fix to issue 374 (#376)

Author: sudiptoguha

Java/benchmark/pom.xml

@@ -6,7 +6,7 @@
   <parent>
     <groupId>software.amazon.randomcutforest</groupId>
     <artifactId>randomcutforest-parent</artifactId>
-    <version>3.5.1-SNAPSHOT</version>
+    <version>3.5.1</version>
   </parent>
 
   <artifactId>randomcutforest-benchmark</artifactId>

Java/core/pom.xml

@@ -6,7 +6,7 @@
   <parent>
     <groupId>software.amazon.randomcutforest</groupId>
     <artifactId>randomcutforest-parent</artifactId>
-    <version>3.5.1-SNAPSHOT</version>
+    <version>3.5.1</version>
   </parent>
 
   <artifactId>randomcutforest-core</artifactId>

Java/core/src/main/java/com/amazon/randomcutforest/tree/RandomCutTree.java

@@ -123,13 +123,18 @@ public void setBoundingBoxCacheFraction(double fraction) {
 
     /**
      * Return a new {@link Cut}, which is chosen uniformly over the space of
-     * possible cuts for the given bounding box.
+     * possible cuts for a bounding box and its union with a point. The cut must
+     * exist unless the union box is a single point. There are floating point issues
+     * -- even though the original values are in float anf the calculations are in
+     * double, which can show up with large number of dimensions (each trigerring an
+     * addition/substraction).
      *
      * @param factor A random cut
+     * @param point  the point whose union is taken with the box
      * @param box    A bounding box that we want to find a random cut for.
      * @return A new Cut corresponding to a random cut in the bounding box.
      */
-    protected Cut randomCut(double factor, float[] point, BoundingBox box) {
+    protected static Cut randomCut(double factor, float[] point, BoundingBox box) {
         double range = 0.0;
 
         for (int i = 0; i < point.length; i++) {
@@ -143,6 +148,9 @@ protected Cut randomCut(double factor, float[] point, BoundingBox box) {
             range += maxValue - minValue;
         }
 
+        checkArgument(range > 0, " the union is a single point " + Arrays.toString(point)
+                + "or the box is inappropriate, box" + box.toString() + "factor =" + factor);
+
         double breakPoint = factor * range;
 
         for (int i = 0; i < box.getDimensions(); i++) {
@@ -169,7 +177,50 @@ protected Cut randomCut(double factor, float[] point, BoundingBox box) {
             breakPoint -= gap;
         }
 
-        throw new IllegalStateException("The break point did not lie inside the expected range");
+        // if we are here then factor is likely almost 1 and we have floating point
+        // issues
+        // we will randomize between the first and the last non-zero ranges and choose
+        // the
+        // same cutValue as using nextAfter above -- we will use the factor as a seed
+        // and
+        // not be optimizing this sequel (either in execution or code) to ensure easier
+        // debugging
+        // this should be an anomaly - no pun intended.
+
+        Random rng = new Random((long) factor);
+        if (rng.nextDouble() < 0.5) {
+            for (int i = 0; i < box.getDimensions(); i++) {
+                float minValue = (float) box.getMinValue(i);
+                float maxValue = (float) box.getMaxValue(i);
+                if (point[i] < minValue) {
+                    minValue = point[i];
+                } else if (point[i] > maxValue) {
+                    maxValue = point[i];
+                }
+                if (maxValue > minValue) {
+                    double cutValue = Math.nextAfter((float) maxValue, minValue);
+                    return new Cut(i, cutValue);
+                }
+            }
+        } else {
+            for (int i = box.getDimensions() - 1; i >= 0; i--) {
+                float minValue = (float) box.getMinValue(i);
+                float maxValue = (float) box.getMaxValue(i);
+                if (point[i] < minValue) {
+                    minValue = point[i];
+                } else if (point[i] > maxValue) {
+                    maxValue = point[i];
+                }
+                if (maxValue > minValue) {
+                    double cutValue = Math.nextAfter((float) maxValue, minValue);
+                    return new Cut(i, cutValue);
+                }
+            }
+        }
+
+        throw new IllegalStateException("The break point did not lie inside the expected range; factor " + factor
+                + ", point " + Arrays.toString(point) + " box " + box.toString());
+
     }
 
     public Integer addPoint(Integer pointIndex, long sequenceIndex) {

Java/core/src/test/java/com/amazon/randomcutforest/RandomCutForestTest.java

@@ -890,11 +890,13 @@ public void testFloatingPointRandomCut() {
         int dimensions = 16;
         int numberOfTrees = 41;
         int sampleSize = 64;
+        long seed = new Random().nextLong();
+        System.out.println(" seed " + seed);
         int dataSize = 4000 * sampleSize;
         double[][] big = generateShingledData(dataSize, dimensions, 2);
         RandomCutForest forest = RandomCutForest.builder().compact(true).dimensions(dimensions)
-                .numberOfTrees(numberOfTrees).sampleSize(sampleSize).precision(Precision.FLOAT_32)
-                .randomSeed(2051627799894425983L).boundingBoxCacheFraction(1.0).build();
+                .numberOfTrees(numberOfTrees).sampleSize(sampleSize).precision(Precision.FLOAT_32).randomSeed(seed)
+                .boundingBoxCacheFraction(1.0).build();
 
         int num = 0;
         for (double[] point : big) {

Java/core/src/test/java/com/amazon/randomcutforest/tree/RandomCutTreeTest.java

@@ -366,4 +366,32 @@ public void testUpdatesOnSmallBoundingBox() {
             tree.addPoint(i % points.size(), point.getSequenceIndex());
         }
     }
+
+    @Test
+    public void testfloat() {
+        float x = 110.13f;
+        double sum = 0;
+        int trials = 230000;
+        for (int i = 0; i < trials; i++) {
+            float z = (x * (trials - i + 1) - x);
+            sum += z;
+        }
+        System.out.println(sum);
+        for (int i = 0; i < trials - 1; i++) {
+            float z = (x * (trials - i + 1) - x);
+            sum -= z;
+        }
+        System.out.println(sum + " " + (double) x + " " + (sum <= (double) x));
+        float[] possible = new float[trials];
+        float[] alsoPossible = new float[trials];
+        for (int i = 0; i < trials; i++) {
+            possible[i] = x;
+            alsoPossible[i] = (trials - i + 1) * x;
+        }
+        BoundingBox box = new BoundingBox(possible, alsoPossible);
+        System.out.println("rangesum " + box.getRangeSum());
+        double factor = 1.0 - 1e-16;
+        System.out.println(factor);
+        Cut cut = RandomCutTree.randomCut(factor, possible, box);
+    }
 }

Java/examples/pom.xml

@@ -7,7 +7,7 @@
     <parent>
         <groupId>software.amazon.randomcutforest</groupId>
         <artifactId>randomcutforest-parent</artifactId>
-        <version>3.5.1-SNAPSHOT</version>
+        <version>3.5.1</version>
     </parent>
 
     <artifactId>randomcutforest-examples</artifactId>

Java/parkservices/pom.xml

@@ -6,7 +6,7 @@
   <parent>
     <groupId>software.amazon.randomcutforest</groupId>
     <artifactId>randomcutforest-parent</artifactId>
-    <version>3.5.1-SNAPSHOT</version>
+    <version>3.5.1</version>
   </parent>
 
   <artifactId>randomcutforest-parkservices</artifactId>

Java/pom.xml

@@ -4,7 +4,7 @@
 
     <groupId>software.amazon.randomcutforest</groupId>
     <artifactId>randomcutforest-parent</artifactId>
-    <version>3.5.1-SNAPSHOT</version>
+    <version>3.5.1</version>
     <packaging>pom</packaging>
 
     <name>software.amazon.randomcutforest:randomcutforest</name>

Java/serialization/pom.xml

@@ -7,7 +7,7 @@
     <parent>
         <groupId>software.amazon.randomcutforest</groupId>
         <artifactId>randomcutforest-parent</artifactId>
-        <version>3.5.1-SNAPSHOT</version>
+        <version>3.5.1</version>
     </parent>
 
     <artifactId>randomcutforest-serialization</artifactId>

Java/testutils/pom.xml

@@ -4,7 +4,7 @@
   <parent>
     <artifactId>randomcutforest-parent</artifactId>
     <groupId>software.amazon.randomcutforest</groupId>
-    <version>3.5.1-SNAPSHOT</version>
+    <version>3.5.1</version>
   </parent>
 
   <artifactId>randomcutforest-testutils</artifactId>