[SPARK-8559] [MLLIB] Support Association Rule Generation

Distributed generation of single-consequent association rules from a RDD of frequent itemsets. Tests referenced against `R`'s implementation of A Priori in [arules](http://cran.r-project.org/web/packages/arules/index.html).

Author: Feynman Liang <fliang@databricks.com>

Closes #7005 from feynmanliang/fp-association-rules-distributed and squashes the following commits:

466ced0 [Feynman Liang] Refactor AR generation impl
73c1cff [Feynman Liang] Make rule attributes public, remove numTransactions from FreqItemset
80f63ff [Feynman Liang] Change default confidence and optimize imports
04cf5b5 [Feynman Liang] Code review with @mengxr, add R to tests
0cc1a6a [Feynman Liang] Java compatibility test
f3c14b5 [Feynman Liang] Fix MiMa test
764375e [Feynman Liang] Fix tests
1187307 [Feynman Liang] Almost working tests
b20779b [Feynman Liang] Working implementation
5395c4e [Feynman Liang] Fix imports
2d34405 [Feynman Liang] Partial implementation of distributed ar
83ace4b [Feynman Liang] Local rule generation without pruning complete
69c2c87 [Feynman Liang] Working local implementation, now to parallelize../..
4e1ec9a [Feynman Liang] Pull FreqItemsets out, refactor type param, tests
69ccedc [Feynman Liang] First implementation of association rule generation

2 files changed, 60 insertions, 3 deletions

diff --git a/mllib/src/test/java/org/apache/spark/mllib/fpm/JavaAssociationRulesSuite.java b/mllib/src/test/java/org/apache/spark/mllib/fpm/JavaAssociationRulesSuite.java
new file mode 100644
index 0000000000..b3815ae603
--- /dev/null
+++ b/mllib/src/test/java/org/apache/spark/mllib/fpm/JavaAssociationRulesSuite.java
@@ -0,0 +1,58 @@
+/*
+ * 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.fpm;
+
+import java.io.Serializable;
+
+import org.junit.After;
+import org.junit.Before;
+import org.junit.Test;
+import com.google.common.collect.Lists;
+
+import org.apache.spark.api.java.JavaRDD;
+import org.apache.spark.api.java.JavaSparkContext;
+import org.apache.spark.mllib.fpm.FPGrowth.FreqItemset;
+
+
+public class JavaAssociationRulesSuite implements Serializable {
+  private transient JavaSparkContext sc;
+
+  @Before
+  public void setUp() {
+    sc = new JavaSparkContext("local", "JavaFPGrowth");
+  }
+
+  @After
+  public void tearDown() {
+    sc.stop();
+    sc = null;
+  }
+
+  @Test
+  public void runAssociationRules() {
+
+    @SuppressWarnings("unchecked")
+    JavaRDD<FPGrowth.FreqItemset<String>> freqItemsets = sc.parallelize(Lists.newArrayList(
+      new FreqItemset<String>(new String[] {"a"}, 15L),
+      new FreqItemset<String>(new String[] {"b"}, 35L),
+      new FreqItemset<String>(new String[] {"a", "b"}, 18L)
+    ));
+
+    JavaRDD<AssociationRules.Rule<String>> results = (new AssociationRules()).run(freqItemsets);
+  }
+}
+
diff --git a/mllib/src/test/java/org/apache/spark/mllib/fpm/JavaFPGrowthSuite.java b/mllib/src/test/java/org/apache/spark/mllib/fpm/JavaFPGrowthSuite.java
index bd0edf2b9e..9ce2c52dca 100644
--- a/mllib/src/test/java/org/apache/spark/mllib/fpm/JavaFPGrowthSuite.java
+++ b/mllib/src/test/java/org/apache/spark/mllib/fpm/JavaFPGrowthSuite.java
@@ -29,7 +29,6 @@ import static org.junit.Assert.*;
 
 import org.apache.spark.api.java.JavaRDD;
 import org.apache.spark.api.java.JavaSparkContext;
-import org.apache.spark.mllib.fpm.FPGrowth.FreqItemset;
 
 public class JavaFPGrowthSuite implements Serializable {
   private transient JavaSparkContext sc;
@@ -62,10 +61,10 @@ public class JavaFPGrowthSuite implements Serializable {
       .setNumPartitions(2)
       .run(rdd);
 
-    List<FreqItemset<String>> freqItemsets = model.freqItemsets().toJavaRDD().collect();
+    List<FPGrowth.FreqItemset<String>> freqItemsets = model.freqItemsets().toJavaRDD().collect();
     assertEquals(18, freqItemsets.size());
 
-    for (FreqItemset<String> itemset: freqItemsets) {
+    for (FPGrowth.FreqItemset<String> itemset: freqItemsets) {
       // Test return types.
       List<String> items = itemset.javaItems();
       long freq = itemset.freq();