001/*
002 * Licensed to the Apache Software Foundation (ASF) under one or more
003 * contributor license agreements.  See the NOTICE file distributed with
004 * this work for additional information regarding copyright ownership.
005 * The ASF licenses this file to You under the Apache License, Version 2.0
006 * (the "License"); you may not use this file except in compliance with
007 * the License.  You may obtain a copy of the License at
008 *
009 *      http://www.apache.org/licenses/LICENSE-2.0
010 *
011 * Unless required by applicable law or agreed to in writing, software
012 * distributed under the License is distributed on an "AS IS" BASIS,
013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014 * See the License for the specific language governing permissions and
015 * limitations under the License.
016 */
017package org.apache.commons.text.similarity;
018
019/**
020 * Measures the Jaccard distance of two sets of character sequence. Jaccard
021 * distance is the dissimilarity between two sets. It is the complementary of
022 * Jaccard similarity.
023 *
024 * <p>
025 * For further explanation about Jaccard Distance, refer
026 * https://en.wikipedia.org/wiki/Jaccard_index
027 * </p>
028 *
029 * @since 1.0
030 */
031public class JaccardDistance implements EditDistance<Double> {
032
033    /**
034     * Calculates Jaccard distance of two set character sequence passed as
035     * input. Calculates Jaccard similarity and returns the complement of it.
036     *
037     * @param left first character sequence
038     * @param right second character sequence
039     * @return index
040     * @throws IllegalArgumentException
041     *             if either String input {@code null}
042     */
043    @Override
044    public Double apply(final CharSequence left, final CharSequence right) {
045        if (left == null || right == null) {
046            throw new IllegalArgumentException("Input cannot be null");
047        }
048        return 1.0 - JaccardSimilarity.INSTANCE.apply(left, right).doubleValue();
049    }
050}