org.nlpub.watset.util.ABCFormat Maven / Gradle / Ivy

Go to download

Show more of this group Show more artifacts with this name
Show all versions of watset Show documentation

An open source implementation of the Watset algorithm for fuzzy graph clustering.

There is a newer version: 2.8.2

/*
 * Copyright 2019 Dmitry Ustalov
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 *
 */

package org.nlpub.watset.util;

import org.jgrapht.Graph;
import org.jgrapht.graph.DefaultWeightedEdge;
import org.jgrapht.graph.SimpleWeightedGraph;

import java.util.stream.Stream;

/**
 * Utilities for handling the ABC {@code (source, target, weight)} edge list format.
 */
public final class ABCFormat {
    private ABCFormat() {
        throw new UnsupportedOperationException("This is a utility class and cannot be instantiated");
    }

    /**
     * The default separator, expressed by the tab symbol.
     */
    public static final String SEPARATOR = "\t";

    /**
     * Parse the string stream of ABC-formatted edges.
     *
     * @param stream the input stream
     * @param regex  the separator regular expression
     * @return the graph represented in the stream
     */
    public static Graph parse(Stream stream, String regex) {
        final var builder = SimpleWeightedGraph.createBuilder(DefaultWeightedEdge.class);

        stream.forEach(line -> {
            final var split = line.split(regex);

            if (split.length != 3 || split[0].equals(split[1])) return;

            builder.addVertices(split[0], split[1]);

            builder.addEdge(split[0], split[1], Double.parseDouble(split[2]));
        });

        return builder.build();
    }

    /**
     * Parse the string stream of ABC-formatted edges.
     *
     * @param stream the input stream
     * @return the graph represented in the stream
     */
    public static Graph parse(Stream stream) {
        return parse(stream, SEPARATOR);
    }
}