java.lang.Object

cloud.opencode.base.graph.algorithm.GraphMetrics

public final class GraphMetrics extends Object

Graph Metrics - Utility class for computing graph metrics and statistics 图度量 - 计算图度量和统计信息的工具类

Provides static methods for computing various graph metrics including density, eccentricity, diameter, radius, center, average path length, and clustering coefficient.

提供计算各种图度量的静态方法，包括密度、离心率、直径、半径、中心、平均路径长度和聚类系数。

Features | 主要功能:

Edge density calculation - 边密度计算
Eccentricity, diameter, and radius - 离心率、直径和半径
Graph center identification - 图中心识别
Average path length (BFS-based, unweighted) - 平均路径长度（基于BFS，无权）
Local and average clustering coefficient - 局部和平均聚类系数
Full graph summary - 完整图摘要

Usage Examples | 使用示例:

Graph<String> graph = OpenGraph.undirected();
graph.addEdge("A", "B");
graph.addEdge("B", "C");

double d = GraphMetrics.density(graph);
int diam = GraphMetrics.diameter(graph);
GraphMetrics.GraphSummary summary = GraphMetrics.summary(graph);

Since:

JDK 25, opencode-base-graph V1.0.3

Author:

Leon Soo www.LeonSoo.com

See Also:

Nested Class Summary

Nested Classes

Modifier and Type

Class

Description

static final record

GraphMetrics.GraphSummary

Graph summary record containing key metrics 包含关键度量的图摘要记录
Method Summary

Modifier and Type

Method

Description

static <V> double

averageClusteringCoefficient(Graph<V> graph)

Compute the average clustering coefficient over all vertices 计算所有顶点的平均聚类系数

static <V> double

averagePathLength(Graph<V> graph)

Compute the average shortest path length (BFS-based, unweighted) 计算平均最短路径长度（基于BFS，无权）

static <V> Set<V>

center(Graph<V> graph)

Find the center of a graph (vertices with eccentricity equal to the radius) 查找图的中心（离心率等于半径的顶点集合）

static <V> double

clusteringCoefficient(Graph<V> graph, V vertex)

Compute the local clustering coefficient of a vertex 计算顶点的局部聚类系数

static <V> double

density(Graph<V> graph)

Compute the edge density of a graph 计算图的边密度

static <V> int

diameter(Graph<V> graph)

Compute the diameter of a graph (max eccentricity over all vertices) 计算图的直径（所有顶点的最大离心率）

static <V> int

eccentricity(Graph<V> graph, V vertex)

Compute the eccentricity of a vertex (BFS-based, unweighted) 计算顶点的离心率（基于BFS，无权）

static <V> int

radius(Graph<V> graph)

Compute the radius of a graph (min eccentricity over all vertices) 计算图的半径（所有顶点的最小离心率）

static <V> GraphMetrics.GraphSummary

summary(Graph<V> graph)

Compute a full summary of graph metrics 计算完整的图度量摘要

Methods inherited from class Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Method Details
- density
  
  public static <V> double density(Graph<V> graph)
  
  Compute the edge density of a graph 计算图的边密度
  For directed graphs: E / (V * (V - 1)). For undirected graphs: 2 * E / (V * (V - 1)). Returns 0 if V <= 1.
  
  有向图: E / (V * (V - 1))。无向图: 2 * E / (V * (V - 1))。当 V <= 1 时返回 0。
  
  Type Parameters:
  
  V - the vertex type | 顶点类型
  
  Parameters:
  
  graph - the graph | 图
  
  Returns:
  
  the edge density in range [0, 1] | 边密度，范围 [0, 1]
  
  Throws:
  
  NullPointerException - if graph is null | 当图为null时抛出
- eccentricity
  
  public static <V> int eccentricity(Graph<V> graph, V vertex)
  
  Compute the eccentricity of a vertex (BFS-based, unweighted) 计算顶点的离心率（基于BFS，无权）
  The eccentricity is the maximum shortest path distance from the given vertex to any other reachable vertex. Returns Integer.MAX_VALUE if any vertex is unreachable from the given vertex.
  
  离心率是从给定顶点到任何其他可达顶点的最大最短路径距离。如果存在从该顶点不可达的顶点，则返回 Integer.MAX_VALUE。
  
  Type Parameters:
  
  V - the vertex type | 顶点类型
  
  Parameters:
  
  graph - the graph | 图
  
  vertex - the vertex | 顶点
  
  Returns:
  
  the eccentricity | 离心率
  
  Throws:
  
  NullPointerException - if graph or vertex is null | 当图或顶点为null时抛出
  
  IllegalArgumentException - if vertex is not in the graph | 当顶点不在图中时抛出
- diameter
  
  public static <V> int diameter(Graph<V> graph)
  
  Compute the diameter of a graph (max eccentricity over all vertices) 计算图的直径（所有顶点的最大离心率）
  Time complexity: O(V * (V + E)).
  
  时间复杂度: O(V * (V + E))。
  
  Type Parameters:
  
  V - the vertex type | 顶点类型
  
  Parameters:
  
  graph - the graph | 图
  
  Returns:
  
  the diameter, or 0 for empty/single-vertex graphs, Integer.MAX_VALUE for disconnected graphs | 直径，空图或单顶点图返回0，断开图返回Integer.MAX_VALUE
  
  Throws:
  
  NullPointerException - if graph is null | 当图为null时抛出
- radius
  
  public static <V> int radius(Graph<V> graph)
  
  Compute the radius of a graph (min eccentricity over all vertices) 计算图的半径（所有顶点的最小离心率）
  
  Type Parameters:
  
  V - the vertex type | 顶点类型
  
  Parameters:
  
  graph - the graph | 图
  
  Returns:
  
  the radius, or 0 for empty/single-vertex graphs, Integer.MAX_VALUE for disconnected graphs | 半径，空图或单顶点图返回0，断开图返回Integer.MAX_VALUE
  
  Throws:
  
  NullPointerException - if graph is null | 当图为null时抛出
- center
  
  public static <V> Set<V> center(Graph<V> graph)
  
  Find the center of a graph (vertices with eccentricity equal to the radius) 查找图的中心（离心率等于半径的顶点集合）
  
  Type Parameters:
  
  V - the vertex type | 顶点类型
  
  Parameters:
  
  graph - the graph | 图
  
  Returns:
  
  set of center vertices | 中心顶点集合
  
  Throws:
  
  NullPointerException - if graph is null | 当图为null时抛出
- averagePathLength
  
  public static <V> double averagePathLength(Graph<V> graph)
  
  Compute the average shortest path length (BFS-based, unweighted) 计算平均最短路径长度（基于BFS，无权）
  Only counts reachable pairs. Returns 0 if no reachable pairs exist.
  
  仅计算可达的顶点对。如果不存在可达的顶点对，返回0。
  
  Type Parameters:
  
  V - the vertex type | 顶点类型
  
  Parameters:
  
  graph - the graph | 图
  
  Returns:
  
  the average path length | 平均路径长度
  
  Throws:
  
  NullPointerException - if graph is null | 当图为null时抛出
- clusteringCoefficient
  
  public static <V> double clusteringCoefficient(Graph<V> graph, V vertex)
  
  Compute the local clustering coefficient of a vertex 计算顶点的局部聚类系数
  For a vertex v with k neighbors, the clustering coefficient is the ratio of actual edges among neighbors to the maximum possible edges. For undirected: edges / (k*(k-1)/2). For directed: edges / (k*(k-1)). Returns 0 if k < 2.
  
  对于具有k个邻居的顶点v，聚类系数是邻居之间实际边数与最大可能边数的比率。无向图: edges / (k*(k-1)/2)。有向图: edges / (k*(k-1))。当k < 2时返回0。
  
  Type Parameters:
  
  V - the vertex type | 顶点类型
  
  Parameters:
  
  graph - the graph | 图
  
  vertex - the vertex | 顶点
  
  Returns:
  
  the local clustering coefficient in range [0, 1] | 局部聚类系数，范围 [0, 1]
  
  Throws:
  
  NullPointerException - if graph or vertex is null | 当图或顶点为null时抛出
- averageClusteringCoefficient
  
  public static <V> double averageClusteringCoefficient(Graph<V> graph)
  
  Compute the average clustering coefficient over all vertices 计算所有顶点的平均聚类系数
  
  Type Parameters:
  
  V - the vertex type | 顶点类型
  
  Parameters:
  
  graph - the graph | 图
  
  Returns:
  
  the average clustering coefficient | 平均聚类系数
  
  Throws:
  
  NullPointerException - if graph is null | 当图为null时抛出
- summary
  
  public static <V> GraphMetrics.GraphSummary summary(Graph<V> graph)
  
  Compute a full summary of graph metrics 计算完整的图度量摘要
  
  Type Parameters:
  
  V - the vertex type | 顶点类型
  
  Parameters:
  
  graph - the graph | 图
  
  Returns:
  
  the graph summary | 图摘要
  
  Throws:
  
  NullPointerException - if graph is null | 当图为null时抛出

Class GraphMetrics

Nested Class Summary

Method Summary

Methods inherited from class Object

Method Details

density

eccentricity

diameter

radius

center

averagePathLength

clusteringCoefficient

averageClusteringCoefficient

summary