Regina 7.3 Calculation Engine
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A utility class for searching through all possible gluing permutation sets that correspond to a given tetrahedron face pairing. More...
#include <census/gluingpermsearcher3.h>
Public Member Functions | |
GluingPermSearcher (FacetPairing< 3 > pairing, FacetPairing< 3 >::IsoList autos, bool orientableOnly, bool finiteOnly, CensusPurge whichPurge) | |
Initialises a new search for gluing permutation sets. More... | |
GluingPermSearcher (std::istream &in) | |
Initialises a new search manager based on data read from the given input stream. More... | |
virtual | ~GluingPermSearcher () |
Destroys this search manager and all supporting data structures. More... | |
template<typename Action , typename... Args> | |
void | runSearch (Action &&action, Args &&... args) |
Generates all possible gluing permutation sets that satisfy the current search criteria. More... | |
template<typename Action , typename... Args> | |
void | partialSearch (long maxDepth, Action &&action, Args &&... args) |
Runs a partial search for all possible gluing permutations that satisfy the search criteria, branching only to the given depth and no further. More... | |
bool | isComplete () 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... | |
std::string | taggedData () const |
Returns 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... | |
std::string | data () const |
Returns all internal data in a plain text format. More... | |
void | writeTextShort (std::ostream &out) const |
Writes a short text representation of this object to the given output stream. More... | |
GluingPermSearcher (const GluingPermSearcher &)=delete | |
GluingPermSearcher & | operator= (const GluingPermSearcher &)=delete |
void | writeTextLong (std::ostream &out) const |
A default implementation for detailed output. More... | |
std::string | str () const |
Returns a short text representation of this object. More... | |
std::string | utf8 () const |
Returns a short text representation of this object using unicode characters. More... | |
std::string | detail () const |
Returns a detailed text representation of this object. More... | |
Static Public Member Functions | |
template<typename Action , typename... Args> | |
static void | findAllPerms (FacetPairing< 3 > pairing, FacetPairing< 3 >::IsoList autos, bool orientableOnly, bool finiteOnly, CensusPurge whichPurge, Action &&action, Args &&... args) |
The main entry routine for running a search for all gluing permutation sets that complement a given face pairing. More... | |
static std::unique_ptr< GluingPermSearcher< 3 > > | bestSearcher (FacetPairing< 3 > pairing, FacetPairing< 3 >::IsoList autos, bool orientableOnly, bool finiteOnly, CensusPurge whichPurge) |
Constructs a search manager of the best possible class for the given search parameters. More... | |
static std::unique_ptr< GluingPermSearcher< 3 > > | fromTaggedData (std::istream &in) |
Creates a new search manager based on tagged data read from the given input stream. More... | |
static std::unique_ptr< GluingPermSearcher< 3 > > | fromTaggedData (const std::string &data) |
Creates a new search manager based on tagged data stored in the given string. More... | |
Static Public Attributes | |
static constexpr char | dataTag = 'g' |
A character used to identify this class when reading and writing tagged data in text format. More... | |
Protected Types | |
using | ActionWrapper = std::function< void(const GluingPerms< 3 > &)> |
The type used to hold the user's action function and arguments when enumerating gluing permutations. More... | |
Protected Member Functions | |
virtual void | searchImpl (long maxDepth, ActionWrapper &&action) |
A de-templatised implementation of runSearch() and partialSearch(). More... | |
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 FacetSpec< 3 > &face) const |
Determines whether the permutations already constructed model a triangulation with an edge identified with itself in reverse. More... | |
bool | lowDegreeEdge (const FacetSpec< 3 > &face, bool testDegree12, bool testDegree3) const |
Determines whether the permutations already constructed model a triangulation with a low degree edge. More... | |
virtual char | dataTagInternal () const |
Returns the character used to identify this class when storing tagged data in text format. More... | |
Protected Attributes | |
GluingPerms< 3 > | perms_ |
The set of gluing permutations under construction. More... | |
const FacetPairing< 3 >::IsoList | autos_ |
The set of isomorphisms that define equivalence of gluing permutation sets. 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... | |
CensusPurge | whichPurge_ |
Are there any types of triangulation that we may optionally avoid constructing? This should be a bitwise OR of constants from the CensusPurgeFlags enumeration. 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... | |
FacetSpec< 3 > * | order |
Describes the order in which gluing permutations are assigned to faces. More... | |
size_t | orderSize |
The total number of edges in the face pairing graph, i.e., the number of elements of interest in the order[] array. More... | |
ssize_t | orderElt |
Marks which element of order[] we are currently examining at this stage of the search. More... | |
A utility class for searching through all possible gluing permutation sets that correspond to a given tetrahedron face pairing.
Subclasses of GluingPermSearcher<3> correspond to specialised (and heavily optimised) search algorithms that may be used in sufficiently constrained scenarios. The main class GluingPermSearcher<3> 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).
This class is designed to manage the construction of a large census of triangulations, and so it does not support copying, moving or swapping.
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The type used to hold the user's action function and arguments when enumerating gluing permutations.
regina::GluingPermSearcher< 3 >::GluingPermSearcher | ( | FacetPairing< 3 > | pairing, |
FacetPairing< 3 >::IsoList | autos, | ||
bool | orientableOnly, | ||
bool | finiteOnly, | ||
CensusPurge | whichPurge | ||
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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.
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().
pairing | the specific pairing of tetrahedron faces that the generated permutation sets will complement. |
autos | the 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 (which you can generate via pairing.findAutomorphisms() ). |
orientableOnly | true if only gluing permutations corresponding to orientable triangulations should be generated, or false if no such restriction should be imposed. |
finiteOnly | true 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. |
whichPurge | specifies which permutation sets we may avoid constructing (see the function notes above for details). This should be a bitwise OR of constants from the CensusPurgeFlags enumeration, or PURGE_NONE 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. |
regina::GluingPermSearcher< 3 >::GluingPermSearcher | ( | std::istream & | in | ) |
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 fromTaggedData() instead.
InvalidInput | The data found in the input stream is invalid, incomplete, or incorrectly formatted. |
in | the input stream from which to read. |
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virtual |
Destroys this search manager and all supporting data structures.
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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.
face | the specific tetrahedron face upon which tests will be based. |
true
if the permutations under construction will lead to an edge identified with itself in reverse, or false
if no such edge is found.
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inlinestatic |
Constructs a search manager of the best possible class for the given search parameters.
Different subclasses of GluingPermSearcher<3> 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.
See the GluingPermSearcher<3> constructor for documentation on the arguments to this routine.
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Returns all internal data in a plain text format.
This object can be recreated from this text data by calling the input stream constructor for the appropriate class.
This routine may be useful for transferring objects from one processor to another.
If subclasses override this function, they should write subclass data after superclass data. This means it is safe to dump data from a subclass and then recreate a new superclass object from that data (though subclass-specific information will be lost).
This routine returns the same information that dumpData() writes.
The key difference between data() and taggedData() is that taggedData() preserves all internal information even if this object belongs to a subclass of GluingPermSearcher, whereas data() only writes information pertaining to this base class.
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inlineprotectedvirtual |
Returns the character used to identify this class when storing tagged data in text format.
Reimplemented in regina::EulerSearcher, regina::CompactSearcher, regina::ClosedPrimeMinSearcher, and regina::HyperbolicMinSearcher.
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inherited |
Returns a detailed text representation of this object.
This text may span many lines, and should provide the user with all the information they could want. It should be human-readable, should not contain extremely long lines (which cause problems for users reading the output in a terminal), and should end with a final newline. There are no restrictions on the underlying character set.
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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 the appropriate class.
This routine may be useful for transferring objects from one processor to another.
If subclasses override this function, they should write subclass data after superclass data. This means it is safe to dump data from a subclass and then recreate a new superclass object from that data (though subclass-specific information will be lost).
This routine outputs the same information that data() returns.
The key difference between dumpData() and dumpTaggedData() is that dumpTaggedData() preserves all internal information even if this object belongs to a subclass of GluingPermSearcher, whereas dumpData() only writes information pertaining to this base class.
out | the output stream to which the data should be written. |
Reimplemented in regina::EulerSearcher, regina::CompactSearcher, regina::ClosedPrimeMinSearcher, and regina::HyperbolicMinSearcher.
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inline |
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 fromTaggedData() to transport objects from place to place whose precise class is unknown.
This routine outputs the same information that taggedData() returns.
The key difference between dumpData() and dumpTaggedData() is that dumpTaggedData() preserves all internal information even if this object belongs to a subclass of GluingPermSearcher, whereas dumpData() only writes information pertaining to this base class.
out | the output stream to which the data should be written. |
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inlinestatic |
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 GluingPermSearcher<3> and then calls runSearch().
See the GluingPermSearcher<3> constructor for documentation on the arguments to this routine. See the runSearch() method for documentation on how the search runs and returns its results via action and args..
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inlinestatic |
Creates a new search manager based on tagged data stored in the given string.
This may be a new search or a partially completed search.
The tagged data should be in the format returned by taggedData(). 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.
InvalidArgument | The data found in the given string is invalid, incomplete, or incorrectly formatted. |
data | the tagged data from which to reconstruct a search manager. |
null
if the data in the given string was invalid or incorrectly formatted.
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inlinestatic |
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.
InvalidInput | The data found in the given input stream is invalid, incomplete, or incorrectly formatted. |
in | the input stream from which to read. |
null
if the data in the input stream was invalid or incorrectly formatted.
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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).
true
if the current set is in canonical form, or false
otherwise.
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Determines whether this search manager holds a complete gluing permutation set or just a partially completed search state.
This may assist the action routine when running partial depth-based searches. See partialSearch() for further details.
true
if a complete gluing permutation set is held, or false
otherwise.
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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.
face | the specific tetrahedron face upon which tests will be based. |
testDegree12 | true if we should test for non-boundary edges of degree 1 or 2. |
testDegree3 | true if we should test for non-boundary edges of degree 3 involving three distinct tetrahedra. |
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.
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Runs a partial search for all possible gluing permutations that satisfy the search criteria, branching only to the given depth and no further.
This routine essentially does some but not all of the work of runSearch(). See the runSearch() documentation for a detailed overview of what the full search aims to achieve.
If runSearch() enumerates an entire search tree, then you can think of partialSearch() as only enumerating the first maxDepth levels of this search tree. Rather than producing complete gluing permutation sets, this search will produce a series of partially-constructed permutation sets. A partial search can be continued by calling runSearch() again on the underlying GluingPermSearcher (perhaps after being frozen, or passed on to a different processor via taggedData() and fromTaggedData()). If necessary, the action routine may call isComplete() 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.
If the search tree is shallow enough (or if maxDepth is large enough), it is possible that this routine will produce complete gluing permutation sets.
maxDepth | the depth of the partial search to run. A negative number indicates that a full search should be run. |
action | a function (or other callable object) to call for each permutation set (partial or complete) that is found. |
args | any additional arguments that should be passed to action, following the initial permutation set argument. |
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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, this routine will call action (which must be a function or some other callable object).
void
.It is possible to run only a partial search, branching to a given depth but no further; for this you should use the separate routine partialSearch(), not runSearch().
action | a function (or other callable object) to call for each permutation set that is found. |
args | any additional arguments that should be passed to action, following the initial permutation set argument. |
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protectedvirtual |
A de-templatised implementation of runSearch() and partialSearch().
Here the templated action plus arguments are bundled together in a wrapper whose full type is known in advance.
Subclasses corresponding to more specialised search criteria should override this routine to use a better optimised algorithm where possible.
See runSearch() and partialSearch() for further details.
Reimplemented in regina::EulerSearcher, regina::CompactSearcher, regina::ClosedPrimeMinSearcher, and regina::HyperbolicMinSearcher.
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inherited |
Returns a short text representation of this object.
This text should be human-readable, should use plain ASCII characters where possible, and should not contain any newlines.
Within these limits, this short text ouptut should be as information-rich as possible, since in most cases this forms the basis for the Python __str__()
and __repr__()
functions.
__str__()
will use precisely this function, and for most classes the Python __repr__()
function will incorporate this into its output.
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inline |
Returns 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 fromTaggedData() to transport objects from place to place whose precise class is unknown.
This routine returns the same information that dumpTaggedData() writes.
The key difference between data() and taggedData() is that taggedData() preserves all internal information even if this object belongs to a subclass of GluingPermSearcher, whereas data() only writes information pertaining to this base class.
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inherited |
Returns a short text representation of this object using unicode characters.
Like str(), this text should be human-readable, should not contain any newlines, and (within these constraints) should be as information-rich as is reasonable.
Unlike str(), this function may use unicode characters to make the output more pleasant to read. The string that is returned will be encoded in UTF-8.
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inlineinherited |
A default implementation for detailed output.
This routine simply calls T::writeTextShort() and appends a final newline.
out | the output stream to which to write. |
void regina::GluingPermSearcher< 3 >::writeTextShort | ( | std::ostream & | out | ) | const |
Writes a short text representation of this object to the given output stream.
out | the output stream to which to write. |
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The set of isomorphisms that define equivalence of gluing permutation sets.
Generally this is the set of all automorphisms of the underlying face pairing.
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staticconstexpr |
A character used to identify this class when reading and writing tagged data in text format.
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Are we only searching for gluing permutations that correspond to finite triangulations?
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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 ClosedPrimeMinSearcher for examples).
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Marks which element of order[] we are currently examining at this stage of the search.
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The total number of edges in the face pairing graph, i.e., the number of elements of interest in the order[] array.
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Are we only searching for gluing permutations that correspond to orientable triangulations?
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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.
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The set of gluing permutations under construction.
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Has the search started yet? This helps distinguish between a new search and the resumption of a partially completed search.
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Are there any types of triangulation that we may optionally avoid constructing? This should be a bitwise OR of constants from the CensusPurgeFlags enumeration.
See the constructor documentation for further details on this search parameter.