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 */ 017 018package org.apache.commons.math3.stat.ranking; 019 020/** 021 * Strategies for handling NaN values in rank transformations. 022 * <ul> 023 * <li>MINIMAL - NaNs are treated as minimal in the ordering, equivalent to 024 * (that is, tied with) <code>Double.NEGATIVE_INFINITY</code>.</li> 025 * <li>MAXIMAL - NaNs are treated as maximal in the ordering, equivalent to 026 * <code>Double.POSITIVE_INFINITY</code></li> 027 * <li>REMOVED - NaNs are removed before the rank transform is applied</li> 028 * <li>FIXED - NaNs are left "in place," that is the rank transformation is 029 * applied to the other elements in the input array, but the NaN elements 030 * are returned unchanged.</li> 031 * <li>FAILED - If any NaN is encountered in the input array, an appropriate 032 * exception is thrown</li> 033 * </ul> 034 * 035 * @since 2.0 036 * @version $Id: NaNStrategy.java 1422313 2012-12-15 18:53:41Z psteitz $ 037 */ 038public enum NaNStrategy { 039 040 /** NaNs are considered minimal in the ordering */ 041 MINIMAL, 042 043 /** NaNs are considered maximal in the ordering */ 044 MAXIMAL, 045 046 /** NaNs are removed before computing ranks */ 047 REMOVED, 048 049 /** NaNs are left in place */ 050 FIXED, 051 052 /** NaNs result in an exception 053 * @since 3.1 054 */ 055 FAILED 056}