smile.graph

Class AdjacencyList

java.lang.Object

smile.graph.AdjacencyList

All Implemented Interfaces:

Graph

public class AdjacencyList
extends java.lang.Object
implements Graph

An adjacency list representation of a graph. Multigraph is supported.

Nested Class Summary

Nested classes/interfaces inherited from interface smile.graph.Graph

Graph.Edge

Constructor Summary

Constructors

Constructor and Description
AdjacencyList(int n) Constructor.
AdjacencyList(int n, boolean digraph) Constructor.

Method Summary

Modifier and Type	Method and Description
void	addEdge(int source, int target) Creates a new edge in this graph, going from the source vertex to the target vertex, and returns the created edge.
void	addEdge(int source, int target, double weight) Creates a new edge in this graph, going from the source vertex to the target vertex, and returns the created edge.
int[][]	bfs() Breadth-first search connected components of graph.
void	bfs(Visitor visitor) BFS search on graph and performs some operation defined in visitor on each vertex during traveling.
int[][]	dfs() Depth-first search connected components of graph.
void	dfs(Visitor visitor) DFS search on graph and performs some operation defined in visitor on each vertex during traveling.
double[]	dijkstra(int s) Calculate the shortest path from a source to all other vertices in the graph by Dijkstra algorithm.
int	getDegree(int vertex) Returns the degree of the specified vertex.
Graph.Edge	getEdge(int source, int target) Returns an edge connecting source vertex to target vertex if such edge exist in this graph.
java.util.Collection<Graph.Edge>	getEdges() Returns a set of the edges contained in this graph.
java.util.Collection<Graph.Edge>	getEdges(int vertex) Returns a set of all edges from the specified vertex.
java.util.Collection<Graph.Edge>	getEdges(int source, int target) Returns a set of all edges connecting source vertex to target vertex if such vertices exist in this graph.
int	getIndegree(int vertex) Returns the in-degree of the specified vertex.
int	getNumVertices() Returns the number vertices.
int	getOutdegree(int vertex) Returns the out-degree of the specified vertex.
double	getWeight(int source, int target) Returns the weight assigned to a given edge.
boolean	hasEdge(int source, int target) Returns true if and only if this graph contains an edge going from the source vertex to the target vertex.
static AdjacencyList	of(smile.math.matrix.SparseMatrix matrix) Converts the sparse matrix to a graph.
void	removeEdge(Graph.Edge edge) Removes the specified edge from the graph.* Returns true if the graph contained the specified edge.
void	removeEdge(int source, int target) In a simple graph, removes and returns the edge going from the specified source vertex to the specified target vertex.
void	removeEdges(java.util.Collection<Graph.Edge> edges) Removes a set of edges from the graph.
AdjacencyList	setWeight(int source, int target, double weight) Sets the weight assigned to a given edge.
int[]	sortbfs() Topological sort digraph by breadth-first search of graph.
int[]	sortdfs() Reverse topological sort digraph by depth-first search of graph.
AdjacencyList	subgraph(int[] vertices) Returns a subgraph containing all given vertices.
smile.math.matrix.SparseMatrix	toMatrix() Returns the (dense or sparse) matrix representation of the graph.

Methods inherited from class java.lang.Object

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

Methods inherited from interface smile.graph.Graph

dijkstra

Constructor Detail

AdjacencyList

public AdjacencyList(int n)

Constructor.

Parameters:

n - the number of vertices.

AdjacencyList

public AdjacencyList(int n,
                     boolean digraph)

Constructor.

Parameters:

n - the number of vertices.

digraph - true if this is a directed graph.

Method Detail

getNumVertices

public int getNumVertices()

Description copied from interface: Graph

Returns the number vertices.

Specified by:

getNumVertices in interface Graph

hasEdge

public boolean hasEdge(int source,
                       int target)

Description copied from interface: Graph

Returns true if and only if this graph contains an edge going from the source vertex to the target vertex. In undirected graphs the same result is obtained when source and target are inverted.

Specified by:

hasEdge in interface Graph

Parameters:

source - the id of source vertex of the edge.

target - the id of target vertex of the edge.

Returns:

true if this graph contains the specified edge.

getWeight

public double getWeight(int source,
                        int target)

Description copied from interface: Graph

Returns the weight assigned to a given edge. Unweighted graphs always return 1.0. For multi-graph, the return value is ill-defined.

Specified by:

getWeight in interface Graph

Parameters:

source - the id of source vertex of the edge.

target - the id of target vertex of the edge.

Returns:

the edge weight

setWeight

public AdjacencyList setWeight(int source,
                               int target,
                               double weight)

Description copied from interface: Graph

Sets the weight assigned to a given edge. For multi-graph, the operation is ill-defined.

Specified by:

setWeight in interface Graph

Parameters:

source - the id of source vertex of the edge.

target - the id of target vertex of the edge.

weight - the edge weight

getEdges

public java.util.Collection<Graph.Edge> getEdges()

Description copied from interface: Graph

Returns a set of the edges contained in this graph.

Specified by:

getEdges in interface Graph

getEdges

public java.util.Collection<Graph.Edge> getEdges(int vertex)

Description copied from interface: Graph

Returns a set of all edges from the specified vertex. If no edges are touching the specified vertex returns an empty set.

Specified by:

getEdges in interface Graph

Parameters:

vertex - the id of vertex for which a set of touching edges is to be returned.

Returns:

a set of all edges touching the specified vertex.

getEdges

public java.util.Collection<Graph.Edge> getEdges(int source,
                                                 int target)

Description copied from interface: Graph

Returns a set of all edges connecting source vertex to target vertex if such vertices exist in this graph. If both vertices exist but no edges found, returns an empty set.

In undirected graphs, some of the returned edges may have their source and target vertices in the opposite order.

Specified by:

getEdges in interface Graph

Parameters:

source - the id of source vertex of the edge.

target - the id of target vertex of the edge.

Returns:

a set of all edges connecting source vertex to target vertex.

getEdge

public Graph.Edge getEdge(int source,
                          int target)

Description copied from interface: Graph

Returns an edge connecting source vertex to target vertex if such edge exist in this graph. Otherwise returns null.

In undirected graphs, the returned edge may have its source and target vertices in the opposite order.

For multi-graph, the return value is ill-defined.

Specified by:

getEdge in interface Graph

Parameters:

source - the id of source vertex of the edge.

target - the id of target vertex of the edge.

Returns:

an edge connecting source vertex to target vertex if there are connected. Otherwise null.

addEdge

public void addEdge(int source,
                    int target)

Description copied from interface: Graph

Creates a new edge in this graph, going from the source vertex to the target vertex, and returns the created edge.

Specified by:

addEdge in interface Graph

Parameters:

source - the id of source vertex of the edge.

target - the id of target vertex of the edge.

addEdge

public void addEdge(int source,
                    int target,
                    double weight)

Description copied from interface: Graph

Creates a new edge in this graph, going from the source vertex to the target vertex, and returns the created edge.

Specified by:

addEdge in interface Graph

Parameters:

source - the id of source vertex of the edge.

target - the id of target vertex of the edge.

removeEdges

public void removeEdges(java.util.Collection<Graph.Edge> edges)

Description copied from interface: Graph

Removes a set of edges from the graph.

Specified by:

removeEdges in interface Graph

Parameters:

edges - edges to be removed from this graph.

removeEdge

public void removeEdge(int source,
                       int target)

Description copied from interface: Graph

In a simple graph, removes and returns the edge going from the specified source vertex to the specified target vertex.

Specified by:

removeEdge in interface Graph

Parameters:

source - the id of source vertex of the edge.

target - the id of target vertex of the edge.

removeEdge

public void removeEdge(Graph.Edge edge)

Description copied from interface: Graph

Removes the specified edge from the graph.* Returns true if the graph contained the specified edge.

Specified by:

removeEdge in interface Graph

Parameters:

edge - edge to be removed from this graph, if present.

getDegree

public int getDegree(int vertex)

Description copied from interface: Graph

Returns the degree of the specified vertex. A degree of a vertex in an undirected graph is the number of edges touching that vertex.

Specified by:

getDegree in interface Graph

Parameters:

vertex - the id of vertex.

Returns:

the degree of the specified vertex.

getIndegree

public int getIndegree(int vertex)

Description copied from interface: Graph

Returns the in-degree of the specified vertex. A in-degree of a vertex in an directed graph is the number of edges head to that vertex.

Specified by:

getIndegree in interface Graph

Parameters:

vertex - the id of vertex.

Returns:

the degree of the specified vertex.

getOutdegree

public int getOutdegree(int vertex)

Description copied from interface: Graph

Returns the out-degree of the specified vertex. A out-degree of a vertex in an directed graph is the number of edges from that vertex.

Specified by:

getOutdegree in interface Graph

Parameters:

vertex - the id of vertex.

Returns:

the degree of the specified vertex.

sortdfs

public int[] sortdfs()

Description copied from interface: Graph

Reverse topological sort digraph by depth-first search of graph.

Specified by:

sortdfs in interface Graph

Returns:

an array of vertex IDs in the reverse topological order.

dfs

public int[][] dfs()

Description copied from interface: Graph

Depth-first search connected components of graph.

Specified by:

dfs in interface Graph

Returns:

a two-dimensional array of which each row is the vertices in the same connected component.

dfs

public void dfs(Visitor visitor)

Description copied from interface: Graph

DFS search on graph and performs some operation defined in visitor on each vertex during traveling.

Specified by:

dfs in interface Graph

Parameters:

visitor - the visitor functor.

sortbfs

public int[] sortbfs()

Description copied from interface: Graph

Topological sort digraph by breadth-first search of graph.

Specified by:

sortbfs in interface Graph

Returns:

an array of vertex IDs in the topological order.

bfs

public int[][] bfs()

Description copied from interface: Graph

Breadth-first search connected components of graph.

Specified by:

bfs in interface Graph

Returns:

a two-dimensional array of which each row is the vertices in the same connected component.

bfs

public void bfs(Visitor visitor)

Description copied from interface: Graph

BFS search on graph and performs some operation defined in visitor on each vertex during traveling.

Specified by:

bfs in interface Graph

Parameters:

visitor - the visitor functor.

dijkstra

public double[] dijkstra(int s)

Description copied from interface: Graph

Calculate the shortest path from a source to all other vertices in the graph by Dijkstra algorithm.

Specified by:

dijkstra in interface Graph

Parameters:

s - the source vertex.

Returns:

the length of shortest path to other vertices.

subgraph

public AdjacencyList subgraph(int[] vertices)

Description copied from interface: Graph

Returns a subgraph containing all given vertices.

Specified by:

subgraph in interface Graph

Parameters:

vertices - the vertices to be included in subgraph.

Returns:

a subgraph containing all given vertices

toMatrix

public smile.math.matrix.SparseMatrix toMatrix()

Description copied from interface: Graph

Returns the (dense or sparse) matrix representation of the graph.

Specified by:

toMatrix in interface Graph

of

public static AdjacencyList of(smile.math.matrix.SparseMatrix matrix)

Converts the sparse matrix to a graph. If the matrix is structurally symmetric, it is taken as the adjacency matrix of an undirected graph, where two vertices i and j are connected if the (i, j)-th entry of the matrix is nonzero. Rectangular or structurally asymmetric matrices are treated as bipartite graphs.

Returns:

a graph