Example usage for com.google.common.graph GraphBuilder from

Introduction

In this page you can find the example usage for com.google.common.graph GraphBuilder from.

Prototype

public static <N> GraphBuilder<N> from(Graph<N> graph) 

Source Link

Document

Returns a GraphBuilder initialized with all properties queryable from graph .

Usage

From source file:edu.uci.ics.jung.algorithms.filters.KNeighborhoodFilter.java

public static <N> MutableGraph<N> filterGraph(Graph<N> graph, Set<N> rootNodes, int radius) {
    checkNotNull(graph);//  w  w w.ja v a2 s. com
    checkNotNull(rootNodes);
    checkArgument(graph.nodes().containsAll(rootNodes), "graph must contain all of rootNodes");
    checkArgument(radius > 0, "radius must be > 0");

    MutableGraph<N> filtered = GraphBuilder.from(graph).build();
    for (N root : rootNodes) {
        filtered.addNode(root);
    }
    Queue<N> currentNodes = new ArrayDeque<>(rootNodes);
    Queue<N> nextNodes = new ArrayDeque<>();

    for (int depth = 1; depth <= radius && !currentNodes.isEmpty(); depth++) {
        while (!currentNodes.isEmpty()) {
            N currentNode = currentNodes.remove();
            for (N nextNode : graph.successors(currentNode)) {
                // the addNode needs to happen before putEdge() because we need to know whether
                // the node was present in the graph
                // (and putEdge() will always add the node if not present)
                if (filtered.addNode(nextNode)) {
                    nextNodes.add(nextNode);
                }
                filtered.putEdge(currentNode, nextNode);
            }
        }
        Queue<N> emptyQueue = currentNodes;
        currentNodes = nextNodes;
        nextNodes = emptyQueue;
    }

    // put in in-edges from nodes in the filtered graph
    for (N node : filtered.nodes()) {
        for (N predecessor : graph.predecessors(node)) {
            if (filtered.nodes().contains(predecessor)) {
                filtered.putEdge(predecessor, node);
            }
        }
    }

    return filtered;
}

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