Regina Calculation Engine
Public Member Functions | Static Public Member Functions | List of all members
regina::NLayeredLoop Class Reference

Represents a layered loop component of a triangulation. More...

#include <subcomplex/nlayeredloop.h>

Inheritance diagram for regina::NLayeredLoop:
regina::NStandardTriangulation regina::ShareableObject regina::boost::noncopyable

Public Member Functions

virtual ~NLayeredLoop ()
 Destroys this layered loop. More...
 
NLayeredLoopclone () const
 Returns a newly created clone of this structure. More...
 
unsigned long getLength () const
 Returns the length of this layered loop. More...
 
unsigned long getIndex () const
 Returns the length of this layered loop. More...
 
bool isTwisted () const
 Determines if this layered loop contains a twist. More...
 
NEdgegetHinge (int which) const
 Returns the requested hinge edge of this layered loop. More...
 
NManifoldgetManifold () const
 Returns the 3-manifold represented by this triangulation, if such a recognition routine has been implemented. More...
 
NAbelianGroupgetHomologyH1 () const
 Returns the expected first homology group of this triangulation, if such a routine has been implemented. More...
 
std::ostream & writeName (std::ostream &out) const
 Writes the name of this triangulation as a human-readable string to the given output stream. More...
 
std::ostream & writeTeXName (std::ostream &out) const
 Writes the name of this triangulation in TeX format to the given output stream. More...
 
void writeTextLong (std::ostream &out) const
 Writes this object in long text format to the given output stream. More...
 
- Public Member Functions inherited from regina::NStandardTriangulation
virtual ~NStandardTriangulation ()
 A destructor that does nothing. More...
 
std::string getName () const
 Returns the name of this specific triangulation as a human-readable string. More...
 
std::string getTeXName () const
 Returns the name of this specific triangulation in TeX format. More...
 
virtual void writeTextShort (std::ostream &out) const
 Writes this object in short text format to the given output stream. More...
 
- Public Member Functions inherited from regina::ShareableObject
 ShareableObject ()
 Default constructor that does nothing. More...
 
virtual ~ShareableObject ()
 Default destructor that does nothing. More...
 
std::string str () const
 Returns the output from writeTextShort() as a string. More...
 
std::string toString () const
 A deprecated alias for str(), which returns the output from writeTextShort() as a string. More...
 
std::string detail () const
 Returns the output from writeTextLong() as a string. More...
 
std::string toStringLong () const
 A deprecated alias for detail(), which returns the output from writeTextLong() as a string. More...
 

Static Public Member Functions

static NLayeredLoopisLayeredLoop (const NComponent *comp)
 Determines if the given triangulation component is a layered loop. More...
 
- Static Public Member Functions inherited from regina::NStandardTriangulation
static NStandardTriangulationisStandardTriangulation (NComponent *component)
 Determines whether the given component represents one of the standard triangulations understood by Regina. More...
 
static NStandardTriangulationisStandardTriangulation (NTriangulation *tri)
 Determines whether the given triangulation represents one of the standard triangulations understood by Regina. More...
 

Additional Inherited Members

- Protected Member Functions inherited from regina::boost::noncopyable
 noncopyable ()
 A constructor which does nothing. More...
 
 ~noncopyable ()
 A destructor which does nothing. More...
 

Detailed Description

Represents a layered loop component of a triangulation.

A layered loop is a layered chain of n tetrahedra whose bottom tetrahedron is layered onto its top tetrahedron to form a complete loop. See the NLayeredChain class notes for a description of a layered chain.

To make a layered chain into a layered loop, the bottom faces of the first tetrahedron will be layered upon the top faces of the last tetrahedron, completing the loop. At this stage there is a choice. The layering can be done in the usual fashion, or there may be a twist in which the upper square (the bottom faces of the first tetrahedron) is rotated 180 degrees before being layered on the lower annulus (the top faces of the last tetrahedron).

If there is a twist, the two hinge edges become identified and the entire component has a single vertex. If there is no twist, the two hinge edges remain distinct (and disjoint) and the entire component has two vertices.

The length of the layered loop is the number of tetrahedra it contains. A layered loop must contain at least one tetrahedron.

All optional NStandardTriangulation routines are implemented for this class.

Test:
Included in the test suite.

Constructor & Destructor Documentation

regina::NLayeredLoop::~NLayeredLoop ( )
inlinevirtual

Destroys this layered loop.

Member Function Documentation

NLayeredLoop* regina::NLayeredLoop::clone ( ) const

Returns a newly created clone of this structure.

Returns
a newly created clone.
NEdge * regina::NLayeredLoop::getHinge ( int  which) const
inline

Returns the requested hinge edge of this layered loop.

See the general class notes for further details. If there is only one hinge but parameter which is 1, null will be returned.

Parameters
whichspecifies which hinge to return; this must be 0 or 1.
Returns
the requested hinge edge.
NAbelianGroup* regina::NLayeredLoop::getHomologyH1 ( ) const
virtual

Returns the expected first homology group of this triangulation, if such a routine has been implemented.

If the calculation of homology has not yet been implemented for this triangulation then this routine will return 0.

This routine does not work by calling NTriangulation::getHomologyH1() on the associated real triangulation. Instead the homology is calculated directly from the known properties of this standard triangulation.

The details of which standard triangulations have homology calculation routines can be found in the notes for the corresponding subclasses of NStandardTriangulation. The default implementation of this routine returns 0.

The homology group will be newly allocated and must be destroyed by the caller of this routine.

If this NStandardTriangulation describes an entire NTriangulation (and not just a part thereof) then the results of this routine should be identical to the homology group obtained by calling NTriangulation::getHomologyH1() upon the associated real triangulation.

Returns
the first homology group of this triangulation, or 0 if the appropriate calculation routine has not yet been implemented.

Reimplemented from regina::NStandardTriangulation.

unsigned long regina::NLayeredLoop::getIndex ( ) const
inline

Returns the length of this layered loop.

See the general class notes for further details.

Deprecated:
The preferred way of accessing the length of a layered loop is through getLength().
Returns
the length of this layered loop.
unsigned long regina::NLayeredLoop::getLength ( ) const
inline

Returns the length of this layered loop.

See the general class notes for further details.

Returns
the length of this layered loop.
NManifold* regina::NLayeredLoop::getManifold ( ) const
virtual

Returns the 3-manifold represented by this triangulation, if such a recognition routine has been implemented.

If the 3-manifold cannot be recognised then this routine will return 0.

The details of which standard triangulations have 3-manifold recognition routines can be found in the notes for the corresponding subclasses of NStandardTriangulation. The default implementation of this routine returns 0.

It is expected that the number of triangulations whose underlying 3-manifolds can be recognised will grow between releases.

The 3-manifold will be newly allocated and must be destroyed by the caller of this routine.

Returns
the underlying 3-manifold.

Reimplemented from regina::NStandardTriangulation.

static NLayeredLoop* regina::NLayeredLoop::isLayeredLoop ( const NComponent comp)
static

Determines if the given triangulation component is a layered loop.

Parameters
compthe triangulation component to examine.
Returns
a newly created structure containing details of the layered loop, or null if the given component is not a layered loop.
bool regina::NLayeredLoop::isTwisted ( ) const
inline

Determines if this layered loop contains a twist.

See the general class notes for further details.

Returns
true if and only if this layered loop contains a twist.
std::ostream & regina::NLayeredLoop::writeName ( std::ostream &  out) const
inlinevirtual

Writes the name of this triangulation as a human-readable string to the given output stream.

Python:
The parameter out does not exist; standard output will be used.
Parameters
outthe output stream to which to write.
Returns
a reference to the given output stream.

Implements regina::NStandardTriangulation.

std::ostream & regina::NLayeredLoop::writeTeXName ( std::ostream &  out) const
inlinevirtual

Writes the name of this triangulation in TeX format to the given output stream.

No leading or trailing dollar signs will be included.

Warning
The behaviour of this routine has changed as of Regina 4.3; in earlier versions, leading and trailing dollar signs were provided.
Python:
The parameter out does not exist; standard output will be used.
Parameters
outthe output stream to which to write.
Returns
a reference to the given output stream.

Implements regina::NStandardTriangulation.

void regina::NLayeredLoop::writeTextLong ( std::ostream &  out) const
inlinevirtual

Writes this object in long text format to the given output stream.

The output should provide the user with all the information they could want. The output should be human-readable, should not contain extremely long lines (so users can read the output in a terminal), and should end with a final newline.

The default implementation of this routine merely calls writeTextShort() and adds a newline.

Python:
The parameter out does not exist; standard output will be used.
Parameters
outthe output stream to which to write.

Reimplemented from regina::ShareableObject.


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

Copyright © 1999-2013, 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).