CODEWITHSUNDEEP
javagraphgraph-theoryvertex
Chris
Chris

Reputation: 815

printing graph vertex and edge source/target - JGraphT

I'm creating a graph of flights where the user I want to be able to print my graph out like:

Edinburgh <-> Heathrow
Heathrow <-> Amsterdam
etc....

I have an idea to do this by getting the edge source and the edge target, the edge being the "<->" , the source being for example "Edinburgh" and the target being "Heathrow".

I've tried looping through the String array and printing, such as graph.getEdge(sourceVertext, targetVertex), but I can't seem to get it working.

I'll only use a couple of examples in the code.

Note: If I try printing the array after setting edge weights, I get an illegal argument exception. If anyone could please explain why this is happening that would also be great :) thanks.

public static void main(String[] args) {

    SimpleDirectedWeightedGraph<String, DefaultWeightedEdge> airport = new SimpleDirectedWeightedGraph<String, DefaultWeightedEdge>(
            DefaultWeightedEdge.class);

    String[] array = { "Edinburgh", "Heathrow", "Amsterdam" };

    System.out.println(" ");
    System.out.println("The following destinations are used: " + "\n");

    for (String s : array) {
        System.out.println(s); // prints the array elements
    }

    System.out.print("");

    for (String s : array) {
        System.out.print(airport.getEdgeSource(s) + airport.getEdgeTarget(s));
        // OR....
        // System.out.print(airport.getEdge(sourceVertex, targetVertex));
    }

    DefaultWeightedEdge EH1 = airport.addEdge("Edinburgh", "Heathrow");
    DefaultWeightedEdge HE1 = airport.addEdge("Heathrow", "Edinburgh");
    airport.setEdgeWeight(EH1, 110);
    airport.setEdgeWeight(HE1, 110);

    DefaultWeightedEdge HA2 = airport.addEdge("Heathrow", "Amsterdam");
    DefaultWeightedEdge AH2 = airport.addEdge("Amsterdam", "Heathrow");
    airport.setEdgeWeight(HA2, 100);
    airport.setEdgeWeight(AH2, 100);

    System.out.println("");
}

Upvotes: 1

Views: 5019

Answers (1)

Chris
Chris

Reputation: 815

I've since figured out how to display the edge source and target:

for(DefaultWeightedEdge e : airport.edgeSet()){
    System.out.println(airport.getEdgeSource(e) + " --> " + airport.getEdgeTarget(e));
}

This displays it like:

Edinburgh --> Heathrow
Heathrow --> Edinburgh

Thanks.

Upvotes: 3

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