commit cbc4298809b24af9144d6024d593dbb1963d42d4
author aherbert <aherbert@apache.org> Fri Jul 30 15:26:36 2021 +0100
committer aherbert <aherbert@apache.org> Fri Jul 30 15:26:36 2021 +0100
tree 93480d77c1836d327aaf691e7b8ee5c8512b060c
parent d9629f9c3b9bf1faf7ffb263d1756a2c3239f087

Fix inverseCumulativeProbability

commons-statistics-distribution/src/main/java/org/apache/commons/statistics/distribution/LogisticDistribution.java

diff --git a/commons-statistics-distribution/src/main/java/org/apache/commons/statistics/distribution/LogisticDistribution.java b/commons-statistics-distribution/src/main/java/org/apache/commons/statistics/distribution/LogisticDistribution.java
index 522ccda..7bbdebd 100644
--- a/commons-statistics-distribution/src/main/java/org/apache/commons/statistics/distribution/LogisticDistribution.java
+++ b/commons-statistics-distribution/src/main/java/org/apache/commons/statistics/distribution/LogisticDistribution.java
@@ -104,9 +104,9 @@
             p > 1) {
             throw new DistributionException(DistributionException.INVALID_PROBABILITY, p);
         } else if (p == 0) {
-            return 0;
+            return SUPPORT_LO;
         } else if (p == 1) {
-            return Double.POSITIVE_INFINITY;
+            return SUPPORT_HI;
         } else {
             return scale * Math.log(p / (1 - p)) + mu;
         }

commons-statistics-distribution/src/test/java/org/apache/commons/statistics/distribution/LogisticDistributionTest.java

diff --git a/commons-statistics-distribution/src/test/java/org/apache/commons/statistics/distribution/LogisticDistributionTest.java b/commons-statistics-distribution/src/test/java/org/apache/commons/statistics/distribution/LogisticDistributionTest.java
index 60e7cfe..a6d1de5 100644
--- a/commons-statistics-distribution/src/test/java/org/apache/commons/statistics/distribution/LogisticDistributionTest.java
+++ b/commons-statistics-distribution/src/test/java/org/apache/commons/statistics/distribution/LogisticDistributionTest.java
@@ -81,7 +81,7 @@
     @Test
     void testInverseCumulativeProbabilityExtremes() {
         setInverseCumulativeTestPoints(new double[] {0, 1});
-        setInverseCumulativeTestValues(new double[] {0, Double.POSITIVE_INFINITY});
+        setInverseCumulativeTestValues(new double[] {Double.NEGATIVE_INFINITY, Double.POSITIVE_INFINITY});
         verifyInverseCumulativeProbabilities();
     }