[commons-statistics] 20/22: Add edge case coverage for density

[aherbert]

This is an automated email from the ASF dual-hosted git repository.

aherbert pushed a commit to branch master
in repository https://gitbox.apache.org/repos/asf/commons-statistics.git

commit 877eb70d7ae9b6971b360d46dcfcb16681676a07
Author: aherbert <aherb...@apache.org>
AuthorDate: Fri Jul 30 16:44:09 2021 +0100

    Add edge case coverage for density
---
 .../commons/statistics/distribution/GammaDistributionTest.java     | 7 +++++++
 .../commons/statistics/distribution/LevyDistributionTest.java      | 7 +++++++
 .../commons/statistics/distribution/WeibullDistributionTest.java   | 7 +++++++
 3 files changed, 21 insertions(+)

diff --git 
a/commons-statistics-distribution/src/test/java/org/apache/commons/statistics/distribution/GammaDistributionTest.java
 
b/commons-statistics-distribution/src/test/java/org/apache/commons/statistics/distribution/GammaDistributionTest.java
index b7eb220..691d8b1 100644
--- 
a/commons-statistics-distribution/src/test/java/org/apache/commons/statistics/distribution/GammaDistributionTest.java
+++ 
b/commons-statistics-distribution/src/test/java/org/apache/commons/statistics/distribution/GammaDistributionTest.java
@@ -94,6 +94,13 @@ class GammaDistributionTest extends 
ContinuousDistributionAbstractTest {
     //-------------------- Additional test cases 
-------------------------------
 
     @Test
+    void testDensityAtSupportBounds() {
+        final GammaDistribution distribution = makeDistribution();
+        Assertions.assertEquals(0.0, distribution.density(0));
+        Assertions.assertEquals(0.0, 
distribution.density(Double.POSITIVE_INFINITY));
+    }
+
+    @Test
     void testParameterAccessors() {
         final GammaDistribution distribution = makeDistribution();
         Assertions.assertEquals(4d, distribution.getShape());
diff --git 
a/commons-statistics-distribution/src/test/java/org/apache/commons/statistics/distribution/LevyDistributionTest.java
 
b/commons-statistics-distribution/src/test/java/org/apache/commons/statistics/distribution/LevyDistributionTest.java
index 01cedcb..c85632c 100644
--- 
a/commons-statistics-distribution/src/test/java/org/apache/commons/statistics/distribution/LevyDistributionTest.java
+++ 
b/commons-statistics-distribution/src/test/java/org/apache/commons/statistics/distribution/LevyDistributionTest.java
@@ -87,6 +87,13 @@ class LevyDistributionTest extends 
ContinuousDistributionAbstractTest {
     //-------------------- Additional test cases 
-------------------------------
 
     @Test
+    void testDensityAtSupportBounds() {
+        final LevyDistribution distribution = makeDistribution();
+        // Below the location
+        Assertions.assertEquals(0.0, 
distribution.density(distribution.getLocation() - 1));
+    }
+
+    @Test
     void testParameterAccessors() {
         final LevyDistribution d = makeDistribution();
         Assertions.assertEquals(1.2, d.getLocation());
diff --git 
a/commons-statistics-distribution/src/test/java/org/apache/commons/statistics/distribution/WeibullDistributionTest.java
 
b/commons-statistics-distribution/src/test/java/org/apache/commons/statistics/distribution/WeibullDistributionTest.java
index aa076ba..ee4da66 100644
--- 
a/commons-statistics-distribution/src/test/java/org/apache/commons/statistics/distribution/WeibullDistributionTest.java
+++ 
b/commons-statistics-distribution/src/test/java/org/apache/commons/statistics/distribution/WeibullDistributionTest.java
@@ -84,6 +84,13 @@ class WeibullDistributionTest extends 
ContinuousDistributionAbstractTest {
     //-------------------- Additional test cases 
-------------------------------
 
     @Test
+    void testDensityAtSupportBounds() {
+        final WeibullDistribution distribution = makeDistribution();
+        Assertions.assertEquals(0.0, distribution.density(0));
+        Assertions.assertEquals(0.0, 
distribution.density(Double.POSITIVE_INFINITY));
+    }
+
+    @Test
     void testInverseCumulativeProbabilitySmallPAccuracy() {
         final WeibullDistribution dist = new WeibullDistribution(2, 3);
         final double t = dist.inverseCumulativeProbability(1e-17);