add some functionality to Vector, delete copy in AccumulatorSuite

core/src/main/scala/spark/util/Vector.scala

@@ -29,7 +29,37 @@ class Vector(val elements: Array[Double]) extends Serializable {
     return ans
   }
 
-  def * (scale: Double): Vector = Vector(length, i => this(i) * scale)
+  /**
+   * return (this + plus) dot other, but without creating any intermediate storage
+   * @param plus
+   * @param other
+   * @return
+   */
+  def plusDot(plus: Vector, other: Vector): Double = {
+    if (length != other.length)
+      throw new IllegalArgumentException("Vectors of different length")
+    if (length != plus.length)
+      throw new IllegalArgumentException("Vectors of different length")
+    var ans = 0.0
+    var i = 0
+    while (i < length) {
+      ans += (this(i) + plus(i)) * other(i)
+      i += 1
+    }
+    return ans
+  }
+
+  def +=(other: Vector) {
+    if (length != other.length)
+      throw new IllegalArgumentException("Vectors of different length")
+    var ans = 0.0
+    var i = 0
+    while (i < length) {
+      elements(i) += other(i)
+      i += 1
+    }
+  }
+
   def * (scale: Double): Vector = Vector(length, i => this(i) * scale)
 
   def / (d: Double): Vector = this * (1 / d)

core/src/test/scala/spark/AccumulatorSuite.scala

@@ -64,8 +64,7 @@ class AccumulatorSuite extends FunSuite with ShouldMatchers {
 
 
   test ("value readable in tasks") {
-    import Vector.VectorAccumParam._
-    import Vector._
+    import spark.util.Vector
     //stochastic gradient descent with weights stored in accumulator -- should be able to read value as we go
 
     //really easy data
@@ -121,113 +120,4 @@ class AccumulatorSuite extends FunSuite with ShouldMatchers {
     }
   }
 
-}
-
+}
\ No newline at end of file
-
-
-//ugly copy and paste from examples ...
-class Vector(val elements: Array[Double]) extends Serializable {
-  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
-    var i = 0
-    while (i < length) {
-      ans += this(i) * other(i)
-      i += 1
-    }
-    return ans
-  }
-
-  def plusDot(plus: Vector, other: Vector): Double = {
-    if (length != other.length)
-      throw new IllegalArgumentException("Vectors of different length")
-    if (length != plus.length)
-      throw new IllegalArgumentException("Vectors of different length")
-    var ans = 0.0
-    var i = 0
-    while (i < length) {
-      ans += (this(i) + plus(i)) * other(i)
-      i += 1
-    }
-    return ans
-  }
-
-  def += (other: Vector) {
-    if (length != other.length)
-      throw new IllegalArgumentException("Vectors of different length")
-    var ans = 0.0
-    var i = 0
-    while (i < length) {
-      elements(i) += other(i)
-      i += 1
-    }
-  }
-
-
-  def * (scale: Double): Vector = Vector(length, i => this(i) * scale)
-
-  def / (d: Double): Vector = this * (1 / d)
-
-  def unary_- = this * -1
-
-  def sum = elements.reduceLeft(_ + _)
-
-  def squaredDist(other: Vector): Double = {
-    var ans = 0.0
-    var i = 0
-    while (i < length) {
-      ans += (this(i) - other(i)) * (this(i) - other(i))
-      i += 1
-    }
-    return ans
-  }
-
-  def dist(other: Vector): Double = math.sqrt(squaredDist(other))
-
-  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)
-  }
-}