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 * Strategies for handling NaN values in rank transformations. 22 * <ul> 23 * <li>MINIMAL - NaNs are treated as minimal in the ordering, equivalent to 24 * (that is, tied with) <code>Double.NEGATIVE_INFINITY</code>.</li> 25 * <li>MAXIMAL - NaNs are treated as maximal in the ordering, equivalent to 26 * <code>Double.POSITIVE_INFINITY</code></li> 27 * <li>REMOVED - NaNs are removed before the rank transform is applied</li> 28 * <li>FIXED - NaNs are left "in place," that is the rank transformation is 29 * applied to the other elements in the input array, but the NaN elements 30 * are returned unchanged.</li> 31 * </ul> 32 * 33 * @since 2.0 34 * @version $Revision: 811685 $ $Date: 2009-09-05 19:36:48 +0200 (sam. 05 sept. 2009) $ 35 */ 36 public enum NaNStrategy { 37 38 /** NaNs are considered minimal in the ordering */ 39 MINIMAL, 40 41 /** NaNs are considered maximal in the ordering */ 42 MAXIMAL, 43 44 /** NaNs are removed before computing ranks */ 45 REMOVED, 46 47 /** NaNs are left in place */ 48 FIXED 49 } 50