diff --git a/core/src/main/scala/spark/util/Vector.scala b/core/src/main/scala/spark/util/Vector.scala
index 03559751bc46bea21e8d455323459cc91d73ea9c..835822edb2300969ea40497e9e954f85921ffd5e 100644
--- a/core/src/main/scala/spark/util/Vector.scala
+++ b/core/src/main/scala/spark/util/Vector.scala
@@ -11,12 +11,16 @@ class Vector(val elements: Array[Double]) extends Serializable {
     return Vector(length, i => this(i) + other(i))
   }
 
+  def add(other: Vector) = this + other
+
   def - (other: Vector): Vector = {
     if (length != other.length)
       throw new IllegalArgumentException("Vectors of different length")
     return Vector(length, i => this(i) - other(i))
   }
 
+  def subtract(other: Vector) = this - other
+
   def dot(other: Vector): Double = {
     if (length != other.length)
       throw new IllegalArgumentException("Vectors of different length")
@@ -61,10 +65,16 @@ class Vector(val elements: Array[Double]) extends Serializable {
     this
   }
 
+  def addInPlace(other: Vector) = this +=other
+
   def * (scale: Double): Vector = Vector(length, i => this(i) * scale)
 
+  def multiply (d: Double) = this * d
+
   def / (d: Double): Vector = this * (1 / d)
 
+  def divide (d: Double) = this / d
+
   def unary_- = this * -1
 
   def sum = elements.reduceLeft(_ + _)