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.math.stat.ranking; 19 20 /** 21 * Interface representing a rank transformation. 22 * 23 * @since 2.0 24 * @version $Revision: 811685 $ $Date: 2009-09-05 19:36:48 +0200 (sam. 05 sept. 2009) $ 25 */ 26 public interface RankingAlgorithm { 27 /** 28 * <p>Performs a rank transformation on the input data, returning an array 29 * of ranks.</p> 30 * 31 * <p>Ranks should be 1-based - that is, the smallest value 32 * returned in an array of ranks should be greater than or equal to one, 33 * rather than 0. Ranks should in general take integer values, though 34 * implementations may return averages or other floating point values 35 * to resolve ties in the input data.</p> 36 * 37 * @param data array of data to be ranked 38 * @return an array of ranks corresponding to the elements of the input array 39 */ 40 double[] rank (double[] data); 41 } 42