
The given face pairing is in canonical form as described by NFacePairing::isCanonical(). Note that all face pairings constructed by NFacePairing::findAllPairings() are of this form.
Returns
the newly created search manager.
bool regina::NGluingPermSearcher::completePermSet ( ) const
inline

Determines whether this search manager holds a complete gluing permutation set or just a partially completed search state.

This may assist the use_ routine when running partial depth-based searches. See runSearch() for further details.

Returns
true if a complete gluing permutation set is held, or false otherwise.
char regina::NGluingPermSearcher::dataTag ( ) const
inlineprotectedvirtual

Returns the character used to identify this class when storing tagged data in text format.

Returns
the class tag.

Reimplemented in regina::NHyperbolicMinSearcher, regina::NClosedPrimeMinSearcher, regina::NCompactSearcher, and regina::NEulerSearcher.

virtual void regina::NGluingPermSearcher::dumpData ( std::ostream &  out) const
virtual

Dumps all internal data in a plain text format to the given output stream.

This object can be recreated from this text data by calling the input stream constructor for this class.

This routine may be useful for transferring objects from one processor to another.

Note that subclass data is written after superclass data, so it is safe to dump data from a subclass and then recreate a new superclass object from that data (though subclass-specific information will of course be lost).

Warning
The data format is liable to change between Regina releases. Data in this format should be used on a short-term temporary basis only.
Parameters
outthe output stream to which the data should be written.

Reimplemented from regina::NGenericGluingPerms< 3 >.

Reimplemented in regina::NHyperbolicMinSearcher, regina::NClosedPrimeMinSearcher, regina::NCompactSearcher, and regina::NEulerSearcher.

void regina::NGluingPermSearcher::dumpTaggedData ( std::ostream &  out) const

Dumps all internal data in a plain text format, along with a marker to signify which precise class the data belongs to.

This routine can be used with readTaggedData() to transport objects from place to place whose precise class is unknown.

Warning
The data format is liable to change between Regina releases. Data in this format should be used on a short-term temporary basis only.
Parameters
outthe output stream to which the data should be written.
static void regina::NGluingPermSearcher::findAllPerms ( const NFacePairing pairing,
const NFacePairing::IsoList autos,
bool  orientableOnly,
bool  finiteOnly,
int  whichPurge,
UseGluingPerms  use,
void *  useArgs = 0 
)
static

The main entry routine for running a search for all gluing permutation sets that complement a given face pairing.

This routine examines the search parameters, chooses the best possible search algorithm, constructs an object of the corresponding subclass of NGluingPermSearcher and then calls runSearch().

See the NGluingPermSearcher constructor for documentation on the arguments to this routine. See the runSearch() method for documentation on how the search runs and returns its results.

Precondition
The given face pairing is connected, i.e., it is possible to reach any tetrahedron from any other tetrahedron via a series of matched face pairs.
The given face pairing is in canonical form as described by NFacePairing::isCanonical(). Note that all face pairings constructed by NFacePairing::findAllPairings() are of this form.
const NFacePairing * regina::NGluingPerms::getFacePairing ( ) const
inlineinherited

Returns the specific pairing of tetrahedron faces that this set of gluing permutations complements.

Deprecated:
This routine has been renamed to getFacetPairing(). This old name has been kept for backward compatibility, but will be removed in some future version of Regina.
Returns
the corresponding tetrahedron face pairing.
const FacetPairing* regina::NGenericGluingPerms< dim >::getFacetPairing ( ) const
inherited

Returns the specific pairing of simplex facets that this set of gluing permutations complements.

Returns
the corresponding simplex facet pairing.
unsigned regina::NGluingPerms::getNumberOfTetrahedra ( ) const
inlineinherited

Returns the total number of tetrahedra under consideration.

Deprecated:
This routine has been renamed to size(). This old name has been kept for backward compatibility, but will be removed in some future version of Regina.
Returns
the number of tetrahedra under consideration.
Perm regina::NGenericGluingPerms< dim >::gluingPerm ( const NFacetSpec< dim > &  source) const
inherited

Returns the gluing permutation associated with the given simplex facet.

Precondition
The given facet is actually paired with some other facet in the underlying pairwise matching (see routine getFacetPairing()).
The given facet is a real simplex facet (not boundary, before-the-start or past-the-end).
Parameters
sourcethe simplex facet under investigation.
Returns
the associated gluing permutation.
Perm regina::NGenericGluingPerms< dim >::gluingPerm ( unsigned  simp,
unsigned  facet 
) const
inherited

Returns the gluing permutation associated with the given simplex facet.

Precondition
The given facet is actually paired with some other facet in the underlying pairwise matching (see routine getFacetPairing()).
Parameters
simpthe simplex under investigation (this must be strictly less than the total number of simplices under consideration).
facetthe facet of the given simplex under investigation (between 0 and dim inclusive).
Returns
the associated gluing permutation.
int regina::NGenericGluingPerms< dim >::gluingToIndex ( const NFacetSpec< dim > &  source,
const Perm &  gluing 
) const
protectedinherited

Returns the index into array Perm::Sn_1 corresponding to the given gluing permutation from the given facet to its partner.

This need not be the index into Perm::Sn_1 that is currently stored for the given facet.

Indices into array Perm::Sn_1 are stored internally in the array permIndices_. Full gluing permutations on the other hand are used in constructing triangulations.

Precondition
The given simplex facet has a partner according to the underlying facet pairing, i.e., is not a boundary facet.
If the given simplex facet and its partner are facets x and y of their respective simplices, then the given gluing permutation maps x to y.
Parameters
sourcethe simplex facet under investigation.
gluinga possible gluing permutation from the given simplex facet to its partner according to the underlying facet pairing.
Returns
the index into Perm::Sn_1 corresponding to the given gluing permutation; this will be between 0 and dim!-1 inclusive.
int regina::NGenericGluingPerms< dim >::gluingToIndex ( unsigned  simp,
unsigned  facet,
const Perm &  gluing 
) const
protectedinherited

Returns the index into array Perm::Sn_1 corresponding to the given gluing permutation from the given facet to its partner.

This need not be the index into Perm::Sn_1 that is currently stored for the given facet.

Indices into array Perm::Sn_1 are stored internally in the array permIndices_. Full gluing permutations on the other hand are used in constructing triangulations.

Precondition
The given simplex facet has a partner according to the underlying facet pairing, i.e., is not a boundary facet.
If the given simplex facet and its partner are facets x and y of their respective simplices, then the given gluing permutation maps x to y.
Parameters
simpthe simplex under investigation; this must be strictly less than the total number of simplices under consideration.
facetthe facet of the given simplex under investigation; this must be between 0 and dim inclusive.
gluinga possible gluing permutation from the given simplex facet to its partner according to the underlying facet pairing.
Returns
the index into Perm::Sn_1 corresponding to the given gluing permutation; this will be between 0 and dim!-1 inclusive.
Perm regina::NGenericGluingPerms< dim >::indexToGluing ( const NFacetSpec< dim > &  source,
int  index 
) const
protectedinherited

Returns the gluing permutation from the given facet to its partner that corresponds to the given index into array Perm::Sn_1.

This index into Perm::Sn_1 need not be the index that is currently stored for the given facet.

Indices into array Perm::Sn_1 are stored internally in the array permIndices_. Full gluing permutations on the other hand are used in constructing triangulations.

If the given simplex facet and its partner according to the underlying facet pairing are facets x and y of their respective simplices, then the resulting gluing permutation will map x to y.

Precondition
The given simplex facet has a partner according to the underlying facet pairing, i.e., is not a boundary facet.
Parameters
sourcethe simplex facet under investigation.
indexan index into Perm::Sn_1; this must be between 0 and dim!-1 inclusive.
Returns
the gluing permutation corresponding to the given index into Perm::Sn_1.
Perm regina::NGenericGluingPerms< dim >::indexToGluing ( unsigned  simp,
unsigned  facet,
int  index 
) const
protectedinherited

Returns the gluing permutation from the given facet to its partner that corresponds to the given index into array Perm::Sn_1.

This index into Perm::Sn_1 need not be the index that is currently stored for the given facet.

Indices into array Perm::Sn_1 are stored internally in the array permIndices_. Full gluing permutations on the other hand are used in constructing triangulations.

If the given simplex facet and its partner according to the underlying facet pairing are facets x and y of their respective simplices, then the resulting gluing permutation will map x to y.

Precondition
The given simplex facet has a partner according to the underlying facet pairing, i.e., is not a boundary facet.
Parameters
simpthe simplex under investigation; this must be strictly less than the total number of simplices under consideration.
facetthe facet of the given simplex under investigation; this must be between 0 and dim inclusive.
indexan index into Perm::Sn_1; this must be between 0 and dim!-1 inclusive.
Returns
the gluing permutation corresponding to the given index into Perm::Sn_1.
bool regina::NGenericGluingPerms< dim >::inputError ( ) const
inherited

Was an error found during construction from an input stream?

This routine returns true if an input stream constructor was used to create this object but the data in the input stream was invalid or incorrectly formatted.

If a different constructor was called (i.e., no input stream was used), then this routine will always return false.

Returns
true if an error occurred during construction from an input stream, or false otherwise.
bool regina::NGluingPermSearcher::isCanonical ( ) const
protected

Compares the current set of gluing permutations with its preimage under each automorphism of the underlying face pairing, in order to see whether the current set is in canonical form (i.e., is lexicographically smallest).

Returns
true if the current set is in canonical form, or false otherwise.
bool regina::NGluingPermSearcher::lowDegreeEdge ( const NTetFace face,
bool  testDegree12,
bool  testDegree3 
) const
protected

Determines whether the permutations already constructed model a triangulation with a low degree edge.

Precisely which types of low degree edges are identified must be specified through parameters testDegree12 and testDegree3.

Tests that do not refer to the gluing permutation for the given face will not be run.

This routine is not fussy about the order in which gluing permutations are selected, as long as permutations not yet selected have the corresponding element of permIndices[] set to -1.

Parameters
facethe specific tetrahedron face upon which tests will be based.
testDegree12true if we should test for non-boundary edges of degree 1 or 2.
testDegree3true if we should test for non-boundary edges of degree 3 involving three distinct tetrahedra.
Returns
true if the permutations under construction will lead to a low-degree edge as specified by parameters testDegree12 and testDegree3, or false if no such edge is found.
int& regina::NGenericGluingPerms< dim >::permIndex ( const NFacetSpec< dim > &  source)
protectedinherited

Returns the index into array Perm::Sn_1 describing how the the given facet is joined to its partner.

Note that this permutation is not a gluing permutation as such, but rather a permutation of 0,...,dim-1 only. For a real facet gluing permutation, see routine gluingPerm().

Precondition
The given facet is a real simplex facet (not boundary, before-the-start or past-the-end).
Parameters
sourcethe simplex facet under investigation.
Returns
a reference to the corresponding array index.
int& regina::NGenericGluingPerms< dim >::permIndex ( unsigned  simp,
unsigned  facet 
)
protectedinherited

Returns the index into array Perm::Sn_1 describing how the the given facet is joined to its partner.

Note that this permutation is not a gluing permutation as such, but rather a permutation of 0,...,dim-1 only. For a real facet gluing permutation, see routine gluingPerm().

Parameters
simpthe simplex under investigation (this must be strictly less than the total number of simplices under consideration).
facetthe facet of the given simplex under investigation (between 0 and dim inclusive).
Returns
a reference to the corresponding array index.
const int& regina::NGenericGluingPerms< dim >::permIndex ( const NFacetSpec< dim > &  source) const
protectedinherited

Returns the index into array Perm::Sn_1 describing how the the given facet is joined to its partner.

Note that this permutation is not a gluing permutation as such, but rather a permutation of 0,...,dim-1 only. For a real facet gluing permutation, see routine gluingPerm().

Precondition
The given facet is a real simplex facet (not boundary, before-the-start or past-the-end).
Parameters
sourcethe simplex facet under investigation.
Returns
a reference to the corresponding array index.
const int& regina::NGenericGluingPerms< dim >::permIndex ( unsigned  simp,
unsigned  facet 
) const
protectedinherited

Returns the index into array Perm::Sn_1 describing how the the given facet is joined to its partner.

Note that this permutation is not a gluing permutation as such, but rather a permutation of 0,...,dim-1 only. For a real facet gluing permutation, see routine gluingPerm().

Parameters
simpthe simplex under investigation (this must be strictly less than the total number of simplices under consideration).
facetthe facet of the given simplex under investigation (between 0 and dim inclusive).
Returns
a reference to the corresponding array index.
static NGluingPermSearcher* regina::NGluingPermSearcher::readTaggedData ( std::istream &  in,
UseGluingPerms  use,
void *  useArgs = 0 
)
static

Creates a new search manager based on tagged data read from the given input stream.

This may be a new search or a partially completed search.

The tagged data should be in the format written by dumpTaggedData(). The precise class of the search manager will be determined from the tagged data, and does not need to be known in advance. This is in contrast to dumpData() and the input stream constructors, where the class of the data being read must be known at compile time.

If the data found in the input stream is invalid or incorrectly formatted, a null pointer will be returned. Otherwise a newly constructed search manager will be returned, and it is the responsibility of the caller of this routine to destroy it after use.

The arguments use and useArgs are the same as for the NGluingPermSearcher constructor.

Warning
The data format is liable to change between Regina releases. Data in this format should be used on a short-term temporary basis only.
Parameters
inthe input stream from which to read.
virtual void regina::NGluingPermSearcher::runSearch ( long  maxDepth = -1)
virtual

Generates all possible gluing permutation sets that satisfy the current search criteria.

The search criteria are specified in the class constructor, or through the static method findAllPerms().

Each set of gluing permutations will be produced precisely once up to equivalence, where equivalence is defined by the given set of automorphisms of the given face pairing.

For each permutation set that is generated, routine use_ (as passed to the class constructor) will be called with that permutation set as an argument.

Once the generation of permutation sets has finished, routine use_ will be called once more, this time with null as its first (permutation set) argument.

Subclasses corresponding to more specialised search criteria should override this routine to use a better optimised algorithm where possible.

It is possible to run only a partial search, branching to a given depth but no further. In this case, rather than producing complete gluing permutation sets, the search will produce a series of partially-complete NGluingPermSearcher objects. These partial searches may then be restarted by calling runSearch() once more (usually after being frozen or passed on to a different processor). If necessary, the use_ routine may call completePermSet() to distinguish between a complete set of gluing permutations and a partial search state.

Note that a restarted search will never drop below its initial depth. That is, calling runSearch() with a fixed depth can be used to subdivide the overall search space into many branches, and then calling runSearch() on each resulting partial search will complete each of these branches without overlap.

Todo:
Feature: Allow cancellation of permutation set generation.
Parameters
maxDepththe depth of the partial search to run, or a negative number if a full search should be run (the default).

Reimplemented in regina::NHyperbolicMinSearcher, regina::NClosedPrimeMinSearcher, regina::NCompactSearcher, and regina::NEulerSearcher.

unsigned regina::NGenericGluingPerms< dim >::size ( ) const
inherited

Returns the total number of simplices under consideration.

Returns
the number of simplices under consideration.
Triangulation* regina::NGenericGluingPerms< dim >::triangulate ( ) const
inherited

Returns a newly created triangulation as modelled by this set of gluing permutations and the associated simplex facet pairing.

Each matched pair of facets and their associated permutations will be realised as two simplex facets in the triangulation glued together with the corresponding gluing permutation. Each unmatched facet will be realised as a boundary facet in the triangulation.

It is the responsibility of the caller of this routine to delete this triangulation once it is no longer required.

Returns
a newly created triangulation modelled by this structure.

Member Data Documentation

const NFacePairing::IsoList* regina::NGluingPermSearcher::autos_
protected

The set of isomorphisms that define equivalence of gluing permutation sets.

Generally this is the set of all automorphisms of the underlying face pairing.

bool regina::NGluingPermSearcher::autosNew
protected

Did we create the isomorphism list autos_ ourselves (in which case we must destroy it also)?

const char regina::NGluingPermSearcher::dataTag_
static

A character used to identify this class when reading and writing tagged data in text format.

bool regina::NGluingPermSearcher::finiteOnly_
protected

Are we only searching for gluing permutations that correspond to finite triangulations?

bool regina::NGenericGluingPerms< dim >::inputError_
protectedinherited

Has an error occurred during construction from an input stream?

NTetFace* regina::NGluingPermSearcher::order
protected

Describes the order in which gluing permutations are assigned to faces.

Specifically, this order is order[0], order[1], ..., order[orderSize-1].

Note that each element of this array corresponds to a single edge of the underlying face pairing graph, which in turn represents a tetrahedron face and its image under the given face pairing.

The specific tetrahedron face stored in this array for each edge of the underlying face pairing graph will be the smaller of the two identified tetrahedron faces (unless otherwise specified for a particular edge type; see NClosedPrimeMinSearcher for examples).

int regina::NGluingPermSearcher::orderElt
protected

Marks which element of order[] we are currently examining at this stage of the search.

int regina::NGluingPermSearcher::orderSize
protected

The total number of edges in the face pairing graph, i.e., the number of elements of interest in the order[] array.

bool regina::NGluingPermSearcher::orientableOnly_
protected

Are we only searching for gluing permutations that correspond to orientable triangulations?

int* regina::NGluingPermSearcher::orientation
protected

Keeps track of the orientation of each tetrahedron in the underlying triangulation.

Orientation is positive/negative, or 0 if unknown. Note that in some algorithms the orientation is simply +/-1, and in some algorithms the orientation counts forwards or backwards from 0 according to how many times the orientation has been set or verified.

const FacetPairing* regina::NGenericGluingPerms< dim >::pairing_
protectedinherited

The facet pairing that this permutation set complements.

This is guaranteed to be the minimal representative of its facet pairing isomorphism class.

int* regina::NGenericGluingPerms< dim >::permIndices_
protectedinherited

The index into array Perm::Sn_1 describing how each simplex facet is glued to its partner.

Note that this is not a gluing permutation as such but rather a permutation of 0,...,dim-1 only (see the routines gluingToIndex() and indexToGluing() for conversions). If a permutation has not yet been selected (e.g., if this permutation set is still under construction) then this index is -1.

bool regina::NGluingPermSearcher::started
protected

Has the search started yet? This helps distinguish between a new search and the resumption of a partially completed search.

UseGluingPerms regina::NGluingPermSearcher::use_
protected

A routine to call each time a gluing permutation set is found during the search.

void* regina::NGluingPermSearcher::useArgs_
protected

Additional user-supplied data to be passed as the second argument to the use_ routine.

int regina::NGluingPermSearcher::whichPurge_
protected

Are there any types of triangulation that we may optionally avoid constructing? This should be a bitwise OR of constants from the PurgeFlags enumeration.

See the constructor documentation for further details on this search parameter.


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

Copyright © 1999-2014, The Regina development team
This software is released under the GNU General Public License, with some additional permissions; see the source code for details.
For further information, or to submit a bug or other problem, please contact Ben Burton (bab@debian.org).