TEXT-157: Remove rounding from JaccardSimilarity and Distance

Author: aherbert

src/changes/changes.xml

@@ -54,6 +54,7 @@ The <action> type attribute can be add,update,fix,remove.
     <action issue="TEXT-152" type="add" dev="" due-to="@CAPS50">Fix possible infinite loop in WordUtils.wrap for a regex pattern that would trigger on a match of 0 length</action>
     <action issue="TEXT-153" type="update" dev="" due-to="amirhadadi">Make prefixSet in LookupTranslator a BitSet</action>
     <action issue="TEXT-156" type="update" dev="aherbert">Fix the RegexTokenizer to use a static Pattern</action>
+    <action issue="TEXT-157" type="update" dev="aherbert">Remove rounding from JaccardDistance and JaccardSimilarity</action>
   </release>
 
   <release version="1.6" date="2018-10-12" description="Release 1.6">

src/main/java/org/apache/commons/text/similarity/JaccardDistance.java

@@ -50,6 +50,6 @@ public Double apply(final CharSequence left, final CharSequence right) {
         if (left == null || right == null) {
             throw new IllegalArgumentException("Input cannot be null");
         }
-        return Math.round((1 - jaccardSimilarity.apply(left, right)) * 100d) / 100d;
+        return 1.0 - jaccardSimilarity.apply(left, right).doubleValue();
     }
 }

src/main/java/org/apache/commons/text/similarity/JaccardSimilarity.java

@@ -48,7 +48,7 @@ public Double apply(final CharSequence left, final CharSequence right) {
         if (left == null || right == null) {
             throw new IllegalArgumentException("Input cannot be null");
         }
-        return Math.round(calculateJaccardSimilarity(left, right) * 100d) / 100d;
+        return calculateJaccardSimilarity(left, right);
     }
 
     /**

src/test/java/org/apache/commons/text/similarity/JaccardDistanceTest.java

@@ -36,21 +36,23 @@ public static void setUp() {
 
     @Test
     public void testGettingJaccardDistance() {
-        assertEquals(1.00d, classBeingTested.apply("", ""), 0.00000000000000000001d);
-        assertEquals(1.00d, classBeingTested.apply("left", ""), 0.00000000000000000001d);
-        assertEquals(1.00d, classBeingTested.apply("", "right"), 0.00000000000000000001d);
-        assertEquals(0.25d, classBeingTested.apply("frog", "fog"), 0.00000000000000000001d);
-        assertEquals(1.00d, classBeingTested.apply("fly", "ant"), 0.00000000000000000001d);
-        assertEquals(0.78d, classBeingTested.apply("elephant", "hippo"), 0.00000000000000000001d);
-        assertEquals(0.36d, classBeingTested.apply("ABC Corporation", "ABC Corp"), 0.00000000000000000001d);
-        assertEquals(0.24d, classBeingTested.apply("D N H Enterprises Inc", "D & H Enterprises, Inc."),
-                0.00000000000000000001d);
-        assertEquals(0.11d, classBeingTested.apply("My Gym Children's Fitness Center", "My Gym. Childrens Fitness"),
-                0.00000000000000000001d);
-        assertEquals(0.10d, classBeingTested.apply("PENNSYLVANIA", "PENNCISYLVNIA"), 0.00000000000000000001d);
-        assertEquals(0.87d, classBeingTested.apply("left", "right"), 0.00000000000000000001d);
-        assertEquals(0.87d, classBeingTested.apply("leettteft", "ritttght"), 0.00000000000000000001d);
-        assertEquals(0.0d, classBeingTested.apply("the same string", "the same string"), 0.00000000000000000001d);
+        // Results generated using the python distance library using:
+        // distance.jaccard(seq1, seq2)
+        assertEquals(1.0, classBeingTested.apply("", ""));
+        assertEquals(1.0, classBeingTested.apply("left", ""));
+        assertEquals(1.0, classBeingTested.apply("", "right"));
+        assertEquals(0.25, classBeingTested.apply("frog", "fog"));
+        assertEquals(1.0, classBeingTested.apply("fly", "ant"));
+        assertEquals(0.7777777777777778, classBeingTested.apply("elephant", "hippo"));
+        assertEquals(0.36363636363636365, classBeingTested.apply("ABC Corporation", "ABC Corp"));
+        assertEquals(0.23529411764705888,
+                classBeingTested.apply("D N H Enterprises Inc", "D & H Enterprises, Inc."));
+        assertEquals(0.11111111111111116,
+                classBeingTested.apply("My Gym Children's Fitness Center", "My Gym. Childrens Fitness"));
+        assertEquals(0.09999999999999998, classBeingTested.apply("PENNSYLVANIA", "PENNCISYLVNIA"));
+        assertEquals(0.875, classBeingTested.apply("left", "right"));
+        assertEquals(0.875, classBeingTested.apply("leettteft", "ritttght"));
+        assertEquals(0.0, classBeingTested.apply("the same string", "the same string"));
     }
 
     @Test

src/test/java/org/apache/commons/text/similarity/JaccardSimilarityTest.java

@@ -36,21 +36,23 @@ public static void setUp() {
 
     @Test
     public void testGettingJaccardSimilarity() {
-        assertEquals(0.00d, classBeingTested.apply("", ""), 0.00000000000000000001d);
-        assertEquals(0.00d, classBeingTested.apply("left", ""), 0.00000000000000000001d);
-        assertEquals(0.00d, classBeingTested.apply("", "right"), 0.00000000000000000001d);
-        assertEquals(0.75d, classBeingTested.apply("frog", "fog"), 0.00000000000000000001d);
-        assertEquals(0.00d, classBeingTested.apply("fly", "ant"), 0.00000000000000000001d);
-        assertEquals(0.22d, classBeingTested.apply("elephant", "hippo"), 0.00000000000000000001d);
-        assertEquals(0.64d, classBeingTested.apply("ABC Corporation", "ABC Corp"), 0.00000000000000000001d);
-        assertEquals(0.76d, classBeingTested.apply("D N H Enterprises Inc", "D & H Enterprises, Inc."),
-                0.00000000000000000001d);
-        assertEquals(0.89d, classBeingTested.apply("My Gym Children's Fitness Center", "My Gym. Childrens Fitness"),
-                0.00000000000000000001d);
-        assertEquals(0.9d, classBeingTested.apply("PENNSYLVANIA", "PENNCISYLVNIA"), 0.00000000000000000001d);
-        assertEquals(0.13d, classBeingTested.apply("left", "right"), 0.00000000000000000001d);
-        assertEquals(0.13d, classBeingTested.apply("leettteft", "ritttght"), 0.00000000000000000001d);
-        assertEquals(1.0d, classBeingTested.apply("the same string", "the same string"), 0.00000000000000000001d);
+        // Results generated using the python distance library using:
+        // 1 - distance.jaccard(seq1, seq2)
+        assertEquals(0.0, classBeingTested.apply("", ""));
+        assertEquals(0.0, classBeingTested.apply("left", ""));
+        assertEquals(0.0, classBeingTested.apply("", "right"));
+        assertEquals(0.75, classBeingTested.apply("frog", "fog"));
+        assertEquals(0.0, classBeingTested.apply("fly", "ant"));
+        assertEquals(0.2222222222222222, classBeingTested.apply("elephant", "hippo"));
+        assertEquals(0.6363636363636364, classBeingTested.apply("ABC Corporation", "ABC Corp"));
+        assertEquals(0.7647058823529411,
+                classBeingTested.apply("D N H Enterprises Inc", "D & H Enterprises, Inc."));
+        assertEquals(0.8888888888888888,
+                classBeingTested.apply("My Gym Children's Fitness Center", "My Gym. Childrens Fitness"));
+        assertEquals(0.9, classBeingTested.apply("PENNSYLVANIA", "PENNCISYLVNIA"));
+        assertEquals(0.125, classBeingTested.apply("left", "right"));
+        assertEquals(0.125, classBeingTested.apply("leettteft", "ritttght"));
+        assertEquals(1.0, classBeingTested.apply("the same string", "the same string"));
     }
 
     @Test