[SPARK-6308] [MLlib] [Sql] Override TypeName in VectorUDT and MatrixUDT

Author: MechCoder <manojkumarsivaraj334@gmail.com>

Closes #5118 from MechCoder/spark-6308 and squashes the following commits:

6c8ffab [MechCoder] Add test for simpleString
b966242 [MechCoder] [SPARK-6308] [MLlib][Sql] VectorUDT is displayed as vecto in dtypes

mllib/src/main/scala/org/apache/spark/mllib/linalg/Matrices.scala

@@ -187,6 +187,8 @@ private[spark] class MatrixUDT extends UserDefinedType[Matrix] {
 
   override def hashCode(): Int = 1994
 
+  override def typeName: String = "matrix"
+
   private[spark] override def asNullable: MatrixUDT = this
 }
 

mllib/src/main/scala/org/apache/spark/mllib/linalg/Vectors.scala

@@ -185,6 +185,8 @@ private[spark] class VectorUDT extends UserDefinedType[Vector] {
 
   override def hashCode: Int = 7919
 
+  override def typeName: String = "vector"
+
   private[spark] override def asNullable: VectorUDT = this
 }
 

mllib/src/test/scala/org/apache/spark/mllib/linalg/MatricesSuite.scala

@@ -436,5 +436,7 @@ class MatricesSuite extends FunSuite {
     Seq(dm1, dm2, dm3, sm1, sm2, sm3).foreach {
         mat => assert(mat.toArray === mUDT.deserialize(mUDT.serialize(mat)).toArray)
     }
+    assert(mUDT.typeName == "matrix")
+    assert(mUDT.simpleString == "matrix")
   }
 }

mllib/src/test/scala/org/apache/spark/mllib/linalg/VectorsSuite.scala

@@ -187,6 +187,8 @@ class VectorsSuite extends FunSuite {
     for (v <- Seq(dv0, dv1, sv0, sv1)) {
       assert(v === udt.deserialize(udt.serialize(v)))
     }
+    assert(udt.typeName == "vector")
+    assert(udt.simpleString == "vector")
   }
 
   test("fromBreeze") {