graph

Class Graph.Contraction

java.lang.Object

la.la.Value

graph.Graph

graph.Graph.Derived

graph.Graph.Contraction

All Implemented Interfaces:

Child, Graph.SubGraph, java.lang.Comparable<Value>

Enclosing class:

Graph

public class Graph.Contraction
extends Graph.Derived
implements Graph.SubGraph

A Vertex-Contraction of 'this' Graph, collapsing (identifying) Vertices [vs[0], vs[1], ...] onto the single Vertex vs[0]. Vertex-contraction is the opposite of Vertex-expansion. Also see contraction(vs).

Nested Class Summary

Nested classes/interfaces inherited from class graph.Graph

Graph.Canonical, Graph.Contraction, Graph.Dense, Graph.Derived, Graph.Edge, Graph.Induced, Graph.Renumbered, Graph.Sparse, Graph.SubGraph, Graph.SubGraphs, Graph.ToDirected, Graph.ToUndirected, Graph.Vertex

Nested classes/interfaces inherited from class la.la.Value

Value.Atomic, Value.Bool, Value.Char, Value.Chars, Value.Cts, Value.Defer, Value.Discrete, Value.Enum, Value.Inc_Or, Value.Int, Value.Lambda, Value.List, Value.Maybe, Value.Option, Value.Real, Value.Scannable, Value.Structured, Value.Triv, Value.Tuple

Field Summary

Fields

Modifier and Type	Field and Description
int[]	vs The contracted vertices of the parent Graph.

Fields inherited from class la.la.Value

C, comparator, CR, E, eight, ffalse, five, fiveR, four, fourR, half, negCR, negOne, negOneR, negTenR, nilVal, nine, None, one, oneR, PI, PIby2, point01, point1, point5, point9, quarter, seven, six, ten, tenR, three, threeR, triv, ttrue, two, twoR, zero, zeroR

Constructor Summary

Constructors

Constructor and Description
Contraction(int[] vs) vs must be a subset of the parent Graph's {0, ..., vSize()-1}.

Method Summary

Modifier and Type	Method and Description
Value	eLabel(int v0, int v1) Edge labels, if any, as per v2pv and the parent Graph.
boolean	isEdge(int v0, int v1) If v0 and/or v1 is vs[0] to which >1 vertices of the parent Graph are contracted, was there an Edge from/to any of the latter in the parent?
java.lang.String	toString() Used, for example, in printing of constants, and in calls to Value.error(java.lang.String).
int	v2pv(int v) The Vertex of the parent that 'v' corresponds to.
Value	vLabel(int v) Vertex labels, if any, as per v2pv and the parent Graph.
int	vSize() The number of Vertices in 'this' Contracted Graph.

Methods inherited from class graph.Graph.Derived

parent, type

Methods inherited from class graph.Graph

A, adjacent, arrayA, byDegree, byDegree, canonical, canonical1, canonical1R, canonical2, canonical2R, checkProperties, contraction, degree, dense, dense, directPredecessors, directSuccessors, edges, edgesCorrespond, eLabelled, eLabels, eSize, eStats, flatten, hashCode, inDegree, induced, isDirected, isomorphic, isUndirected, joinedTo, localHash, main, maxEdges, nAutomorphisms, outDegree, randomised, renumbered, selfLoops, structurallyIdentical, subGraphs, subGraphs, toDirected, toUndirected, vLabelled, vLabels, vPair2n

Methods inherited from class la.la.Value

AoM, apply, bOp, compareTo, cons, cts, elt, errMsg, error, force, isTuple, just, n, nElts, nlAoM, pair, print, quad, real, RTE, triple, tuple, UOE, uOp, x

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, notify, notifyAll, wait, wait, wait

Methods inherited from interface graph.Child

parent

Field Detail

vs

public final int[] vs

The contracted vertices of the parent Graph. Note, vs is in ascending order! vs[0] has some special uses.

Constructor Detail

Contraction

public Contraction(int[] vs)

vs must be a subset of the parent Graph's {0, ..., vSize()-1}.

Method Detail

vSize

public int vSize()

The number of Vertices in 'this' Contracted Graph. For a non-trivial contraction this is less than the parent's.

Overrides:

vSize in class Graph.Derived

v2pv

public int v2pv(int v)

The Vertex of the parent that 'v' corresponds to. If, say, vertices x<y<z (of the parent) are the contracted vertices then a Vertex v in the Contraction maps to its old Vertex number in the parent, which is the same number if v≤x and is >v otherwise.

Specified by:

v2pv in interface Graph.SubGraph

isEdge

public boolean isEdge(int v0,
                      int v1)

If v0 and/or v1 is vs[0] to which >1 vertices of the parent Graph are contracted, was there an Edge from/to any of the latter in the parent?

Overrides:

isEdge in class Graph.Derived

vLabel

public Value vLabel(int v)

Vertex labels, if any, as per v2pv and the parent Graph. If v corresponds to >1 Vertices of the parent, return any one of their labels.

Overrides:

vLabel in class Graph

eLabel

public Value eLabel(int v0,
                    int v1)

Edge labels, if any, as per v2pv and the parent Graph. Involves an arbitrary choice if v0 and/or v1 corresponds to >1 Vertices of the parent Graph.

Overrides:

eLabel in class Graph

toString

public java.lang.String toString()

Description copied from class: Value

Used, for example, in printing of constants, and in calls to Value.error(java.lang.String). The result does not necessarily fully specify a large, or infinite(!), Value. (This default returns the Class Name of 'this'.) Also see print(ps).

Overrides:

toString in class Value