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Posted to commits@commons.apache.org by tn...@apache.org on 2013/10/21 22:13:52 UTC
svn commit: r1534358 - in
/commons/proper/math/trunk/src/main/java/org/apache/commons/math3/distribution:
BinomialDistribution.java ExponentialDistribution.java FDistribution.java
HypergeometricDistribution.java PoissonDistribution.java TDistribution.java
Author: tn
Date: Mon Oct 21 20:13:52 2013
New Revision: 1534358
URL: http://svn.apache.org/r1534358
Log:
Avoid code duplication in Distribution density/probability methods by using the result of logDensity or logProbability respectively.
Modified:
commons/proper/math/trunk/src/main/java/org/apache/commons/math3/distribution/BinomialDistribution.java
commons/proper/math/trunk/src/main/java/org/apache/commons/math3/distribution/ExponentialDistribution.java
commons/proper/math/trunk/src/main/java/org/apache/commons/math3/distribution/FDistribution.java
commons/proper/math/trunk/src/main/java/org/apache/commons/math3/distribution/HypergeometricDistribution.java
commons/proper/math/trunk/src/main/java/org/apache/commons/math3/distribution/PoissonDistribution.java
commons/proper/math/trunk/src/main/java/org/apache/commons/math3/distribution/TDistribution.java
Modified: commons/proper/math/trunk/src/main/java/org/apache/commons/math3/distribution/BinomialDistribution.java
URL: http://svn.apache.org/viewvc/commons/proper/math/trunk/src/main/java/org/apache/commons/math3/distribution/BinomialDistribution.java?rev=1534358&r1=1534357&r2=1534358&view=diff
==============================================================================
--- commons/proper/math/trunk/src/main/java/org/apache/commons/math3/distribution/BinomialDistribution.java (original)
+++ commons/proper/math/trunk/src/main/java/org/apache/commons/math3/distribution/BinomialDistribution.java Mon Oct 21 20:13:52 2013
@@ -99,15 +99,8 @@ public class BinomialDistribution extend
/** {@inheritDoc} */
public double probability(int x) {
- double ret;
- if (x < 0 || x > numberOfTrials) {
- ret = 0.0;
- } else {
- ret = FastMath.exp(SaddlePointExpansion.logBinomialProbability(x,
- numberOfTrials, probabilityOfSuccess,
- 1.0 - probabilityOfSuccess));
- }
- return ret;
+ final double logProbability = logProbability(x);
+ return logProbability == Double.NEGATIVE_INFINITY ? 0 : FastMath.exp(logProbability);
}
/** {@inheritDoc} **/
Modified: commons/proper/math/trunk/src/main/java/org/apache/commons/math3/distribution/ExponentialDistribution.java
URL: http://svn.apache.org/viewvc/commons/proper/math/trunk/src/main/java/org/apache/commons/math3/distribution/ExponentialDistribution.java?rev=1534358&r1=1534357&r2=1534358&view=diff
==============================================================================
--- commons/proper/math/trunk/src/main/java/org/apache/commons/math3/distribution/ExponentialDistribution.java (original)
+++ commons/proper/math/trunk/src/main/java/org/apache/commons/math3/distribution/ExponentialDistribution.java Mon Oct 21 20:13:52 2013
@@ -161,15 +161,16 @@ public class ExponentialDistribution ext
/** {@inheritDoc} */
public double density(double x) {
- if (x < 0) {
- return 0;
- }
- return FastMath.exp(-x / mean) / mean;
+ final double logDensity = logDensity(x);
+ return logDensity == Double.NEGATIVE_INFINITY ? 0 : FastMath.exp(logDensity);
}
/** {@inheritDoc} **/
@Override
public double logDensity(double x) {
+ if (x < 0) {
+ return Double.NEGATIVE_INFINITY;
+ }
return -x / mean - logMean;
}
Modified: commons/proper/math/trunk/src/main/java/org/apache/commons/math3/distribution/FDistribution.java
URL: http://svn.apache.org/viewvc/commons/proper/math/trunk/src/main/java/org/apache/commons/math3/distribution/FDistribution.java?rev=1534358&r1=1534357&r2=1534358&view=diff
==============================================================================
--- commons/proper/math/trunk/src/main/java/org/apache/commons/math3/distribution/FDistribution.java (original)
+++ commons/proper/math/trunk/src/main/java/org/apache/commons/math3/distribution/FDistribution.java Mon Oct 21 20:13:52 2013
@@ -142,16 +142,7 @@ public class FDistribution extends Abstr
* @since 2.1
*/
public double density(double x) {
- final double nhalf = numeratorDegreesOfFreedom / 2;
- final double mhalf = denominatorDegreesOfFreedom / 2;
- final double logx = FastMath.log(x);
- final double logn = FastMath.log(numeratorDegreesOfFreedom);
- final double logm = FastMath.log(denominatorDegreesOfFreedom);
- final double lognxm = FastMath.log(numeratorDegreesOfFreedom * x +
- denominatorDegreesOfFreedom);
- return FastMath.exp(nhalf * logn + nhalf * logx - logx +
- mhalf * logm - nhalf * lognxm - mhalf * lognxm -
- Beta.logBeta(nhalf, mhalf));
+ return FastMath.exp(logDensity(x));
}
/** {@inheritDoc} **/
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=1534358&r1=1534357&r2=1534358&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 Mon Oct 21 20:13:52 2013
@@ -193,25 +193,8 @@ public class HypergeometricDistribution
/** {@inheritDoc} */
public double probability(int x) {
- double ret;
-
- int[] domain = getDomain(populationSize, numberOfSuccesses, sampleSize);
- if (x < domain[0] || x > domain[1]) {
- ret = 0.0;
- } else {
- double p = (double) sampleSize / (double) populationSize;
- double q = (double) (populationSize - sampleSize) / (double) populationSize;
- double p1 = SaddlePointExpansion.logBinomialProbability(x,
- numberOfSuccesses, p, q);
- double p2 =
- SaddlePointExpansion.logBinomialProbability(sampleSize - x,
- populationSize - numberOfSuccesses, p, q);
- double p3 =
- SaddlePointExpansion.logBinomialProbability(sampleSize, populationSize, p, q);
- ret = FastMath.exp(p1 + p2 - p3);
- }
-
- return ret;
+ final double logProbability = logProbability(x);
+ return logProbability == Double.NEGATIVE_INFINITY ? 0 : FastMath.exp(logProbability);
}
/** {@inheritDoc} */
Modified: commons/proper/math/trunk/src/main/java/org/apache/commons/math3/distribution/PoissonDistribution.java
URL: http://svn.apache.org/viewvc/commons/proper/math/trunk/src/main/java/org/apache/commons/math3/distribution/PoissonDistribution.java?rev=1534358&r1=1534357&r2=1534358&view=diff
==============================================================================
--- commons/proper/math/trunk/src/main/java/org/apache/commons/math3/distribution/PoissonDistribution.java (original)
+++ commons/proper/math/trunk/src/main/java/org/apache/commons/math3/distribution/PoissonDistribution.java Mon Oct 21 20:13:52 2013
@@ -161,17 +161,8 @@ public class PoissonDistribution extends
/** {@inheritDoc} */
public double probability(int x) {
- double ret;
- if (x < 0 || x == Integer.MAX_VALUE) {
- ret = 0.0;
- } else if (x == 0) {
- ret = FastMath.exp(-mean);
- } else {
- ret = FastMath.exp(-SaddlePointExpansion.getStirlingError(x) -
- SaddlePointExpansion.getDeviancePart(x, mean)) /
- FastMath.sqrt(MathUtils.TWO_PI * x);
- }
- return ret;
+ final double logProbability = logProbability(x);
+ return logProbability == Double.NEGATIVE_INFINITY ? 0 : FastMath.exp(logProbability);
}
/** {@inheritDoc} */
Modified: commons/proper/math/trunk/src/main/java/org/apache/commons/math3/distribution/TDistribution.java
URL: http://svn.apache.org/viewvc/commons/proper/math/trunk/src/main/java/org/apache/commons/math3/distribution/TDistribution.java?rev=1534358&r1=1534357&r2=1534358&view=diff
==============================================================================
--- commons/proper/math/trunk/src/main/java/org/apache/commons/math3/distribution/TDistribution.java (original)
+++ commons/proper/math/trunk/src/main/java/org/apache/commons/math3/distribution/TDistribution.java Mon Oct 21 20:13:52 2013
@@ -120,13 +120,7 @@ public class TDistribution extends Abstr
/** {@inheritDoc} */
public double density(double x) {
- final double n = degreesOfFreedom;
- final double nPlus1Over2 = (n + 1) / 2;
- return FastMath.exp(Gamma.logGamma(nPlus1Over2) -
- 0.5 * (FastMath.log(FastMath.PI) +
- FastMath.log(n)) -
- Gamma.logGamma(n / 2) -
- nPlus1Over2 * FastMath.log(1 + x * x / n));
+ return FastMath.exp(logDensity(x));
}
/** {@inheritDoc} */