Author: erans
Date: Sat Aug 10 00:57:48 2013
New Revision: 1512546
URL: http://svn.apache.org/r1512546
Log:
MATH-1021
Reordering can prevent some overflow occurrences (fix suggested by
Brian Bloniarz).
Added unit test.
Modified:
commons/proper/math/trunk/pom.xml
commons/proper/math/trunk/src/changes/changes.xml
commons/proper/math/trunk/src/main/java/org/apache/commons/math3/distribution/HypergeometricDistribution.java
commons/proper/math/trunk/src/test/java/org/apache/commons/math3/distribution/HypergeometricDistributionTest.java
Modified: commons/proper/math/trunk/pom.xml
URL:
http://svn.apache.org/viewvc/commons/proper/math/trunk/pom.xml?rev=1512546&r1=1512545&r2=1512546&view=diff
==============================================================================
--- commons/proper/math/trunk/pom.xml (original)
+++ commons/proper/math/trunk/pom.xml Sat Aug 10 00:57:48 2013
@@ -151,6 +151,9 @@
<name>Michael Bjorkegren</name>
</contributor>
<contributor>
+ <name>Brian Bloniarz</name>
+ </contributor>
+ <contributor>
<name>John Bollinger</name>
</contributor>
<contributor>
Modified: commons/proper/math/trunk/src/changes/changes.xml
URL:
http://svn.apache.org/viewvc/commons/proper/math/trunk/src/changes/changes.xml?rev=1512546&r1=1512545&r2=1512546&view=diff
==============================================================================
--- commons/proper/math/trunk/src/changes/changes.xml (original)
+++ commons/proper/math/trunk/src/changes/changes.xml Sat Aug 10 00:57:48 2013
@@ -51,6 +51,9 @@ If the output is not quite correct, chec
</properties>
<body>
<release version="x.y" date="TBD" description="TBD">
+ <action dev="erans" type="fix" issue="MATH-1021" due-to="Brian Bloniarz">
+ Fixed overflow in "HypergeometricDistribution".
+ </action>
<action dev="erans" type="fix" issue="MATH-1020">
Fixed "nextPermutation" method (in
"o.a.c.m.random.RandomDataGenerator").
This bug does not affect applications using a previous version of
Modified:
commons/proper/math/trunk/src/main/java/org/apache/commons/math3/distribution/HypergeometricDistribution.java
URL:
http://svn.apache.org/viewvc/commons/proper/math/trunk/src/main/java/org/apache/commons/math3/distribution/HypergeometricDistribution.java?rev=1512546&r1=1512545&r2=1512546&view=diff
==============================================================================
---
commons/proper/math/trunk/src/main/java/org/apache/commons/math3/distribution/HypergeometricDistribution.java
(original)
+++
commons/proper/math/trunk/src/main/java/org/apache/commons/math3/distribution/HypergeometricDistribution.java
Sat Aug 10 00:57:48 2013
@@ -265,7 +265,7 @@ public class HypergeometricDistribution
* size {@code n}, the mean is {@code n * m / N}.
*/
public double getNumericalMean() {
- return (double) (getSampleSize() * getNumberOfSuccesses()) / (double)
getPopulationSize();
+ return getSampleSize() * (getNumberOfSuccesses() / (double)
getPopulationSize());
}
/**
Modified:
commons/proper/math/trunk/src/test/java/org/apache/commons/math3/distribution/HypergeometricDistributionTest.java
URL:
http://svn.apache.org/viewvc/commons/proper/math/trunk/src/test/java/org/apache/commons/math3/distribution/HypergeometricDistributionTest.java?rev=1512546&r1=1512545&r2=1512546&view=diff
==============================================================================
---
commons/proper/math/trunk/src/test/java/org/apache/commons/math3/distribution/HypergeometricDistributionTest.java
(original)
+++
commons/proper/math/trunk/src/test/java/org/apache/commons/math3/distribution/HypergeometricDistributionTest.java
Sat Aug 10 00:57:48 2013
@@ -284,4 +284,18 @@ public class HypergeometricDistributionT
double upper = 1.0 - dist.cumulativeProbability(k) +
dist.probability(k);
Assert.assertTrue(Precision.compareTo(1.0, upper, 1) == 0);
}
+
+ @Test
+ public void testMath1021() {
+ final int N = 43130568;
+ final int m = 42976365;
+ final int n = 50;
+ final HypergeometricDistribution dist = new
HypergeometricDistribution(N, m, n);
+
+ for (int i = 0; i < 100; i++) {
+ final int sample = dist.sample();
+ Assert.assertTrue("sample=" + sample, 0 <= sample);
+ Assert.assertTrue("sample=" + sample, sample <= n);
+ }
+ }
}
