/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.commons.math3.stat.ranking;
/**
* Strategies for handling NaN values in rank transformations.
* <ul>
* <li>MINIMAL - NaNs are treated as minimal in the ordering, equivalent to
* (that is, tied with) <code>Double.NEGATIVE_INFINITY</code>.</li>
* <li>MAXIMAL - NaNs are treated as maximal in the ordering, equivalent to
* <code>Double.POSITIVE_INFINITY</code></li>
* <li>REMOVED - NaNs are removed before the rank transform is applied</li>
* <li>FIXED - NaNs are left "in place," that is the rank transformation is
* applied to the other elements in the input array, but the NaN elements
* are returned unchanged.</li>
* <li>FAILED - If any NaN is encountered in the input array, an appropriate
* exception is thrown</li>
* </ul>
*
* @since 2.0
*/
public enum NaNStrategy {
/** NaNs are considered minimal in the ordering */
MINIMAL,
/** NaNs are considered maximal in the ordering */
MAXIMAL,
/** NaNs are removed before computing ranks */
REMOVED,
/** NaNs are left in place */
FIXED,
/** NaNs result in an exception
* @since 3.1
*/
FAILED
}