org.jgrapht.graph.guava.MutableDoubleValueGraphAdapter Maven / Gradle / Ivy
/*
* (C) Copyright 2018-2018, by Dimitrios Michail and Contributors.
*
* JGraphT : a free Java graph-theory library
*
* This program and the accompanying materials are dual-licensed under
* either
*
* (a) the terms of the GNU Lesser General Public License version 2.1
* as published by the Free Software Foundation, or (at your option) any
* later version.
*
* or (per the licensee's choosing)
*
* (b) the terms of the Eclipse Public License v1.0 as published by
* the Eclipse Foundation.
*/
package org.jgrapht.graph.guava;
import com.google.common.graph.*;
import org.jgrapht.Graph;
import java.io.*;
import java.util.function.*;
/**
* A graph adapter class using Guava's {@link MutableValueGraph} specialized with double values.
*
*
* The adapter uses class {@link EndpointPair} to represent edges. Changes in the adapter such as
* adding or removing vertices and edges are reflected in the underlying value graph.
*
*
* Each edge in {@link MutableValueGraph} is associated with a double value which is mapped to the
* edge weight in the resulting {@link Graph}. Thus, the graph is weighted and calling methods
* {@link #getEdgeWeight(Object)} and {@link #setEdgeWeight(EndpointPair, double)} will get and set
* the value of an edge.
*
*
* See the example below on how to create such an adapter:
*
*
* MutableValueGraph<String, Double> mutableValueGraph =
* ValueGraphBuilder.directed().allowsSelfLoops(true).build();
*
* mutableValueGraph.addNode("v1");
* mutableValueGraph.addNode("v2");
* mutableValueGraph.putEdgeValue("v1", "v2", 3.0);
*
* Graph<String, EndpointPair<String>> graph = new MutableDoubleValueGraphAdapter<>(mutableValueGraph);
*
* System.out.println(graph.getEdgeWeight(EndpointPair.ordered("v1", "v2")); // outputs 3.0
*
* graph.setEdgeWeight(EndpointPair.ordered("v1", "v2"), 7.0);
*
* System.out.println(graph.getEdgeWeight(EndpointPair.ordered("v1", "v2")); // outputs 7.0
*
*
*
*
* @author Dimitrios Michail
*
* @param the graph vertex type
*/
public class MutableDoubleValueGraphAdapter
extends
MutableValueGraphAdapter
{
private static final long serialVersionUID = -6335845255406679994L;
/**
* Create a new adapter.
*
* @param valueGraph the value graph
*/
public MutableDoubleValueGraphAdapter(MutableValueGraph valueGraph)
{
this(valueGraph, null, null);
}
/**
* Create a new adapter.
*
* @param valueGraph the value graph
* @param vertexSupplier the vertex supplier
* @param edgeSupplier the edge supplier
*/
public MutableDoubleValueGraphAdapter(
MutableValueGraph valueGraph, Supplier vertexSupplier,
Supplier> edgeSupplier)
{
super(
valueGraph, Graph.DEFAULT_EDGE_WEIGHT, (ToDoubleFunction & Serializable) x -> x,
vertexSupplier, edgeSupplier);
}
@Override
public void setEdgeWeight(EndpointPair e, double weight)
{
if (e == null) {
throw new NullPointerException();
}
if (!containsEdge(e)) {
throw new IllegalArgumentException("no such edge in graph: " + e.toString());
}
super.valueGraph.putEdgeValue(e.nodeU(), e.nodeV(), weight);
}
}