Class Coreness<V,E>
- java.lang.Object
-
- org.jgrapht.alg.scoring.Coreness<V,E>
-
- Type Parameters:
V
- the graph vertex typeE
- the graph edge type
- All Implemented Interfaces:
VertexScoringAlgorithm<V,java.lang.Integer>
public final class Coreness<V,E> extends java.lang.Object implements VertexScoringAlgorithm<V,java.lang.Integer>
Computes the coreness of each vertex in an undirected graph.A $k$-core of a graph $G$ is a maximal connected subgraph of $G$ in which all vertices have degree at least $k$. Equivalently, it is one of the connected components of the subgraph of $G$ formed by repeatedly deleting all vertices of degree less than $k$. A vertex $u$ has coreness $c$ if it belongs to a $c$-core but not to any $(c+1)$-core.
If a non-empty k-core exists, then, clearly, $G$ has degeneracy at least $k$, and the degeneracy of $G$ is the largest $k$ for which $G$ has a $k$-core.
As described in the following paper
- D. W. Matula and L. L. Beck. Smallest-last ordering and clustering and graph coloring algorithms. Journal of the ACM, 30(3):417--427, 1983.
- Author:
- Dimitrios Michail
-
-
Method Summary
All Methods Instance Methods Concrete Methods Modifier and Type Method Description int
getDegeneracy()
Compute the degeneracy of a graph.java.util.Map<V,java.lang.Integer>
getScores()
Get a map with the scores of all verticesjava.lang.Integer
getVertexScore(V v)
Get a vertex score
-
-
-
Method Detail
-
getScores
public java.util.Map<V,java.lang.Integer> getScores()
Get a map with the scores of all vertices- Specified by:
getScores
in interfaceVertexScoringAlgorithm<V,E>
- Returns:
- a map with all scores
-
getVertexScore
public java.lang.Integer getVertexScore(V v)
Get a vertex score- Specified by:
getVertexScore
in interfaceVertexScoringAlgorithm<V,E>
- Parameters:
v
- the vertex- Returns:
- the score
-
getDegeneracy
public int getDegeneracy()
Compute the degeneracy of a graph.The degeneracy of a graph is the smallest value of $k$ for which it is $k$-degenerate. In graph theory, a $k$-degenerate graph is an undirected graph in which every subgraph has a vertex of degree at most $k$: that is, some vertex in the subgraph touches $k$ or fewer of the subgraph's edges.
- Returns:
- the degeneracy of a graph
-
-