Fixed, documented NaN handling; changed internal counter to long; replaced pow with *.

git-svn-id: https://svn.apache.org/repos/asf/jakarta/commons/proper/math/trunk@141352 13f79535-47bb-0310-9956-ffa450edef68
This commit is contained in:
Phil Steitz 2004-06-29 15:39:15 +00:00
parent ee7756953e
commit 0def426df9
2 changed files with 13 additions and 18 deletions

View File

@ -25,7 +25,7 @@ import org.apache.commons.math.stat.univariate.AbstractStorelessUnivariateStatis
* If there are no values in the dataset, or any of the values are
* <code>NaN</code>, then <code>NaN</code> is returned.
*
* @version $Revision: 1.21 $ $Date: 2004/06/29 14:50:21 $
* @version $Revision: 1.22 $ $Date: 2004/06/29 15:39:15 $
*/
public class Sum extends AbstractStorelessUnivariateStatistic implements Serializable {
@ -33,7 +33,7 @@ public class Sum extends AbstractStorelessUnivariateStatistic implements Seriali
static final long serialVersionUID = -8231831954703408316L;
/** */
private int n = 0;
private long n = 0;
/**
* The currently running sum.

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@ -17,18 +17,15 @@ package org.apache.commons.math.stat.univariate.summary;
import java.io.Serializable;
import org
.apache
.commons
.math
.stat
.univariate
.AbstractStorelessUnivariateStatistic;
import org .apache.commons.math.stat.univariate.AbstractStorelessUnivariateStatistic;
/**
* Returns the sum of the squares of the available values.
*
* @version $Revision: 1.18 $ $Date: 2004/06/23 16:26:16 $
* <p>
* If there are no values in the dataset, or any of the values are
* <code>NaN</code>, then <code>NaN</code> is returned.
*
* @version $Revision: 1.19 $ $Date: 2004/06/29 15:39:15 $
*/
public class SumOfSquares extends AbstractStorelessUnivariateStatistic implements Serializable {
@ -36,7 +33,7 @@ public class SumOfSquares extends AbstractStorelessUnivariateStatistic implement
static final long serialVersionUID = 1460986908574398008L;
/** */
private int n = 0;
private long n = 0;
/**
* The currently running sumSq
@ -47,7 +44,7 @@ public class SumOfSquares extends AbstractStorelessUnivariateStatistic implement
* @see org.apache.commons.math.stat.univariate.StorelessUnivariateStatistic#increment(double)
*/
public void increment(final double d) {
if (Double.isNaN(value)) {
if (n == 0) {
value = d * d;
} else {
value += d * d;
@ -79,21 +76,19 @@ public class SumOfSquares extends AbstractStorelessUnivariateStatistic implement
/**
* Returns the sum of the squares of the available values.
*
* @param values Is a double[] containing the values
* @param begin processing at this point in the array
* @param length the number of elements to include
* @return the sum of the squared values or Double.NaN if the array is empty
* @see org.apache.commons.math.stat.univariate.UnivariateStatistic#evaluate(double[], int, int)
*/
public double evaluate(
final double[] values,
final int begin,
final int length) {
public double evaluate(final double[] values,final int begin, final int length) {
double sumSq = Double.NaN;
if (test(values, begin, length)) {
sumSq = 0.0;
for (int i = begin; i < begin + length; i++) {
sumSq += Math.pow(values[i], 2.0);
sumSq += values[i] * values[i];
}
}
return sumSq;