Regina Calculation Engine
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Represents a layered loop component of a triangulation. More...
#include <subcomplex/nlayeredloop.h>
Public Member Functions | |
virtual | ~NLayeredLoop () |
Destroys this layered loop. More... | |
NLayeredLoop * | clone () 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... | |
NEdge * | getHinge (int which) const |
Returns the requested hinge edge of this layered loop. More... | |
NManifold * | getManifold () const |
Returns the 3-manifold represented by this triangulation, if such a recognition routine has been implemented. More... | |
NAbelianGroup * | getHomologyH1 () 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... | |
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... | |
Input and Output | |
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 NLayeredLoop * | isLayeredLoop (const NComponent *comp) |
Determines if the given triangulation component is a layered loop. More... | |
static NStandardTriangulation * | isStandardTriangulation (NComponent *component) |
Determines whether the given component represents one of the standard triangulations understood by Regina. More... | |
static NStandardTriangulation * | isStandardTriangulation (NTriangulation *tri) |
Determines whether the given triangulation represents one of the standard triangulations understood by Regina. More... | |
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.
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inlinevirtual |
Destroys this layered loop.
NLayeredLoop* regina::NLayeredLoop::clone | ( | ) | const |
Returns a newly created clone of this structure.
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inherited |
Returns the output from writeTextLong() as a string.
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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.
which | specifies which hinge to return; this must be 0 or 1. |
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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.
Reimplemented from regina::NStandardTriangulation.
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inline |
Returns the length of this layered loop.
See the general class notes for further details.
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inline |
Returns the length of this layered loop.
See the general class notes for further details.
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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.
Reimplemented from regina::NStandardTriangulation.
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inherited |
Returns the name of this specific triangulation as a human-readable string.
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inherited |
Returns the name of this specific triangulation in TeX format.
No leading or trailing dollar signs will be included.
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static |
Determines if the given triangulation component is a layered loop.
comp | the triangulation component to examine. |
null
if the given component is not a layered loop.
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staticinherited |
Determines whether the given component represents one of the standard triangulations understood by Regina.
The list of recognised triangulations is expected to grow between releases.
If the standard triangulation returned has boundary triangles then the given component must have the same corresponding boundary triangles, i.e., the component cannot have any further identifications of these boundary triangles with each other.
Note that the triangulation-based routine isStandardTriangulation(NTriangulation*) may recognise more triangulations than this routine, since passing an entire triangulation allows access to more information.
component | the triangulation component under examination. |
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staticinherited |
Determines whether the given triangulation represents one of the standard triangulations understood by Regina.
The list of recognised triangulations is expected to grow between releases.
If the standard triangulation returned has boundary triangles then the given triangulation must have the same corresponding boundary triangles, i.e., the triangulation cannot have any further identifications of these boundary triangles with each other.
This routine may recognise more triangulations than the component-based isStandardTriangulation(NComponent*), since passing an entire triangulation allows access to more information.
tri | the triangulation under examination. |
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inline |
Determines if this layered loop contains a twist.
See the general class notes for further details.
true
if and only if this layered loop contains a twist.
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inherited |
Returns the output from writeTextShort() as a string.
__str__()
function.
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inlineinherited |
A deprecated alias for str(), which returns the output from writeTextShort() as a string.
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inlineinherited |
A deprecated alias for detail(), which returns the output from writeTextLong() as a string.
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inlinevirtual |
Writes the name of this triangulation as a human-readable string to the given output stream.
out | the output stream to which to write. |
Implements regina::NStandardTriangulation.
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inlinevirtual |
Writes the name of this triangulation in TeX format to the given output stream.
No leading or trailing dollar signs will be included.
out | the output stream to which to write. |
Implements regina::NStandardTriangulation.
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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.
out | the output stream to which to write. |
Reimplemented from regina::ShareableObject.
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inlinevirtualinherited |
Writes this object in short text format to the given output stream.
The output should be human-readable, should fit on a single line, and should not end with a newline.
out | the output stream to which to write. |
Implements regina::ShareableObject.