[commons-statistics] 02/35: Added test for default methods in ContinuousDistribution

[ah...@apache.org]

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

commit c4544b7f3b91ba96e1dc3a659338506dc4410ee3
Author: aherbert <ah...@apache.org>
AuthorDate: Tue Jun 23 12:20:37 2020 +0100

    Added test for default methods in ContinuousDistribution
---
 .../distribution/ContinuousDistributionTest.java   | 89 ++++++++++++++++++++++
 1 file changed, 89 insertions(+)

diff --git a/commons-statistics-distribution/src/test/java/org/apache/commons/statistics/distribution/ContinuousDistributionTest.java b/commons-statistics-distribution/src/test/java/org/apache/commons/statistics/distribution/ContinuousDistributionTest.java
new file mode 100644
index 0000000..8f1281f
--- /dev/null
+++ b/commons-statistics-distribution/src/test/java/org/apache/commons/statistics/distribution/ContinuousDistributionTest.java
@@ -0,0 +1,89 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.apache.commons.statistics.distribution;
+
+import org.apache.commons.rng.UniformRandomProvider;
+import org.junit.jupiter.api.Assertions;
+import org.junit.jupiter.api.Test;
+
+/**
+ * Test default implementations in the {@link ContinuousDistribution} interface.
+ */
+public class ContinuousDistributionTest {
+    /**
+     * Test the default interface methods
+     */
+    @Test
+    public void testDefaultMethods() {
+        final double high = 0.54;
+        final double low = 0.313;
+
+        final ContinuousDistribution dist = new ContinuousDistribution() {
+            @Override
+            public boolean isSupportConnected() {
+                return false;
+            }
+            @Override
+            public double inverseCumulativeProbability(double p) {
+                return 0;
+            }
+            @Override
+            public double getVariance() {
+                return 0;
+            }
+            @Override
+            public double getSupportUpperBound() {
+                return 0;
+            }
+            @Override
+            public double getSupportLowerBound() {
+                return 0;
+            }
+            @Override
+            public double getMean() {
+                return 0;
+            }
+            @Override
+            public double density(double x) {
+                // Return input value for testing
+                return x;
+            }
+            @Override
+            public double cumulativeProbability(double x) {
+                // For the default probability(double, double) method
+                return x > 1 ? high : low;
+            }
+            @Override
+            public Sampler createSampler(UniformRandomProvider rng) {
+                return null;
+            }
+        };
+
+        for (final double x : new double[] {Double.NaN, Double.POSITIVE_INFINITY,
+            Double.NEGATIVE_INFINITY, 0, 1, 0.123}) {
+            // Always zero
+            Assertions.assertEquals(0, dist.probability(x));
+
+            // Return the log of the density
+            Assertions.assertEquals(Math.log(x), dist.logDensity(x));
+        }
+
+        // Should throw for bad range
+        Assertions.assertThrows(DistributionException.class, () -> dist.probability(0.5, 0.4));
+        Assertions.assertEquals(high - low, dist.probability(0.5, 1.5));
+    }
+}