Repository: commons-math
Updated Branches:
refs/heads/MATH_3_X 26ad6ac83 -> c23e9fb1a
Fixed errors / omissions in javadoc regarding NaN return values. JIRA: MATH-1296.
Project: http://git-wip-us.apache.org/repos/asf/commons-math/repo
Commit: http://git-wip-us.apache.org/repos/asf/commons-math/commit/c23e9fb1
Tree: http://git-wip-us.apache.org/repos/asf/commons-math/tree/c23e9fb1
Diff: http://git-wip-us.apache.org/repos/asf/commons-math/diff/c23e9fb1
Branch: refs/heads/MATH_3_X
Commit: c23e9fb1a1612bda5377b9e062d133a96a057cea
Parents: 26ad6ac
Author: Phil Steitz <phil.steitz@gmail.com>
Authored: Wed Dec 2 20:40:19 2015 -0700
Committer: Phil Steitz <phil.steitz@gmail.com>
Committed: Wed Dec 2 20:40:19 2015 -0700
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.../stat/descriptive/DescriptiveStatistics.java | 17 ++++++++++-------
.../math3/stat/descriptive/moment/Skewness.java | 5 +++++
2 files changed, 15 insertions(+), 7 deletions(-)
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http://git-wip-us.apache.org/repos/asf/commons-math/blob/c23e9fb1/src/main/java/org/apache/commons/math3/stat/descriptive/DescriptiveStatistics.java
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diff --git a/src/main/java/org/apache/commons/math3/stat/descriptive/DescriptiveStatistics.java
b/src/main/java/org/apache/commons/math3/stat/descriptive/DescriptiveStatistics.java
index 31acd24..b215bc8 100644
--- a/src/main/java/org/apache/commons/math3/stat/descriptive/DescriptiveStatistics.java
+++ b/src/main/java/org/apache/commons/math3/stat/descriptive/DescriptiveStatistics.java
@@ -208,9 +208,12 @@ public class DescriptiveStatistics implements StatisticalSummary, Serializable
{
/**
* Returns the <a href="http://www.xycoon.com/geometric_mean.htm">
- * geometric mean </a> of the available values
+ * geometric mean </a> of the available values.
+ * <p>
+ * See {@link GeometricMean} for details on the computing algorithm.</p>
+ *
* @return The geometricMean, Double.NaN if no values have been added,
- * or if the product of the available values is less than or equal to 0.
+ * or if any negative values have been added.
*/
public double getGeometricMean() {
return apply(geometricMeanImpl);
@@ -273,8 +276,8 @@ public class DescriptiveStatistics implements StatisticalSummary, Serializable
{
/**
* Returns the skewness of the available values. Skewness is a
* measure of the asymmetry of a given distribution.
- * @return The skewness, Double.NaN if no values have been added
- * or 0.0 for a value set <=2.
+ *
+ * @return The skewness, Double.NaN if less than 3 values have been added.
*/
public double getSkewness() {
return apply(skewnessImpl);
@@ -282,9 +285,9 @@ public class DescriptiveStatistics implements StatisticalSummary, Serializable
{
/**
* Returns the Kurtosis of the available values. Kurtosis is a
- * measure of the "peakedness" of a distribution
- * @return The kurtosis, Double.NaN if no values have been added, or 0.0
- * for a value set <=3.
+ * measure of the "peakedness" of a distribution.
+ *
+ * @return The kurtosis, Double.NaN if less than 4 values have been added.
*/
public double getKurtosis() {
return apply(kurtosisImpl);
http://git-wip-us.apache.org/repos/asf/commons-math/blob/c23e9fb1/src/main/java/org/apache/commons/math3/stat/descriptive/moment/Skewness.java
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diff --git a/src/main/java/org/apache/commons/math3/stat/descriptive/moment/Skewness.java
b/src/main/java/org/apache/commons/math3/stat/descriptive/moment/Skewness.java
index 9ecb0dd..b4703eb 100644
--- a/src/main/java/org/apache/commons/math3/stat/descriptive/moment/Skewness.java
+++ b/src/main/java/org/apache/commons/math3/stat/descriptive/moment/Skewness.java
@@ -34,6 +34,11 @@ import org.apache.commons.math3.util.MathUtils;
* where n is the number of values, mean is the {@link Mean} and std is the
* {@link StandardDeviation} </p>
* <p>
+ * Note that this statistic is undefined for n < 3. <code>Double.Nan</code>
+ * is returned when there is not sufficient data to compute the statistic.
+ * Double.NaN may also be returned if the input includes NaN and / or
+ * infinite values.</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
|