salvo.jesus.graph

Interface WeightedGraph

All Superinterfaces:

Graph, Serializable

All Known Implementing Classes:

WeightedGraphImpl

public interface WeightedGraph
extends Graph

A interface for a Graph where all edges have a specified weight.

Author:

Jesus M. Salvo Jr.

Method Summary

Modifier and Type	Method and Description
WeightedEdge	addEdge(Vertex v1, Vertex v2, double weight) Convenience method to add a WeightedEdge with a specified weight into the WeightedGraph.
Vertex	getClosest(Vertex v) Determines the Vertex that is 'closest' to the Vertex specified.
WeightedGraph	minimumSpanningTree() Determine a minimum spanning tree for the weighted graph.
WeightedGraph	shortestPath(Vertex vertex) Determine a shortest path spanning tree for the weighted graph.

Methods inherited from interface salvo.jesus.graph.Graph

add, addEdge, addEdge, addGraphAddEdgeListener, addGraphAddVertexListener, addGraphRemoveEdgeListener, addGraphRemoveVertexListener, addListener, cloneVertices, getAdjacentVertices, getAdjacentVertices, getConnectedSet, getConnectedSet, getDegree, getDegree, getEdges, getEdgesCount, getEdgeSet, getGraphFactory, getTraversal, getVertexSet, getVertices, getVerticesCount, getVerticesIterator, isConnected, remove, removeEdge, removeEdges, removeGraphAddEdgeListener, removeGraphAddVertexListener, removeGraphRemoveEdgeListener, removeGraphRemoveVertexListener, removeListener, setGraphFactory, setTraversal, traverse

Method Detail

addEdge

WeightedEdge addEdge(Vertex v1,
                     Vertex v2,
                     double weight)
              throws Exception

Convenience method to add a WeightedEdge with a specified weight into the WeightedGraph. The default addEdge( v1, v2 ) will add a WeightedEdge with zero weight, after which you can call setWeight() to specify the weight.

Returns:

The WeightedEdge that has been added.

Throws:

Exception

getClosest

Vertex getClosest(Vertex v)

Determines the Vertex that is 'closest' to the Vertex specified. The definition of the closest vertex in this context is a vertex that is directly adjacent to Vertex v where the edge has the least weight.

Returns:

The Vertex closes to Vertex v.

minimumSpanningTree

WeightedGraph minimumSpanningTree()

Determine a minimum spanning tree for the weighted graph. There is no guarantee that the same method call will result in the same result, as long as it satisifies the property of a minimum spanning tree.

Returns:

Subgraph connecting all the Vertices such that the sum of the weights of the Edges is at least as small as the sum of the weights of any other collection of Edges connecting all the Vertices.

shortestPath

WeightedGraph shortestPath(Vertex vertex)

Determine a shortest path spanning tree for the weighted graph. Shortest path spanning tree need not be unique. Therefore, there is no guarantee that calling this method twice for the same weighted graph will return exactly the same shortest path spanning tree, unless there is only one shortest path spanning tree.

Also note that the graph returned by this method is a new instance of WeightedGraph. However, its vertices and edges will be the same instance as those of this WeightedGraph. Therefore, do not modify the contents of the returned WeightedGraph such that any of its vertices or edges are removed.

Parameters:

vertex - The Vertex in the weighted graph that we want to get the shortest paths to all other vertices.

Returns:

Shortest spanning tree subgraph from the vertex parameter to all other vertices that are in the same connected set as the vertex.