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Gudhi::skeleton_blocker::Skeleton_blocker_complex< SkeletonBlockerDS > Class Template Reference

Abstract Simplicial Complex represented with a skeleton/blockers pair. More...

#include <include/gudhi/Skeleton_blocker_complex.h>

Public Types

typedef SkeletonBlockerDS::Graph_vertex Graph_vertex
 The type of stored vertex node, specified by the template SkeletonBlockerDS.
 
typedef SkeletonBlockerDS::Graph_edge Graph_edge
 The type of stored edge node, specified by the template SkeletonBlockerDS.
 
typedef SkeletonBlockerDS::Vertex_handle Vertex_handle
 The type of an handle to a vertex of the complex.
 
typedef Skeleton_blocker_simplex< Vertex_handleSimplex
 A ordered set of integers that represents a simplex.
 
typedef SimplexBlocker_handle
 Handle to a blocker of the complex.
 
typedef boost::graph_traits< Graph >::edge_descriptor Edge_handle
 Handle to an edge of the complex.
 

Public Member Functions

Vertices operations
Vertex_handle operator[] (Root_vertex_handle global) const
 Return a local Vertex_handle of a vertex given a global one. More...
 
Graph_vertexoperator[] (Vertex_handle address)
 Return the vertex node associated to local Vertex_handle. More...
 
const Graph_vertexoperator[] (Vertex_handle address) const
 Return the vertex node associated to local Vertex_handle. More...
 
Vertex_handle add_vertex ()
 Adds a vertex to the simplicial complex and returns its Vertex_handle. More...
 
void remove_vertex (Vertex_handle address)
 Remove a vertex from the simplicial complex. More...
 
bool contains_vertex (Vertex_handle u) const
 
bool contains_vertex (Root_vertex_handle u) const
 
bool contains_vertices (const Simplex &sigma) const
 
virtual boost::optional< Vertex_handleget_address (Root_vertex_handle id) const
 Given an Id return the address of the vertex having this Id in the complex. More...
 
Root_vertex_handle get_id (Vertex_handle local) const
 
Vertex_handle convert_handle_from_another_complex (const Skeleton_blocker_complex &other, Vertex_handle vh_in_other) const
 Convert an address of a vertex of a complex to the address in the current complex. More...
 
int degree (Vertex_handle local) const
 return the graph degree of a vertex.
 
Edges operations
boost::optional< Edge_handleoperator[] (const std::pair< Vertex_handle, Vertex_handle > &ab) const
 return an edge handle if the two vertices forms an edge in the complex
 
Graph_edgeoperator[] (Edge_handle edge_handle)
 returns the stored node associated to an edge
 
const Graph_edgeoperator[] (Edge_handle edge_handle) const
 returns the stored node associated to an edge
 
Vertex_handle first_vertex (Edge_handle edge_handle) const
 returns the first vertex of an edge More...
 
Vertex_handle second_vertex (Edge_handle edge_handle) const
 returns the first vertex of an edge More...
 
Simplex get_vertices (Edge_handle edge_handle) const
 returns the simplex made with the two vertices of the edge More...
 
Edge_handle add_edge (Vertex_handle a, Vertex_handle b)
 Adds an edge between vertices a and b. More...
 
void add_edge (const Simplex &s)
 Adds all edges of s in the complex.
 
Edge_handle add_edge_without_blockers (Vertex_handle a, Vertex_handle b)
 Adds an edge between vertices a and b without blockers. More...
 
void add_edge_without_blockers (Simplex s)
 Adds all edges of s in the complex without adding blockers.
 
virtual Edge_handle remove_edge (Vertex_handle a, Vertex_handle b)
 Removes an edge from the simplicial complex and all its cofaces. More...
 
void remove_edge (Edge_handle edge)
 Removes edge and its cofaces from the simplicial complex.
 
void keep_only_vertices ()
 The complex is reduced to its set of vertices. All the edges and blockers are removed.
 
bool contains_edge (Vertex_handle a, Vertex_handle b) const
 
bool contains_edges (const Simplex &sigma) const
 
Print and IO methods
std::string to_string () const
 
std::string vertices_to_string () const
 
std::string edges_to_string () const
 
std::string blockers_to_string () const
 

Simplification operations

enum  simplifiable_status
 
enum  contractible_status
 
bool is_popable_blocker (Blocker_handle sigma) const
 
void remove_popable_blockers ()
 
void remove_popable_blockers (Vertex_handle v)
 
void remove_all_popable_blockers (Vertex_handle v)
 Removes all the popable blockers of the complex passing through v and delete them. Also remove popable blockers in the neighborhood if they became popable. More...
 
void remove_star (Vertex_handle v)
 
void remove_star (Vertex_handle a, Vertex_handle b)
 
void remove_star (Edge_handle e)
 
void remove_star (const Simplex &sigma)
 
void add_simplex (const Simplex &sigma)
 add a simplex and all its faces. More...
 
simplifiable_status is_remove_star_homotopy_preserving (const Simplex &simplex)
 
virtual contractible_status is_contractible () const
 Test if the complex is reducible using a strategy defined in the class (by default it tests if the complex is a cone) More...
 

Blockers operations

typedef Skeleton_blocker_link_complex< Skeleton_blocker_complexLink_complex
 
Blocker_handle add_blocker (const Simplex &blocker)
 Adds the simplex to the set of blockers and returns a Blocker_handle toward it if was not present before and 0 otherwise.
 
void remove_blocker (const Blocker_handle sigma)
 Removes the simplex from the set of blockers. More...
 
void remove_blockers ()
 Remove all blockers, in other words, it expand the simplicial complex to the smallest flag complex that contains it.
 
void delete_blocker (Blocker_handle sigma)
 
bool contains_blocker (const Blocker_handle s) const
 
bool contains_blocker (const Simplex &s) const
 
Link_complex link (Vertex_handle v) const
 
Link_complex link (Edge_handle edge) const
 
Link_complex link (const Simplex &simplex) const
 
boost::optional< Simplexget_simplex_address (const Root_simplex_handle &s) const
 Compute the local vertices of 's' in the current complex If one of them is not present in the complex then the return value is uninitialized. More...
 
Root_simplex_handle get_id (const Simplex &local_simplex) const
 returns a simplex with vertices which are the id of vertices of the argument.
 
virtual bool contains (const Simplex &s) const
 returns true iff the simplex s belongs to the simplicial complex.
 
bool empty () const
 
int num_vertices () const
 
int num_edges () const
 
int num_triangles () const
 
size_t num_simplices () const
 
size_t num_simplices (int dimension) const
 
size_t num_blockers () const
 
bool complete () const
 
int num_connected_components () const
 returns the number of connected components in the graph of the 1-skeleton.
 
bool is_cone () const
 Test if the complex is a cone. More...
 

Vertex iterators

typedef Vertex_iterator< Skeleton_blocker_complexComplex_vertex_iterator
 
typedef boost::iterator_range< Complex_vertex_iteratorComplex_vertex_range
 
typedef Neighbors_vertices_iterator< Skeleton_blocker_complexComplex_neighbors_vertices_iterator
 
typedef boost::iterator_range< Complex_neighbors_vertices_iterator > Complex_neighbors_vertices_range
 
Complex_vertex_range vertex_range () const
 Returns a Complex_vertex_range over all vertices of the complex.
 
Complex_neighbors_vertices_range vertex_range (Vertex_handle v) const
 Returns a Complex_edge_range over all edges of the simplicial complex that passes through v.
 

Edge iterators

typedef Edge_iterator< Skeleton_blocker_complexComplex_edge_iterator
 
typedef boost::iterator_range< Complex_edge_iteratorComplex_edge_range
 
typedef Edge_around_vertex_iterator< Skeleton_blocker_complexComplex_edge_around_vertex_iterator
 
typedef boost::iterator_range< Complex_edge_around_vertex_iterator > Complex_edge_around_vertex_range
 
Complex_edge_range edge_range () const
 Returns a Complex_edge_range over all edges of the simplicial complex.
 
Complex_edge_around_vertex_range edge_range (Vertex_handle v) const
 Returns a Complex_edge_range over all edges of the simplicial complex that passes through 'v'.
 

Triangles iterators

typedef Triangle_around_vertex_iterator< Skeleton_blocker_complex, Superior_linkSuperior_triangle_around_vertex_iterator
 
typedef boost::iterator_range< Triangle_around_vertex_iterator< Skeleton_blocker_complex, Link > > Complex_triangle_around_vertex_range
 
typedef boost::iterator_range< Triangle_iterator< Skeleton_blocker_complex > > Complex_triangle_range
 
typedef Triangle_iterator< Skeleton_blocker_complexComplex_triangle_iterator
 
Complex_triangle_around_vertex_range triangle_range (Vertex_handle v) const
 Range over triangles around a vertex of the simplicial complex. Methods .begin() and .end() return a Triangle_around_vertex_iterator. More...
 
Complex_triangle_range triangle_range () const
 Range over triangles of the simplicial complex. Methods .begin() and .end() return a Triangle_around_vertex_iterator. More...
 

Simplices iterators

typedef Simplex_around_vertex_iterator< Skeleton_blocker_complex, LinkComplex_simplex_around_vertex_iterator
 
typedef boost::iterator_range< Complex_simplex_around_vertex_iteratorComplex_simplex_around_vertex_range
 Range over the simplices of the simplicial complex around a vertex. Methods .begin() and .end() return a Complex_simplex_around_vertex_iterator.
 
typedef Simplex_coboundary_iterator< Skeleton_blocker_complex, LinkComplex_simplex_coboundary_iterator
 
typedef boost::iterator_range< Complex_simplex_coboundary_iteratorComplex_coboundary_range
 Range over the simplices of the coboundary of a simplex. Methods .begin() and .end() return a Complex_simplex_coboundary_iterator.
 
typedef Simplex_iterator< Skeleton_blocker_complexComplex_simplex_iterator
 
typedef boost::iterator_range< Complex_simplex_iterator > Complex_simplex_range
 
Complex_simplex_around_vertex_range star_simplex_range (Vertex_handle v) const
 Returns a Complex_simplex_around_vertex_range over all the simplices around a vertex of the complex.
 
Complex_coboundary_range coboundary_range (const Simplex &s) const
 Returns a Complex_simplex_coboundary_iterator over the simplices of the coboundary of a simplex.
 
Complex_simplex_range complex_simplex_range () const
 Returns a Complex_simplex_range over all the simplices of the complex.
 

Constructors, Destructors

 Skeleton_blocker_complex (size_t num_vertices_=0, Visitor *visitor_=NULL)
 constructs a simplicial complex with a given number of vertices and a visitor.
 
template<typename SimpleHandleOutputIterator >
 Skeleton_blocker_complex (SimpleHandleOutputIterator simplices_begin, SimpleHandleOutputIterator simplices_end, bool is_flag_complex=false, Visitor *visitor_=NULL)
 Constructor with a list of simplices. More...
 
 Skeleton_blocker_complex (const Skeleton_blocker_complex &copy)
 
Skeleton_blocker_complexoperator= (const Skeleton_blocker_complex &copy)
 
bool operator== (const Skeleton_blocker_complex &other) const
 
bool operator!= (const Skeleton_blocker_complex &other) const
 
virtual ~Skeleton_blocker_complex ()
 
virtual void clear ()
 
void set_visitor (Visitor *other_visitor)
 allows to change the visitor.
 

Blockers iterators

Complex_blocker_around_vertex_range blocker_range (Vertex_handle v)
 Returns a range of the blockers of the complex passing through a vertex.
 
Const_complex_blocker_around_vertex_range const_blocker_range (Vertex_handle v) const
 Returns a range of the blockers of the complex passing through a vertex.
 
Complex_blocker_range blocker_range ()
 Returns a range of the blockers of the complex.
 
Const_complex_blocker_range const_blocker_range () const
 Returns a range of the blockers of the complex.
 

Edge contraction operations

bool link_condition (Vertex_handle a, Vertex_handle b, bool ignore_popable_blockers=false) const
 
bool link_condition (Edge_handle e, bool ignore_popable_blockers=false) const
 
void contract_edge (Edge_handle edge)
 
void contract_edge (Vertex_handle a, Vertex_handle b)
 

Detailed Description

template<class SkeletonBlockerDS>
class Gudhi::skeleton_blocker::Skeleton_blocker_complex< SkeletonBlockerDS >

Abstract Simplicial Complex represented with a skeleton/blockers pair.

Examples
Skeleton_blocker_from_simplices.cpp, Skeleton_blocker_iteration.cpp, and Skeleton_blocker_link.cpp.

Constructor & Destructor Documentation

◆ Skeleton_blocker_complex()

template<class SkeletonBlockerDS >
template<typename SimpleHandleOutputIterator >
Gudhi::skeleton_blocker::Skeleton_blocker_complex< SkeletonBlockerDS >::Skeleton_blocker_complex ( SimpleHandleOutputIterator  simplices_begin,
SimpleHandleOutputIterator  simplices_end,
bool  is_flag_complex = false,
Visitor visitor_ = NULL 
)
inline

Constructor with a list of simplices.

is_flag_complex indicates if the complex is a flag complex or not (to know if blockers have to be computed or not).

◆ ~Skeleton_blocker_complex()

The destructor delete all blockers allocated.

Member Function Documentation

◆ add_edge()

Adds an edge between vertices a and b.

For instance, the complex contains edge 01 and 12, then calling add_edge with vertex 0 and 2 will create a complex containing the edges 01, 12, 20 but not the triangle 012 (and hence this complex will contains a blocker 012).

◆ add_edge_without_blockers()

Adds an edge between vertices a and b without blockers.

For instance, the complex contains edge 01 and 12, then calling add_edge with vertex 0 and 2 will create a complex containing the triangle 012.

◆ add_simplex()

template<typename SkeletonBlockerDS >
void Gudhi::skeleton_blocker::Skeleton_blocker_complex< SkeletonBlockerDS >::add_simplex ( const Simplex sigma)

add a simplex and all its faces.

the simplex must have dimension greater than one (otherwise use add_vertex or add_edge_without_blockers).

◆ add_vertex()

Adds a vertex to the simplicial complex and returns its Vertex_handle.

Remarks
Vertex representation is contiguous.

◆ clear()

template<class SkeletonBlockerDS >
virtual void Gudhi::skeleton_blocker::Skeleton_blocker_complex< SkeletonBlockerDS >::clear ( )
inlinevirtual

Clears the simplicial complex. After a call to this function, blockers are destroyed. The 1-skeleton and the set of blockers are both empty.

Reimplemented in Gudhi::skeleton_blocker::Skeleton_blocker_sub_complex< ComplexType >.

◆ contains_blocker() [1/2]

template<class SkeletonBlockerDS >
bool Gudhi::skeleton_blocker::Skeleton_blocker_complex< SkeletonBlockerDS >::contains_blocker ( const Blocker_handle  s) const
inline
Returns
true iff s is a blocker of the simplicial complex

◆ contains_blocker() [2/2]

template<class SkeletonBlockerDS >
bool Gudhi::skeleton_blocker::Skeleton_blocker_complex< SkeletonBlockerDS >::contains_blocker ( const Simplex s) const
inline
Returns
true iff s is a blocker of the simplicial complex

◆ contains_edge()

template<class SkeletonBlockerDS >
bool Gudhi::skeleton_blocker::Skeleton_blocker_complex< SkeletonBlockerDS >::contains_edge ( Vertex_handle  a,
Vertex_handle  b 
) const
inline
Returns
true iff the simplicial complex contains an edge between vertices a and b

◆ contains_edges()

template<class SkeletonBlockerDS >
bool Gudhi::skeleton_blocker::Skeleton_blocker_complex< SkeletonBlockerDS >::contains_edges ( const Simplex sigma) const
inline
Returns
true iff the simplicial complex contains all vertices and all edges of simplex sigma

◆ contains_vertices()

template<class SkeletonBlockerDS >
bool Gudhi::skeleton_blocker::Skeleton_blocker_complex< SkeletonBlockerDS >::contains_vertices ( const Simplex sigma) const
inline
Returns
true iff the simplicial complex contains all vertices of simplex sigma

◆ contract_edge() [1/2]

Contracts the edge.

Remarks
If the link condition Link(ab) = Link(a) inter Link(b) is not satisfied, it removes first all blockers passing through 'ab'

◆ contract_edge() [2/2]

Contracts the edge connecting vertices a and b.

Remarks
If the link condition Link(ab) = Link(a) inter Link(b) is not satisfied, it removes first all blockers passing through 'ab'

◆ convert_handle_from_another_complex()

template<class SkeletonBlockerDS >
Vertex_handle Gudhi::skeleton_blocker::Skeleton_blocker_complex< SkeletonBlockerDS >::convert_handle_from_another_complex ( const Skeleton_blocker_complex< SkeletonBlockerDS > &  other,
Vertex_handle  vh_in_other 
) const
inline

Convert an address of a vertex of a complex to the address in the current complex.

If the current complex is a sub (or sup) complex of 'other', it converts the address of a vertex v expressed in 'other' to the address of the vertex v in the current one.

Remarks
this methods uses Root_vertex_handle to identify the vertex and assumes the vertex is present in the current complex.

◆ delete_blocker()

Removes the simplex sigma from the set of blockers and deallocate sigma.

◆ first_vertex()

returns the first vertex of an edge

it assumes that the edge is present in the complex

◆ get_address()

template<class SkeletonBlockerDS >
virtual boost::optional< Vertex_handle > Gudhi::skeleton_blocker::Skeleton_blocker_complex< SkeletonBlockerDS >::get_address ( Root_vertex_handle  id) const
inlinevirtual

Given an Id return the address of the vertex having this Id in the complex.

Remarks
For a simplicial complex, the address is the id but it may not be the case for a SubComplex.

◆ get_id()

return the id of a vertex of address local present in the graph

◆ get_simplex_address()

template<class SkeletonBlockerDS >
boost::optional< Simplex > Gudhi::skeleton_blocker::Skeleton_blocker_complex< SkeletonBlockerDS >::get_simplex_address ( const Root_simplex_handle s) const
inline

Compute the local vertices of 's' in the current complex If one of them is not present in the complex then the return value is uninitialized.

◆ get_vertices()

template<class SkeletonBlockerDS >
Simplex Gudhi::skeleton_blocker::Skeleton_blocker_complex< SkeletonBlockerDS >::get_vertices ( Edge_handle  edge_handle) const
inline

returns the simplex made with the two vertices of the edge

it assumes that the edge is present in the complex

◆ is_cone()

Test if the complex is a cone.

Runs in O(n) where n is the number of vertices.

◆ is_contractible()

template<class SkeletonBlockerDS >
virtual contractible_status Gudhi::skeleton_blocker::Skeleton_blocker_complex< SkeletonBlockerDS >::is_contractible ( ) const
inlinevirtual

Test if the complex is reducible using a strategy defined in the class (by default it tests if the complex is a cone)

Note that NO could be returned if some invariant ensures that the complex is not a point (for instance if the euler characteristic is different from 1). This function will surely have to return MAYBE in some case because the associated problem is undecidable but it in practice, it can often be solved with the help of geometry.

◆ is_popable_blocker()

template<typename SkeletonBlockerDS >
bool Gudhi::skeleton_blocker::Skeleton_blocker_complex< SkeletonBlockerDS >::is_popable_blocker ( Blocker_handle  sigma) const

Returns true iff the blocker 'sigma' is popable. To define popable, let us call 'L' the complex that consists in the current complex without the blocker 'sigma'. A blocker 'sigma' is then "popable" if the link of 'sigma' in L is reducible.

Returns true if the blocker 'sigma' is popable. To define popable, let us call 'L' the complex that consists in the current complex without the blocker 'sigma'. A blocker 'sigma' is then "popable" if the link of 'sigma' in L is reducible.

◆ link() [1/3]

Constructs the link of 'simplex' with points coordinates.

◆ link() [2/3]

Constructs the link of 'simplex' with points coordinates.

◆ link() [3/3]

Constructs the link of 'simplex' with points coordinates.

◆ link_condition() [1/2]

template<class SkeletonBlockerDS >
bool Gudhi::skeleton_blocker::Skeleton_blocker_complex< SkeletonBlockerDS >::link_condition ( Edge_handle  e,
bool  ignore_popable_blockers = false 
) const
inline
Returns
If ignore_popable_blockers is true then the result is true iff the link condition at edge ab is satisfied or equivalently iff no blocker contains ab. If ignore_popable_blockers is false then the result is true iff all blocker containing ab are popable.

◆ link_condition() [2/2]

template<class SkeletonBlockerDS >
bool Gudhi::skeleton_blocker::Skeleton_blocker_complex< SkeletonBlockerDS >::link_condition ( Vertex_handle  a,
Vertex_handle  b,
bool  ignore_popable_blockers = false 
) const
inline
Returns
If ignore_popable_blockers is true then the result is true iff the link condition at edge ab is satisfied or equivalently iff no blocker contains ab. If ignore_popable_blockers is false then the result is true iff all blocker containing ab are popable.

◆ operator==()

return true if both complexes have the same simplices.

◆ operator[]() [1/3]

Return a local Vertex_handle of a vertex given a global one.

Remarks
Assume that the vertex is present in the complex.

◆ operator[]() [2/3]

Return the vertex node associated to local Vertex_handle.

Remarks
Assume that the vertex is present in the complex.

◆ operator[]() [3/3]

template<class SkeletonBlockerDS >
const Graph_vertex & Gudhi::skeleton_blocker::Skeleton_blocker_complex< SkeletonBlockerDS >::operator[] ( Vertex_handle  address) const
inline

Return the vertex node associated to local Vertex_handle.

Remarks
Assume that the vertex is present in the complex.

◆ remove_all_popable_blockers()

template<typename SkeletonBlockerDS >
void Gudhi::skeleton_blocker::Skeleton_blocker_complex< SkeletonBlockerDS >::remove_all_popable_blockers ( Vertex_handle  v)

Removes all the popable blockers of the complex passing through v and delete them. Also remove popable blockers in the neighborhood if they became popable.

◆ remove_blocker()

template<class SkeletonBlockerDS >
void Gudhi::skeleton_blocker::Skeleton_blocker_complex< SkeletonBlockerDS >::remove_blocker ( const Blocker_handle  sigma)
inline

Removes the simplex from the set of blockers.

Remarks
sigma has to belongs to the set of blockers

◆ remove_edge()

Removes an edge from the simplicial complex and all its cofaces.

returns the former Edge_handle representing the edge

◆ remove_popable_blockers() [1/2]

template<typename SkeletonBlockerDS >
void Gudhi::skeleton_blocker::Skeleton_blocker_complex< SkeletonBlockerDS >::remove_popable_blockers

Removes all the popable blockers of the complex and delete them.

◆ remove_popable_blockers() [2/2]

template<typename SkeletonBlockerDS >
void Gudhi::skeleton_blocker::Skeleton_blocker_complex< SkeletonBlockerDS >::remove_popable_blockers ( Vertex_handle  v)

Removes all the popable blockers of the complex passing through v and delete them.

◆ remove_star() [1/4]

template<typename SkeletonBlockerDS >
void Gudhi::skeleton_blocker::Skeleton_blocker_complex< SkeletonBlockerDS >::remove_star ( const Simplex sigma)

Remove the star of the simplex 'sigma' which needs to belong to the complex

◆ remove_star() [2/4]

Remove the star of the edge 'e'.

◆ remove_star() [3/4]

Remove the star of the edge connecting vertices a and b.

◆ remove_star() [4/4]

Remove the star of the vertex 'v'

Remove the star of the vertice 'v'

◆ remove_vertex()

template<class SkeletonBlockerDS >
void Gudhi::skeleton_blocker::Skeleton_blocker_complex< SkeletonBlockerDS >::remove_vertex ( Vertex_handle  address)
inline

Remove a vertex from the simplicial complex.

Remarks
It just deactivates the vertex with a boolean flag but does not remove it from vertices from complexity issues.

◆ second_vertex()

returns the first vertex of an edge

it assumes that the edge is present in the complex

◆ triangle_range() [1/2]

template<class SkeletonBlockerDS >
Complex_triangle_range Gudhi::skeleton_blocker::Skeleton_blocker_complex< SkeletonBlockerDS >::triangle_range ( ) const
inline

Range over triangles of the simplicial complex. Methods .begin() and .end() return a Triangle_around_vertex_iterator.

◆ triangle_range() [2/2]

template<class SkeletonBlockerDS >
Complex_triangle_around_vertex_range Gudhi::skeleton_blocker::Skeleton_blocker_complex< SkeletonBlockerDS >::triangle_range ( Vertex_handle  v) const
inline

Range over triangles around a vertex of the simplicial complex. Methods .begin() and .end() return a Triangle_around_vertex_iterator.


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