| /* |
| * 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.openejb.math.stat.descriptive.rank; |
| |
| import java.io.Serializable; |
| |
| import org.apache.openejb.math.stat.descriptive.AbstractStorelessUnivariateStatistic; |
| |
| /** |
| * Returns the minimum of the available values. |
| * <p> |
| * <ul> |
| * <li>The result is <code>NaN</code> iff all values are <code>NaN</code> |
| * (i.e. <code>NaN</code> values have no impact on the value of the statistic).</li> |
| * <li>If any of the values equals <code>Double.NEGATIVE_INFINITY</code>, |
| * the result is <code>Double.NEGATIVE_INFINITY.</code></li> |
| * </ul></p> |
| * <p> |
| * <strong>Note that this implementation is not synchronized.</strong> If |
| * multiple threads access an instance of this class concurrently, and at least |
| * one of the threads invokes the <code>increment()</code> or |
| * <code>clear()</code> method, it must be synchronized externally.</p> |
| * |
| * @version $Revision: 811685 $ $Date: 2009-09-05 10:36:48 -0700 (Sat, 05 Sep 2009) $ |
| */ |
| public class Min extends AbstractStorelessUnivariateStatistic implements Serializable { |
| |
| /** Serializable version identifier */ |
| private static final long serialVersionUID = -1231995784909003131L; |
| |
| /**Number of values that have been added */ |
| private long n; |
| |
| /**Current value of the statistic */ |
| private double value; |
| |
| /** |
| * Create a Min instance |
| */ |
| public Min() { |
| n = 0; |
| value = Double.NaN; |
| } |
| |
| /** |
| * Copy constructor, creates a new {@code Min} identical |
| * to the {@code original} |
| * |
| * @param original the {@code Min} instance to copy |
| */ |
| public Min(Min original) { |
| copy(original, this); |
| } |
| |
| /** |
| * {@inheritDoc} |
| */ |
| @Override |
| public void increment(final double d) { |
| if (d < value || Double.isNaN(value)) { |
| value = d; |
| } |
| n++; |
| } |
| |
| /** |
| * {@inheritDoc} |
| */ |
| @Override |
| public void clear() { |
| value = Double.NaN; |
| n = 0; |
| } |
| |
| /** |
| * {@inheritDoc} |
| */ |
| @Override |
| public double getResult() { |
| return value; |
| } |
| |
| /** |
| * {@inheritDoc} |
| */ |
| public long getN() { |
| return n; |
| } |
| |
| /** |
| * Returns the minimum of the entries in the specified portion of |
| * the input array, or <code>Double.NaN</code> if the designated subarray |
| * is empty. |
| * <p> |
| * Throws <code>IllegalArgumentException</code> if the array is null or |
| * the array index parameters are not valid.</p> |
| * <p> |
| * <ul> |
| * <li>The result is <code>NaN</code> iff all values are <code>NaN</code> |
| * (i.e. <code>NaN</code> values have no impact on the value of the statistic).</li> |
| * <li>If any of the values equals <code>Double.NEGATIVE_INFINITY</code>, |
| * the result is <code>Double.NEGATIVE_INFINITY.</code></li> |
| * </ul> </p> |
| * |
| * @param values the input array |
| * @param begin index of the first array element to include |
| * @param length the number of elements to include |
| * @return the minimum of the values or Double.NaN if length = 0 |
| * @throws IllegalArgumentException if the array is null or the array index |
| * parameters are not valid |
| */ |
| @Override |
| public double evaluate(final double[] values,final int begin, final int length) { |
| double min = Double.NaN; |
| if (test(values, begin, length)) { |
| min = values[begin]; |
| for (int i = begin; i < begin + length; i++) { |
| if (!Double.isNaN(values[i])) { |
| min = (min < values[i]) ? min : values[i]; |
| } |
| } |
| } |
| return min; |
| } |
| |
| /** |
| * {@inheritDoc} |
| */ |
| @Override |
| public Min copy() { |
| Min result = new Min(); |
| copy(this, result); |
| return result; |
| } |
| |
| /** |
| * Copies source to dest. |
| * <p>Neither source nor dest can be null.</p> |
| * |
| * @param source Min to copy |
| * @param dest Min to copy to |
| * @throws NullPointerException if either source or dest is null |
| */ |
| public static void copy(Min source, Min dest) { |
| dest.n = source.n; |
| dest.value = source.value; |
| } |
| } |