add VectorRDDs with a converter from RDD[Array[Double]]

mllib/src/main/scala/org/apache/spark/mllib/linalg/rdd/VectorRDDs.scala

@@ -0,0 +1,32 @@
+/*
+ * 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.linalg.rdd
+
+import org.apache.spark.rdd.RDD
+import org.apache.spark.mllib.linalg.{Vectors, Vector}
+
+/**
+ * Factory methods for `RDD[Vector]`.
+ */
+object VectorRDDs {
+
+  /**
+   * Converts an `RDD[Array[Double]]` to `RDD[Vector]`.
+   */
+  def fromArrayRDD(rdd: RDD[Array[Double]]): RDD[Vector] = rdd.map(v => Vectors.dense(v))
+}

mllib/src/test/scala/org/apache/spark/mllib/linalg/rdd/VectorRDDsSuite.scala

@@ -0,0 +1,33 @@
+/*
+ * 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.linalg.rdd
+
+import org.scalatest.FunSuite
+
+import org.apache.spark.mllib.linalg.Vectors
+import org.apache.spark.mllib.util.LocalSparkContext
+
+class VectorRDDsSuite extends FunSuite with LocalSparkContext {
+
+  test("from array rdd") {
+    val data = Seq(Array(1.0, 2.0), Array(3.0, 4.0))
+    val arrayRdd = sc.parallelize(data, 2)
+    val vectorRdd = VectorRDDs.fromArrayRDD(arrayRdd)
+    assert(arrayRdd.collect().map(v => Vectors.dense(v)).view === vectorRdd.collect().view)
+  }
+}