| /* |
| * 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.math4.legacy.stat.descriptive.rank; |
| |
| import org.apache.commons.math4.legacy.core.MathArrays; |
| |
| /** |
| * A mid point strategy based on the average of begin and end indices. |
| * @since 3.4 |
| */ |
| public class CentralPivotingStrategy implements PivotingStrategy { |
| /** |
| * {@inheritDoc} |
| * This in particular picks a average of begin and end indices |
| * @return The index corresponding to a simple average of |
| * the first and the last element indices of the array slice |
| * @throws org.apache.commons.math4.legacy.exception.MathIllegalArgumentException MathIllegalArgumentException when indices exceeds range |
| */ |
| @Override |
| public int pivotIndex(final double[] work, final int begin, final int end) { |
| MathArrays.verifyValues(work, begin, end - begin); |
| return begin + (end - begin)/2; |
| } |
| } |
