[SPARK-5119] java.lang.ArrayIndexOutOfBoundsException on trying to train...

... decision tree model

Labels loaded from libsvm files are mapped to 0.0 if they are negative labels because they should be nonnegative value.

Author: lewuathe <lewuathe@me.com>

Closes #3975 from Lewuathe/map-negative-label-to-positive and squashes the following commits:

12d1d59 [lewuathe] [SPARK-5119] Fix code styles
6d9a18a [lewuathe] [SPARK-5119] Organize test codes
62a150c [lewuathe] [SPARK-5119] Modify Impurities throw exceptions with negatie labels
3336c21 [lewuathe] [SPARK-5119] java.lang.ArrayIndexOutOfBoundsException on trying to train decision tree model

1 files changed, 42 insertions, 0 deletions

diff --git a/mllib/src/test/scala/org/apache/spark/mllib/tree/ImpuritySuite.scala b/mllib/src/test/scala/org/apache/spark/mllib/tree/ImpuritySuite.scala
new file mode 100644
index 0000000000..92b498580a
--- /dev/null
+++ b/mllib/src/test/scala/org/apache/spark/mllib/tree/ImpuritySuite.scala
@@ -0,0 +1,42 @@
+/*
+ * 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.spark.mllib.tree
+
+import org.scalatest.FunSuite
+
+import org.apache.spark.mllib.tree.impurity.{EntropyAggregator, GiniAggregator}
+import org.apache.spark.mllib.util.MLlibTestSparkContext
+
+/**
+ * Test suites for [[GiniAggregator]] and [[EntropyAggregator]].
+ */
+class ImpuritySuite extends FunSuite with MLlibTestSparkContext {
+  test("Gini impurity does not support negative labels") {
+    val gini = new GiniAggregator(2)
+    intercept[IllegalArgumentException] {
+      gini.update(Array(0.0, 1.0, 2.0), 0, -1, 0.0)
+    }
+  }
+
+  test("Entropy does not support negative labels") {
+    val entropy = new EntropyAggregator(2)
+    intercept[IllegalArgumentException] {
+      entropy.update(Array(0.0, 1.0, 2.0), 0, -1, 0.0)
+    }
+  }
+}