我正在尝试从Java Jung Graph软件包构造以下内容:Edmondskarp对象
EdmondsKarpMaxFlow<MyNode, MyLink> alg = new EdmondsKarpMaxFlow<MyNode, MyLink>(g, n2, n5, capTransformer, edgeFlowMap, flowEdgeFactory);
我不知道为什么有错误,这是Netbeans的错误消息:
reason: actual argument org.apache.commons.collections15.Transformer<selfsimilarity.MyLink,java.lang.Double> cannot be converted to org.apache.commons.collections15.Transformer<selfsimilarity.MyLink,java.lang.Number> by method invocation conversion
。
我本质上是遵循教程。
edmondskarpmaxflow实例化在构造函数的底部。在构造函数之后,我将所有参数的代码提供给Edmondskarp对象。这些参数是图形,源和接收器节点,容量变压器,地图和边缘工厂。
public GraphAlgTests()
{
g = new DirectedSparseMultigraph<MyNode, MyLink>();
// Create some MyNode objects to use as vertices
MyNode n1 = new MyNode(1); MyNode n2 = new MyNode(2); MyNode n3 = new MyNode(3);
MyNode n4 = new MyNode(4); MyNode n5 = new MyNode(5);
// Add some directed edges along with the vertices to the graph
g.addEdge(new MyLink(2.0, 48),n1, n2, EdgeType.DIRECTED); // This method
g.addEdge(new MyLink(2.0, 48),n2, n3, EdgeType.DIRECTED);
g.addEdge(new MyLink(3.0, 192), n3, n5, EdgeType.DIRECTED);
g.addEdge(new MyLink(2.0, 48), n5, n4, EdgeType.DIRECTED); // or we can use
g.addEdge(new MyLink(2.0, 48), n4, n2); // In a directed graph the
g.addEdge(new MyLink(2.0, 48), n3, n1); // first node is the source
g.addEdge(new MyLink(10.0, 48), n2, n5);// and the second the destination
EdmondsKarpMaxFlow<MyNode, MyLink> alg = new EdmondsKarpMaxFlow<MyNode, MyLink>(g, n2, n5, capTransformer, edgeFlowMap, flowEdgeFactory);
}
public class MyNode
{
private int id; // good coding practice would have this as private
public MyNode(int id)
{
this.id = id;
}
public String toString()
{ // Always a good idea for debuging
return "v"+id; // JUNG2 makes good use of these.
}
}
public class MyLink
{
double capacity; // should be private
double weight; // should be private for good practice
int id;
int edgeCount = 0;
public MyLink(double weight, double capacity)
{
this.id = edgeCount++;
this.weight = weight;
this.capacity = capacity;
}
public String toString()
{ // Always good for debugging
return "E"+id;
}
}
Transformer<MyLink, Double> capTransformer = new Transformer<MyLink, Double>()
//INFO: Gives the capacity of an edge, denoted here as a "link"
{
@Override
public Double transform(MyLink link)
{
return link.capacity;
}
};
Map<MyLink, Double> edgeFlowMap = new HashMap<MyLink, Double>();
Factory<MyLink> flowEdgeFactory = new Factory<MyLink>()
{
@Override
public MyLink create()
{
return new MyLink(1.0, 1.0);
}
};
如果还有其他帮助,请告诉我!感谢您的所有帮助!
它告诉您该构造函数的Javadoc告诉您什么:
public EdmondsKarpMaxFlow(DirectedGraph<V,E> directedGraph,
V source,
V sink,
org.apache.commons.collections15.Transformer<E,Number> edgeCapacityTransformer,
Map<E,Number> edgeFlowMap,
org.apache.commons.collections15.Factory<E> edgeFactory)
您的Transformer
是<MyLink, Double>
,当需要为<MyLink, Number>
时(并且您的transform()
方法需要定义以返回Number
)
这可能在API中的某个时刻更改,并且您使用的教程已过时。现在,API很可能在您将返回的Number
对象上调用doubleValue()
。
对于您的edgeFlowMap
也将看起来也一样。