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/* * 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.descriptive; import org.apache.commons.math3.exception.util.LocalizedFormats; import org.apache.commons.math3.exception.MathIllegalArgumentException; import org.apache.commons.math3.exception.NullArgumentException; import org.apache.commons.math3.util.MathUtils; import org.apache.commons.math3.util.Precision; /** * * Abstract implementation of the {@link StorelessUnivariateStatistic} interface. * <p> * Provides default <code>evaluate()</code> and <code>incrementAll(double[])</code> * implementations.</p> * <p> * <strong>Note that these implementations are not synchronized.</strong></p> * * @version $Id: AbstractStorelessUnivariateStatistic.java 1416643 2012-12-03 19:37:14Z tn $ */ public abstract class AbstractStorelessUnivariateStatistic extends AbstractUnivariateStatistic implements StorelessUnivariateStatistic { /** * This default implementation calls {@link #clear}, then invokes * {@link #increment} in a loop over the the input array, and then uses * {@link #getResult} to compute the return value. * <p> * Note that this implementation changes the internal state of the * statistic. Its side effects are the same as invoking {@link #clear} and * then {@link #incrementAll(double[])}.</p> * <p> * Implementations may override this method with a more efficient and * possibly more accurate implementation that works directly with the * input array.</p> * <p> * If the array is null, a MathIllegalArgumentException is thrown.</p> * @param values input array * @return the value of the statistic applied to the input array * @throws MathIllegalArgumentException if values is null * @see org.apache.commons.math3.stat.descriptive.UnivariateStatistic#evaluate(double[]) */ @Override public double evaluate(final double[] values) throws MathIllegalArgumentException { if (values == null) { throw new NullArgumentException(LocalizedFormats.INPUT_ARRAY); } return evaluate(values, 0, values.length); } /** * This default implementation calls {@link #clear}, then invokes * {@link #increment} in a loop over the specified portion of the input * array, and then uses {@link #getResult} to compute the return value. * <p> * Note that this implementation changes the internal state of the * statistic. Its side effects are the same as invoking {@link #clear} and * then {@link #incrementAll(double[], int, int)}.</p> * <p> * Implementations may override this method with a more efficient and * possibly more accurate implementation that works directly with the * input array.</p> * <p> * If the array is null or the index parameters are not valid, an * MathIllegalArgumentException is thrown.</p> * @param values the input array * @param begin the index of the first element to include * @param length the number of elements to include * @return the value of the statistic applied to the included array entries * @throws MathIllegalArgumentException if the array is null or the indices are not valid * @see org.apache.commons.math3.stat.descriptive.UnivariateStatistic#evaluate(double[], int, int) */ @Override public double evaluate(final double[] values, final int begin, final int length) throws MathIllegalArgumentException { if (test(values, begin, length)) { clear(); incrementAll(values, begin, length); } return getResult(); } /** * {@inheritDoc} */ @Override public abstract StorelessUnivariateStatistic copy(); /** * {@inheritDoc} */ public abstract void clear(); /** * {@inheritDoc} */ public abstract double getResult(); /** * {@inheritDoc} */ public abstract void increment(final double d); /** * This default implementation just calls {@link #increment} in a loop over * the input array. * <p> * Throws IllegalArgumentException if the input values array is null.</p> * * @param values values to add * @throws MathIllegalArgumentException if values is null * @see org.apache.commons.math3.stat.descriptive.StorelessUnivariateStatistic#incrementAll(double[]) */ public void incrementAll(double[] values) throws MathIllegalArgumentException { if (values == null) { throw new NullArgumentException(LocalizedFormats.INPUT_ARRAY); } incrementAll(values, 0, values.length); } /** * This default implementation just calls {@link #increment} in a loop over * the specified portion of the input array. * <p> * Throws IllegalArgumentException if the input values array is null.</p> * * @param values array holding values to add * @param begin index of the first array element to add * @param length number of array elements to add * @throws MathIllegalArgumentException if values is null * @see org.apache.commons.math3.stat.descriptive.StorelessUnivariateStatistic#incrementAll(double[], int, int) */ public void incrementAll(double[] values, int begin, int length) throws MathIllegalArgumentException { if (test(values, begin, length)) { int k = begin + length; for (int i = begin; i < k; i++) { increment(values[i]); } } } /** * Returns true iff <code>object</code> is an * <code>AbstractStorelessUnivariateStatistic</code> returning the same * values as this for <code>getResult()</code> and <code>getN()</code> * @param object object to test equality against. * @return true if object returns the same value as this */ @Override public boolean equals(Object object) { if (object == this) { return true; } if (object instanceof AbstractStorelessUnivariateStatistic == false) { return false; } AbstractStorelessUnivariateStatistic stat = (AbstractStorelessUnivariateStatistic) object; return Precision.equalsIncludingNaN(stat.getResult(), this.getResult()) && Precision.equalsIncludingNaN(stat.getN(), this.getN()); } /** * Returns hash code based on getResult() and getN() * * @return hash code */ @Override public int hashCode() { return 31 * (31 + MathUtils.hash(getResult())) + MathUtils.hash(getN()); } }