1 files changed, 63 insertions, 0 deletions
diff --git a/examples/src/main/scala/Vector.scala b/examples/src/main/scala/Vector.scala
new file mode 100644
index 0000000000..e9fbdca752
--- /dev/null
+++ b/examples/src/main/scala/Vector.scala
@@ -0,0 +1,63 @@
+@serializable class Vector(val elements: Array[Double]) {
+  def length = elements.length
+  
+  def apply(index: Int) = elements(index)
+
+  def + (other: Vector): Vector = {
+    if (length != other.length)
+      throw new IllegalArgumentException("Vectors of different length")
+    return Vector(length, i => this(i) + other(i))
+  }
+
+  def - (other: Vector): Vector = {
+    if (length != other.length)
+      throw new IllegalArgumentException("Vectors of different length")
+    return Vector(length, i => this(i) - other(i))
+  }
+
+  def dot(other: Vector): Double = {
+    if (length != other.length)
+      throw new IllegalArgumentException("Vectors of different length")
+    var ans = 0.0
+    for (i <- 0 until length)
+      ans += this(i) * other(i)
+    return ans
+  }
+
+  def * ( scale: Double): Vector = Vector(length, i => this(i) *  scale)
+
+  def unary_- = this * -1
+  
+  def sum = elements.reduceLeft(_ + _)
+
+  override def toString = elements.mkString("(", ", ", ")")
+
+}
+
+object Vector {
+  def apply(elements: Array[Double]) = new Vector(elements)
+
+  def apply(elements: Double*) = new Vector(elements.toArray)
+
+  def apply(length: Int, initializer: Int => Double): Vector = {
+    val elements = new Array[Double](length)
+    for (i <- 0 until length)
+      elements(i) = initializer(i)
+    return new Vector(elements)
+  }
+
+  def zeros(length: Int) = new Vector(new Array[Double](length))
+
+  def ones(length: Int) = Vector(length, _ => 1)
+
+  class Multiplier(num: Double) {
+    def * (vec: Vector) = vec * num
+  }
+
+  implicit def doubleToMultiplier(num: Double) = new Multiplier(num)
+
+  implicit object VectorAccumParam extends spark.AccumulatorParam[Vector] {
+    def addInPlace(t1: Vector, t2: Vector) = t1 + t2
+    def zero(initialValue: Vector) = Vector.zeros(initialValue.length)
+  }
+}