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Posted to commits@commons.apache.org by lu...@apache.org on 2015/12/09 17:01:10 UTC

[13/21] [math] Fixed errors / omissions in javadoc regarding NaN return values. JIRA: MATH-1296.

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/field-ode
Commit: c23e9fb1a1612bda5377b9e062d133a96a057cea
Parents: 26ad6ac
Author: Phil Steitz <ph...@gmail.com>
Authored: Wed Dec 2 20:40:19 2015 -0700
Committer: Phil Steitz <ph...@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 &lt;=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 &lt;=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