[SPARK-9661] [MLLIB] [ML] Java compatibility

I skimmed through the docs for various instance of Object and replaced them with Java compaible versions of the same.

1. Some methods in LDAModel.
2. runMiniBatchSGD
3. kolmogorovSmirnovTest

Author: MechCoder <manojkumarsivaraj334@gmail.com>

Closes #8126 from MechCoder/java_incop.

2 files changed, 40 insertions, 3 deletions

diff --git a/mllib/src/main/scala/org/apache/spark/mllib/clustering/LDAModel.scala b/mllib/src/main/scala/org/apache/spark/mllib/clustering/LDAModel.scala
index 5dc637ebdc..f31949f13a 100644
--- a/mllib/src/main/scala/org/apache/spark/mllib/clustering/LDAModel.scala
+++ b/mllib/src/main/scala/org/apache/spark/mllib/clustering/LDAModel.scala
@@ -26,7 +26,7 @@ import org.json4s.jackson.JsonMethods._
 
 import org.apache.spark.SparkContext
 import org.apache.spark.annotation.Experimental
-import org.apache.spark.api.java.JavaPairRDD
+import org.apache.spark.api.java.{JavaPairRDD, JavaRDD}
 import org.apache.spark.graphx.{Edge, EdgeContext, Graph, VertexId}
 import org.apache.spark.mllib.linalg.{Matrices, Matrix, Vector, Vectors}
 import org.apache.spark.mllib.util.{Loader, Saveable}
@@ -228,6 +228,11 @@ class LocalLDAModel private[clustering] (
     docConcentration, topicConcentration, topicsMatrix.toBreeze.toDenseMatrix, gammaShape, k,
     vocabSize)
 
+  /** Java-friendly version of [[logLikelihood]] */
+  def logLikelihood(documents: JavaPairRDD[java.lang.Long, Vector]): Double = {
+    logLikelihood(documents.rdd.asInstanceOf[RDD[(Long, Vector)]])
+  }
+
   /**
    * Calculate an upper bound bound on perplexity.  (Lower is better.)
    * See Equation (16) in original Online LDA paper.
@@ -242,6 +247,11 @@ class LocalLDAModel private[clustering] (
     -logLikelihood(documents) / corpusTokenCount
   }
 
+  /** Java-friendly version of [[logPerplexity]] */
+  def logPerplexity(documents: JavaPairRDD[java.lang.Long, Vector]): Double = {
+    logPerplexity(documents.rdd.asInstanceOf[RDD[(Long, Vector)]])
+  }
+
   /**
    * Estimate the variational likelihood bound of from `documents`:
    *    log p(documents) >= E_q[log p(documents)] - E_q[log q(documents)]
@@ -341,8 +351,14 @@ class LocalLDAModel private[clustering] (
     }
   }
 
-}
+  /** Java-friendly version of [[topicDistributions]] */
+  def topicDistributions(
+      documents: JavaPairRDD[java.lang.Long, Vector]): JavaPairRDD[java.lang.Long, Vector] = {
+    val distributions = topicDistributions(documents.rdd.asInstanceOf[RDD[(Long, Vector)]])
+    JavaPairRDD.fromRDD(distributions.asInstanceOf[RDD[(java.lang.Long, Vector)]])
+  }
 
+}
 
 @Experimental
 object LocalLDAModel extends Loader[LocalLDAModel] {
@@ -657,6 +673,13 @@ class DistributedLDAModel private[clustering] (
     }
   }
 
+  /** Java-friendly version of [[topTopicsPerDocument]] */
+  def javaTopTopicsPerDocument(
+      k: Int): JavaRDD[(java.lang.Long, Array[Int], Array[java.lang.Double])] = {
+    val topics = topTopicsPerDocument(k)
+    topics.asInstanceOf[RDD[(java.lang.Long, Array[Int], Array[java.lang.Double])]].toJavaRDD()
+  }
+
   // TODO:
   // override def topicDistributions(documents: RDD[(Long, Vector)]): RDD[(Long, Vector)] = ???
 
diff --git a/mllib/src/main/scala/org/apache/spark/mllib/stat/Statistics.scala b/mllib/src/main/scala/org/apache/spark/mllib/stat/Statistics.scala
index f84502919e..24fe48cb8f 100644
--- a/mllib/src/main/scala/org/apache/spark/mllib/stat/Statistics.scala
+++ b/mllib/src/main/scala/org/apache/spark/mllib/stat/Statistics.scala
@@ -20,7 +20,7 @@ package org.apache.spark.mllib.stat
 import scala.annotation.varargs
 
 import org.apache.spark.annotation.Experimental
-import org.apache.spark.api.java.JavaRDD
+import org.apache.spark.api.java.{JavaRDD, JavaDoubleRDD}
 import org.apache.spark.mllib.linalg.distributed.RowMatrix
 import org.apache.spark.mllib.linalg.{Matrix, Vector}
 import org.apache.spark.mllib.regression.LabeledPoint
@@ -178,6 +178,9 @@ object Statistics {
     ChiSqTest.chiSquaredFeatures(data)
   }
 
+  /** Java-friendly version of [[chiSqTest()]] */
+  def chiSqTest(data: JavaRDD[LabeledPoint]): Array[ChiSqTestResult] = chiSqTest(data.rdd)
+
   /**
    * Conduct the two-sided Kolmogorov-Smirnov (KS) test for data sampled from a
    * continuous distribution. By comparing the largest difference between the empirical cumulative
@@ -212,4 +215,15 @@ object Statistics {
     : KolmogorovSmirnovTestResult = {
     KolmogorovSmirnovTest.testOneSample(data, distName, params: _*)
   }
+
+  /** Java-friendly version of [[kolmogorovSmirnovTest()]] */
+  @varargs
+  def kolmogorovSmirnovTest(
+      data: JavaDoubleRDD,
+      distName: String,
+      params: java.lang.Double*): KolmogorovSmirnovTestResult = {
+    val javaParams = params.asInstanceOf[Seq[Double]]
+    KolmogorovSmirnovTest.testOneSample(data.rdd.asInstanceOf[RDD[Double]],
+      distName, javaParams: _*)
+  }
 }