# OpenGraph DrawingFramework

v. 2022.02 (Dogwood)

ogdf::PertinentGraph Class Reference

Pertinent graphs of nodes in an SPQR-tree. More...

#include <ogdf/decomposition/PertinentGraph.h>

## Public Member Functions

PertinentGraph ()
Creates an empty instance of type PertinentGraph. More...

GraphgetGraph ()
Returns a reference to G(vT). More...

const GraphgetGraph () const
Returns a reference to G(vT). More...

void init (node vT)
Initialization of a pertinent graph of tree node vT. More...

edge original (edge e) const
Returns the edge in G that corresponds to e. More...

node original (node v) const
Returns the vertex in G that corresponds to v. More...

edge referenceEdge () const
Returns the edge in G(vT) corresponding to the reference edge in skeleton of vT. More...

edge skeletonReferenceEdge () const
Returns the reference edge in skeleton of vT. More...

node treeNode () const
Returns the tree node vT in T whose pertinent graph is this one. More...

## Protected Attributes

EdgeArray< edgem_origE
corresp. More...

NodeArray< nodem_origV
corresp. More...

Graph m_P
actual graph More...

edge m_skRefEdge
reference edge (in skeleton(m_vT)) More...

edge m_vEdge
reference edge (in m_P) More...

node m_vT
corresponding tree node More...

class SPQRTree

## Detailed Description

Pertinent graphs of nodes in an SPQR-tree.

The class PertinentGraph represents the pertinent graph G(vT) of a node vT in an SPQR-tree T with original graph G.

The expansion graph E(e) of a virtual skeleton edge e is the skeleton graph of the twin e' of e without e', where each virtual edge eV again is replaced by its expansion graph E(eV). The pertinent graph G(vT) of a tree node vT is obtained from the skeleton S of vT, where each edge except for the reference edge of S is replaced by its expansion graph. Hence, if vT is not the root node of T, all but one edge in G(vT) correspond to real edges, otherwise all edges correspond to real edges.

If P is the pertinent graph of a PlanarSPQRTree, the underlying graph represents the combinatorial embedding which is implied by the embeddings of the skeletons of T.

Definition at line 59 of file PertinentGraph.h.

## ◆ PertinentGraph()

 ogdf::PertinentGraph::PertinentGraph ( )
inline

Creates an empty instance of type PertinentGraph.

Remarks
Pertinent graphs are created by the pertinentGraph() function of SPQRTree.

Definition at line 74 of file PertinentGraph.h.

## ◆ getGraph() [1/2]

 Graph& ogdf::PertinentGraph::getGraph ( )
inline

Returns a reference to G(vT).

Definition at line 97 of file PertinentGraph.h.

## ◆ getGraph() [2/2]

 const Graph& ogdf::PertinentGraph::getGraph ( ) const
inline

Returns a reference to G(vT).

Definition at line 92 of file PertinentGraph.h.

## ◆ init()

 void ogdf::PertinentGraph::init ( node vT )
inline

Initialization of a pertinent graph of tree node vT.

Definition at line 77 of file PertinentGraph.h.

## ◆ original() [1/2]

 edge ogdf::PertinentGraph::original ( edge e ) const
inline

Returns the edge in G that corresponds to e.

If e is the reference edge, then 0 is returned.

Precondition
e is an edge in G(vT)

Definition at line 131 of file PertinentGraph.h.

## ◆ original() [2/2]

 node ogdf::PertinentGraph::original ( node v ) const
inline

Returns the vertex in G that corresponds to v.

Precondition
v is a node in G(vT)

Definition at line 122 of file PertinentGraph.h.

## ◆ referenceEdge()

 edge ogdf::PertinentGraph::referenceEdge ( ) const
inline

Returns the edge in G(vT) corresponding to the reference edge in skeleton of vT.

If vT is the root of T, then 0 is returned.

Definition at line 105 of file PertinentGraph.h.

## ◆ skeletonReferenceEdge()

 edge ogdf::PertinentGraph::skeletonReferenceEdge ( ) const
inline

Returns the reference edge in skeleton of vT.

Notice that this edge may differ from the current reference edge in skeleton of vT if T has been rerooted after the construction of P.

Definition at line 114 of file PertinentGraph.h.

## ◆ treeNode()

 node ogdf::PertinentGraph::treeNode ( ) const
inline

Returns the tree node vT in T whose pertinent graph is this one.

Definition at line 87 of file PertinentGraph.h.

## ◆ SPQRTree

 friend class SPQRTree
friend

Definition at line 61 of file PertinentGraph.h.

## ◆ m_origE

 EdgeArray ogdf::PertinentGraph::m_origE
protected

corresp.

original edge

Definition at line 142 of file PertinentGraph.h.

## ◆ m_origV

 NodeArray ogdf::PertinentGraph::m_origV
protected

corresp.

original node

Definition at line 141 of file PertinentGraph.h.

## ◆ m_P

 Graph ogdf::PertinentGraph::m_P
protected

actual graph

Definition at line 137 of file PertinentGraph.h.

## ◆ m_skRefEdge

 edge ogdf::PertinentGraph::m_skRefEdge
protected

reference edge (in skeleton(m_vT))

Definition at line 139 of file PertinentGraph.h.

## ◆ m_vEdge

 edge ogdf::PertinentGraph::m_vEdge
protected

reference edge (in m_P)

Definition at line 138 of file PertinentGraph.h.

## ◆ m_vT

 node ogdf::PertinentGraph::m_vT
protected

corresponding tree node

Definition at line 136 of file PertinentGraph.h.

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