fix a bug that sometimes Binomial test return probability greater than 1
Project: http://git-wip-us.apache.org/repos/asf/commons-math/repo Commit: http://git-wip-us.apache.org/repos/asf/commons-math/commit/9df5e941 Tree: http://git-wip-us.apache.org/repos/asf/commons-math/tree/9df5e941 Diff: http://git-wip-us.apache.org/repos/asf/commons-math/diff/9df5e941 Branch: refs/heads/master Commit: 9df5e9419d83c11b4a2c3421c5ff7ea1f544366b Parents: 53ec46b Author: Kexin Xie <[email protected]> Authored: Sun May 7 09:47:14 2017 -0700 Committer: Bruno P. Kinoshita <[email protected]> Committed: Tue May 9 15:06:52 2017 +1200 ---------------------------------------------------------------------- .../math4/stat/inference/BinomialTest.java | 6 ++- .../math4/stat/inference/BinomialTestTest.java | 48 ++++++++++++++++++++ 2 files changed, 53 insertions(+), 1 deletion(-) ---------------------------------------------------------------------- http://git-wip-us.apache.org/repos/asf/commons-math/blob/9df5e941/src/main/java/org/apache/commons/math4/stat/inference/BinomialTest.java ---------------------------------------------------------------------- diff --git a/src/main/java/org/apache/commons/math4/stat/inference/BinomialTest.java b/src/main/java/org/apache/commons/math4/stat/inference/BinomialTest.java index 2846c68..4a94130 100644 --- a/src/main/java/org/apache/commons/math4/stat/inference/BinomialTest.java +++ b/src/main/java/org/apache/commons/math4/stat/inference/BinomialTest.java @@ -135,7 +135,11 @@ public class BinomialTest { double pHigh = distribution.probability(criticalValueHigh); if (pLow == pHigh) { - pTotal += 2 * pLow; + if (criticalValueLow == criticalValueHigh) { + pTotal += pLow; + } else { + pTotal += 2 * pLow; + } criticalValueLow++; criticalValueHigh--; } else if (pLow < pHigh) { http://git-wip-us.apache.org/repos/asf/commons-math/blob/9df5e941/src/test/java/org/apache/commons/math4/stat/inference/BinomialTestTest.java ---------------------------------------------------------------------- diff --git a/src/test/java/org/apache/commons/math4/stat/inference/BinomialTestTest.java b/src/test/java/org/apache/commons/math4/stat/inference/BinomialTestTest.java index 365f21d..55e1730 100644 --- a/src/test/java/org/apache/commons/math4/stat/inference/BinomialTestTest.java +++ b/src/test/java/org/apache/commons/math4/stat/inference/BinomialTestTest.java @@ -42,6 +42,54 @@ public class BinomialTestTest { trials, successes, probability, AlternativeHypothesis.GREATER_THAN), 1E-4); Assert.assertEquals(0.982, testStatistic.binomialTest( trials, successes, probability, AlternativeHypothesis.LESS_THAN), 1E-4); + + // for special boundary conditions + Assert.assertEquals(1, testStatistic.binomialTest( + 3, 3, 1, AlternativeHypothesis.TWO_SIDED), 1E-4); + Assert.assertEquals(1, testStatistic.binomialTest( + 3, 3, 0.9, AlternativeHypothesis.TWO_SIDED), 1E-4); + Assert.assertEquals(1, testStatistic.binomialTest( + 3, 3, 0.8, AlternativeHypothesis.TWO_SIDED), 1E-4); + Assert.assertEquals(0.559, testStatistic.binomialTest( + 3, 3, 0.7, AlternativeHypothesis.TWO_SIDED), 1E-4); + Assert.assertEquals(0.28, testStatistic.binomialTest( + 3, 3, 0.6, AlternativeHypothesis.TWO_SIDED), 1E-4); + Assert.assertEquals(0.25, testStatistic.binomialTest( + 3, 3, 0.5, AlternativeHypothesis.TWO_SIDED), 1E-4); + Assert.assertEquals(0.064, testStatistic.binomialTest( + 3, 3, 0.4, AlternativeHypothesis.TWO_SIDED), 1E-4); + Assert.assertEquals(0.027, testStatistic.binomialTest( + 3, 3, 0.3, AlternativeHypothesis.TWO_SIDED), 1E-4); + Assert.assertEquals(0.008, testStatistic.binomialTest( + 3, 3, 0.2, AlternativeHypothesis.TWO_SIDED), 1E-4); + Assert.assertEquals(0.001, testStatistic.binomialTest( + 3, 3, 0.1, AlternativeHypothesis.TWO_SIDED), 1E-4); + Assert.assertEquals(0, testStatistic.binomialTest( + 3, 3, 0.0, AlternativeHypothesis.TWO_SIDED), 1E-4); + + Assert.assertEquals(0, testStatistic.binomialTest( + 3, 0, 1, AlternativeHypothesis.TWO_SIDED), 1E-4); + Assert.assertEquals(0.001, testStatistic.binomialTest( + 3, 0, 0.9, AlternativeHypothesis.TWO_SIDED), 1E-4); + Assert.assertEquals(0.008, testStatistic.binomialTest( + 3, 0, 0.8, AlternativeHypothesis.TWO_SIDED), 1E-4); + Assert.assertEquals(0.027, testStatistic.binomialTest( + 3, 0, 0.7, AlternativeHypothesis.TWO_SIDED), 1E-4); + Assert.assertEquals(0.064, testStatistic.binomialTest( + 3, 0, 0.6, AlternativeHypothesis.TWO_SIDED), 1E-4); + Assert.assertEquals(0.25, testStatistic.binomialTest( + 3, 0, 0.5, AlternativeHypothesis.TWO_SIDED), 1E-4); + Assert.assertEquals(0.28, testStatistic.binomialTest( + 3, 0, 0.4, AlternativeHypothesis.TWO_SIDED), 1E-4); + Assert.assertEquals(0.559, testStatistic.binomialTest( + 3, 0, 0.3, AlternativeHypothesis.TWO_SIDED), 1E-4); + Assert.assertEquals(1, testStatistic.binomialTest( + 3, 0, 0.2, AlternativeHypothesis.TWO_SIDED), 1E-4); + Assert.assertEquals(1, testStatistic.binomialTest( + 3, 0, 0.1, AlternativeHypothesis.TWO_SIDED), 1E-4); + Assert.assertEquals(1, testStatistic.binomialTest( + 3, 0, 0.0, AlternativeHypothesis.TWO_SIDED), 1E-4); + } @Test
