Coverage Report - org.apache.commons.math.stat.descriptive.summary.Product

Classes in this File	Line Coverage	Branch Coverage	Complexity
Product	100%	100%	1.5;1.5

1		/*
2		* Copyright 2003-2004 The Apache Software Foundation.
3		*
4		* Licensed under the Apache License, Version 2.0 (the "License");
5		* you may not use this file except in compliance with the License.
6		* You may obtain a copy of the License at
7		*
8		* http://www.apache.org/licenses/LICENSE-2.0
9		*
10		* Unless required by applicable law or agreed to in writing, software
11		* distributed under the License is distributed on an "AS IS" BASIS,
12		* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13		* See the License for the specific language governing permissions and
14		* limitations under the License.
15		*/
16		package org.apache.commons.math.stat.descriptive.summary;
17
18		import java.io.Serializable;
19
20		import org.apache.commons.math.stat.descriptive.AbstractStorelessUnivariateStatistic;
21
22		/**
23		* Returns the product of the available values.
24		* <p>
25		* If there are no values in the dataset, or any of the values are
26		* <code>NaN</code>, then <code>NaN</code> is returned.
27		* <p>
28		* <strong>Note that this implementation is not synchronized.</strong> If
29		* multiple threads access an instance of this class concurrently, and at least
30		* one of the threads invokes the <code>increment()</code> or
31		* <code>clear()</code> method, it must be synchronized externally.
32		*
33		* @version $Revision$ $Date: 2005-02-26 05:11:52 -0800 (Sat, 26 Feb 2005) $
34		*/
35		public class Product extends AbstractStorelessUnivariateStatistic implements Serializable {
36
37		/** Serializable version identifier */
38		static final long serialVersionUID = 2824226005990582538L;
39
40		/**The number of values that have been added */
41		private long n;
42
43		/**
44		* The current Running Product.
45		*/
46		private double value;
47
48		/**
49		* Create a Product instance
50		*/
51	26	public Product() {
52	26	n = 0;
53	26	value = Double.NaN;
54	26	}
55
56		/**
57		* @see org.apache.commons.math.stat.descriptive.StorelessUnivariateStatistic#increment(double)
58		*/
59		public void increment(final double d) {
60	170	if (n == 0) {
61	20	value = d;
62		} else {
63	150	value *= d;
64		}
65	170	n++;
66	170	}
67
68		/**
69		* @see org.apache.commons.math.stat.descriptive.StorelessUnivariateStatistic#getResult()
70		*/
71		public double getResult() {
72	98	return value;
73		}
74
75		/**
76		* @see org.apache.commons.math.stat.descriptive.StorelessUnivariateStatistic#getN()
77		*/
78		public long getN() {
79	58	return n;
80		}
81
82		/**
83		* @see org.apache.commons.math.stat.descriptive.StorelessUnivariateStatistic#clear()
84		*/
85		public void clear() {
86	22	value = Double.NaN;
87	22	n = 0;
88	22	}
89
90		/**
91		* Returns the product of the entries in the specified portion of
92		* the input array, or <code>Double.NaN</code> if the designated subarray
93		* is empty.
94		* <p>
95		* Throws <code>IllegalArgumentException</code> if the array is null.
96		*
97		* @param values the input array
98		* @param begin index of the first array element to include
99		* @param length the number of elements to include
100		* @return the product of the values or Double.NaN if length = 0
101		* @throws IllegalArgumentException if the array is null or the array index
102		* parameters are not valid
103		*/
104		public double evaluate(final double[] values, final int begin, final int length) {
105	28	double product = Double.NaN;
106	28	if (test(values, begin, length)) {
107	20	product = 1.0;
108	144	for (int i = begin; i < begin + length; i++) {
109	124	product *= values[i];
110		}
111		}
112	26	return product;
113		}
114
115		}