1 /*
2 * Licensed to the Apache Software Foundation (ASF) under one or more
3 * contributor license agreements. See the NOTICE file distributed with
4 * this work for additional information regarding copyright ownership.
5 * The ASF licenses this file to You under the Apache License, Version 2.0
6 * (the "License"); you may not use this file except in compliance with
7 * the License. You may obtain a copy of the License at
8 *
9 * http://www.apache.org/licenses/LICENSE-2.0
10 *
11 * Unless required by applicable law or agreed to in writing, software
12 * distributed under the License is distributed on an "AS IS" BASIS,
13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14 * See the License for the specific language governing permissions and
15 * limitations under the License.
16 */
17
18 package org.apache.commons.math4.legacy.ml.clustering;
19
20 import java.util.List;
21
22 /**
23 * Evaluates the quality of a set of clusters.
24 * It is assumed that
25 * <ul>
26 * <li>rank is positive,</li>
27 * <li>higher rank means better clustering.</li>
28 * </ul>
29 */
30 @FunctionalInterface
31 public interface ClusterRanking {
32 /**
33 * Computes the rank (higher is better).
34 *
35 * @param clusters Clusters to be evaluated.
36 * @return the rank of the provided {@code clusters}.
37 */
38 double compute(List<? extends Cluster<? extends Clusterable>> clusters);
39 }