From f18c6b1affed026d32bd380526526e4b411f265b Mon Sep 17 00:00:00 2001 From: Phil Steitz Date: Sat, 9 Feb 2008 23:42:44 +0000 Subject: [PATCH] Added getSumOfLogs method to SummaryStatistics and made sum of logs instance used by GeometricMean configurable. JIRA: MATH-191 git-svn-id: https://svn.apache.org/repos/asf/commons/proper/math/trunk@620221 13f79535-47bb-0310-9956-ffa450edef68 --- .../stat/descriptive/SummaryStatistics.java | 23 ++++++++-- .../descriptive/moment/GeometricMean.java | 46 ++++++++++++++++++- src/site/xdoc/changes.xml | 6 ++- .../descriptive/SummaryStatisticsTest.java | 42 +++-------------- 4 files changed, 75 insertions(+), 42 deletions(-) diff --git a/src/java/org/apache/commons/math/stat/descriptive/SummaryStatistics.java b/src/java/org/apache/commons/math/stat/descriptive/SummaryStatistics.java index a1526d720..bed7f0669 100644 --- a/src/java/org/apache/commons/math/stat/descriptive/SummaryStatistics.java +++ b/src/java/org/apache/commons/math/stat/descriptive/SummaryStatistics.java @@ -120,7 +120,7 @@ public class SummaryStatistics implements StatisticalSummary, Serializable { protected SumOfLogs sumLog = new SumOfLogs(); /** geoMean of values that have been added */ - protected GeometricMean geoMean = new GeometricMean(); + protected GeometricMean geoMean = new GeometricMean(sumLog); /** mean of values that have been added */ protected Mean mean = new Mean(); @@ -174,16 +174,18 @@ public class SummaryStatistics implements StatisticalSummary, Serializable { minImpl.increment(value); maxImpl.increment(value); sumLogImpl.increment(value); - geoMean.increment(value); secondMoment.increment(value); - // If mean or variance have been overridden, - // need to increment these, since they don't have secondMoment + // If mean, variance or geomean have been overridden, + // need to increment these if (!(meanImpl instanceof Mean)) { meanImpl.increment(value); } if (!(varianceImpl instanceof Variance)) { varianceImpl.increment(value); } + if (!(geoMeanImpl instanceof GeometricMean)) { + geoMeanImpl.increment(value); + } n++; } @@ -296,6 +298,17 @@ public class SummaryStatistics implements StatisticalSummary, Serializable { return geoMeanImpl.getResult(); } + /** + * Returns the sum of the logs of the values that have been added. + *

+ * Double.NaN is returned if no values have been added.

+ * + * @return the sum of logs + */ + public double getSumOfLogs() { + return sumLogImpl.getResult(); + } + /** * Generates a text report displaying * summary statistics from values that @@ -313,6 +326,7 @@ public class SummaryStatistics implements StatisticalSummary, Serializable { outBuffer.append("variance: " + getVariance() + "\n"); outBuffer.append("sum of squares: " + getSumsq() + "\n"); outBuffer.append("standard deviation: " + getStandardDeviation() + "\n"); + outBuffer.append("sum of logs: " + getSumOfLogs() + "\n"); return outBuffer.toString(); } @@ -505,6 +519,7 @@ public class SummaryStatistics implements StatisticalSummary, Serializable { StorelessUnivariateStatistic sumLogImpl) { checkEmpty(); this.sumLogImpl = sumLogImpl; + geoMean.setSumLogImpl(sumLogImpl); } /** diff --git a/src/java/org/apache/commons/math/stat/descriptive/moment/GeometricMean.java b/src/java/org/apache/commons/math/stat/descriptive/moment/GeometricMean.java index 18d535910..a52196557 100644 --- a/src/java/org/apache/commons/math/stat/descriptive/moment/GeometricMean.java +++ b/src/java/org/apache/commons/math/stat/descriptive/moment/GeometricMean.java @@ -17,6 +17,7 @@ package org.apache.commons.math.stat.descriptive.moment; import org.apache.commons.math.stat.descriptive.AbstractStorelessUnivariateStatistic; +import org.apache.commons.math.stat.descriptive.StorelessUnivariateStatistic; import org.apache.commons.math.stat.descriptive.summary.SumOfLogs; /** @@ -49,7 +50,7 @@ public class GeometricMean extends AbstractStorelessUnivariateStatistic { private static final long serialVersionUID = -8178734905303459453L; /** Wrapped SumOfLogs instance */ - private SumOfLogs sumOfLogs; + private StorelessUnivariateStatistic sumOfLogs; /** * Create a GeometricMean instance @@ -58,6 +59,13 @@ public class GeometricMean extends AbstractStorelessUnivariateStatistic { sumOfLogs = new SumOfLogs(); } + /** + * Create a GeometricMean instance using the given SumOfLogs instance + */ + public GeometricMean(SumOfLogs sumOfLogs) { + this.sumOfLogs = sumOfLogs; + } + /** * @see org.apache.commons.math.stat.descriptive.StorelessUnivariateStatistic#increment(double) */ @@ -111,5 +119,41 @@ public class GeometricMean extends AbstractStorelessUnivariateStatistic { public long getN() { return sumOfLogs.getN(); } + + /** + *

Sets the implementation for the sum of logs.

+ *

This method must be activated before any data has been added - i.e., + * before {@link #addValue(double) addValue} has been used to add data; + * otherwise an IllegalStateException will be thrown.

+ * + * @param sumLogImpl the StorelessUnivariateStatistic instance to use + * for computing the log sum + * @throws IllegalStateException if data has already been added + * (i.e if n > 0) + */ + public void setSumLogImpl( + StorelessUnivariateStatistic sumLogImpl) { + checkEmpty(); + this.sumOfLogs = sumLogImpl; + } + + /** + * Returns the currently configured sum of logs implementation + * + * @return the StorelessUnivariateStatistic implementing the log sum + */ + public StorelessUnivariateStatistic getSumLogImpl() { + return sumOfLogs; + } + + /** + * Throws IllegalStateException if n > 0. + */ + private void checkEmpty() { + if (getN() > 0) { + throw new IllegalStateException( + "Implementation must be configured before values are added."); + } + } } \ No newline at end of file diff --git a/src/site/xdoc/changes.xml b/src/site/xdoc/changes.xml index 90172aa3c..637206792 100644 --- a/src/site/xdoc/changes.xml +++ b/src/site/xdoc/changes.xml @@ -162,7 +162,11 @@ Commons Math Release Notes covariance) - Added multivariate summary statistics + Added multivariate summary statistics. + + + Added getSumOfLogs method to SummaryStatistics and made SumOfLogs + instance used by GeometricMean configurable.