[commons-numbers] 01/03: NUMBERS-161: Special case.

[er...@apache.org]

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

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

commit 056b268a8e168177c9744744cf2f33f6e9c0376b
Author: Gilles Sadowski <gi...@gmail.com>
AuthorDate: Thu Jun 3 23:01:07 2021 +0200

    NUMBERS-161: Special case.
---
 .../src/main/java/org/apache/commons/numbers/angle/Angle.java | 11 ++++++-----
 .../test/java/org/apache/commons/numbers/angle/AngleTest.java |  6 +++++-
 2 files changed, 11 insertions(+), 6 deletions(-)

diff --git a/commons-numbers-angle/src/main/java/org/apache/commons/numbers/angle/Angle.java b/commons-numbers-angle/src/main/java/org/apache/commons/numbers/angle/Angle.java
index 64ea55e..54dcde9 100644
--- a/commons-numbers-angle/src/main/java/org/apache/commons/numbers/angle/Angle.java
+++ b/commons-numbers-angle/src/main/java/org/apache/commons/numbers/angle/Angle.java
@@ -347,11 +347,12 @@ public abstract class Angle implements DoubleSupplier {
             return normalized < hi ?
                 normalized :
                 // If value is too small to be representable compared to the
-                // floor expression above (ie, if value + x = x), then we may
-                // end up with a number exactly equal to the upper bound here.
-                // In that case, subtract one from the normalized value so that
-                // we can fulfill the contract of only returning results strictly
-                // less than the upper bound.
+                // floor expression above (i.e. value + x = x), then we may
+                // end up with a number exactly equal to the upper bound.
+                // In that case, subtract one period from the normalized value
+                // so that the result is strictly less than the upper bound.
+                normalized == hi ?
+                lo : // Ensure that the result is not below the lower bound.
                 normalized - period;
         }
     }
diff --git a/commons-numbers-angle/src/test/java/org/apache/commons/numbers/angle/AngleTest.java b/commons-numbers-angle/src/test/java/org/apache/commons/numbers/angle/AngleTest.java
index 54ac3e3..92fda4b 100644
--- a/commons-numbers-angle/src/test/java/org/apache/commons/numbers/angle/AngleTest.java
+++ b/commons-numbers-angle/src/test/java/org/apache/commons/numbers/angle/AngleTest.java
@@ -205,6 +205,10 @@ class AngleTest {
 
         Assertions.assertEquals(x, normalizer.apply(Angle.Rad.of(x)).getAsDouble());
         Assertions.assertEquals(above, normalizer.apply(Angle.Rad.of(above)).getAsDouble());
-        // Assertions.assertEquals(below + 2 * Math.PI, normalizer.apply(Angle.Rad.of(below)).getAsDouble());
+
+        // "below" is so close to "x" that below + Math.PI = x + Math.PI
+        // In this case, we can't return below + Math.PI because that is exactly equal to the
+        // upper bound of the range. Instead, we must return the lower bound of x.
+        Assertions.assertEquals(x, normalizer.apply(Angle.Rad.of(below)).getAsDouble());
     }
 }