Regina Calculation Engine
Public Member Functions | Static Public Member Functions
regina::NLayeredChainPair Class Reference

Represents a layered chain pair component of a triangulation. More...

#include <subcomplex/nlayeredchainpair.h>

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

List of all members.

Public Member Functions

virtual ~NLayeredChainPair ()
 Destroys this layered chain pair.
NLayeredChainPairclone () const
 Returns a newly created clone of this structure.
const NLayeredChaingetChain (int which) const
 Returns the requested layered chain used to form this structure.
NManifoldgetManifold () const
 Returns the 3-manifold represented by this triangulation, if such a recognition routine has been implemented.
NAbelianGroupgetHomologyH1 () const
 Returns the expected first homology group of this triangulation, if such a routine has been implemented.
std::ostream & writeName (std::ostream &out) const
 Writes the name of this triangulation as a human-readable string to the given output stream.
std::ostream & writeTeXName (std::ostream &out) const
 Writes the name of this triangulation in TeX format to the given output stream.
void writeTextLong (std::ostream &out) const
 Writes this object in long text format to the given output stream.

Static Public Member Functions

static NLayeredChainPairisLayeredChainPair (const NComponent *comp)
 Determines if the given triangulation component is a layered chain pair.

Detailed Description

Represents a layered chain pair component of a triangulation.

A layered chain pair consists of two layered chains (as described by class NLayeredChain) glued together in a particular way.

Orient the hinge edges and diagonals of each chain so they all point in the same direction around the solid tori formed by each layered chain (a diagonal is an edge between the two top faces or an edge between the two bottom faces of a layered chain).

The two top faces of the first chain are glued to a top and bottom face of the second chain, and the two bottom faces of the first chain are glued to a top and bottom face of the second chain.

The four oriented diagonals are all identified as a single edge. Of the remaining unglued edges (two hinge edges and two non-hinge edges per chain), each hinge edge of one chain must be identified to a non-hinge edge of the other chain and vice versa. From here the face identifications are uniquely determined.

Note that a layered chain pair in which one of the chains contains only one tetrahedron is in fact a layered loop with a twist (see class NLayeredLoop).

All optional NStandardTriangulation routines are implemented for this class.


Constructor & Destructor Documentation

regina::NLayeredChainPair::~NLayeredChainPair ( ) [inline, virtual]

Destroys this layered chain pair.


Member Function Documentation

NLayeredChainPair* regina::NLayeredChainPair::clone ( ) const

Returns a newly created clone of this structure.

Returns:
a newly created clone.
const NLayeredChain * regina::NLayeredChainPair::getChain ( int  which) const [inline]

Returns the requested layered chain used to form this structure.

If the two chains have different lengths, the shorter chain will be chain 0 and the longer chain will be chain 1.

Parameters:
whichspecifies which chain to return; this must be 0 or 1.
Returns:
the requested layered chain.
NAbelianGroup* regina::NLayeredChainPair::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.

NManifold* regina::NLayeredChainPair::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 NLayeredChainPair* regina::NLayeredChainPair::isLayeredChainPair ( const NComponent comp) [static]

Determines if the given triangulation component is a layered chain pair.

Parameters:
compthe triangulation component to examine.
Returns:
a newly created structure containing details of the layered chain pair, or null if the given component is not a layered chain pair.
std::ostream & regina::NLayeredChainPair::writeName ( std::ostream &  out) const [inline, virtual]

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::NLayeredChainPair::writeTeXName ( std::ostream &  out) const [inline, virtual]

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::NLayeredChainPair::writeTextLong ( std::ostream &  out) const [inline, virtual]

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

The output should provided the user with all the information they could want. The output should end with a 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 © 1999-2011, The Regina development team
This software is released under the GNU General Public License.
For further information, or to submit a bug or other problem, please contact Ben Burton (bab@debian.org).