Scala example source code file (MatrixMultiplication.scala)

This example Scala source code file (MatrixMultiplication.scala) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" ^TM.

Java - Scala tags/keywords

array, int, int, manifest, matrix, matrix, matrixmultiplication, matrixmultiplication, numeric, parrange, string, string, t, unsupportedoperationexception

The Scala MatrixMultiplication.scala source code

package scala.collection.parallel.benchmarks.parallel_array



import collection.parallel.immutable.ParRange


object MatrixMultiplication extends Companion {
  def benchName = "matrix-mult";
  def apply(sz: Int, parallelism: Int, what: String) = new MatrixMultiplication(sz, parallelism, what)
  override def comparisons = List()
  override def defaultSize = 100
}

class MatrixMultiplication(sz: Int, p: Int, what: String)
extends Resettable(sz, p, what, new Cont(_), new Array[Any](_), classOf[Cont]) {
  def companion = MatrixMultiplication
  collection.parallel.tasksupport.environment = forkjoinpool
  
  val a = Matrix.unit[Int](sz)
  val b = Matrix.unit[Int](sz)
  var c = new Matrix[Int](sz)
  
  def runpar = c = a * b //{ c.assignProduct(a, b) } //; println("--------"); c.output }
  def runseq = throw new UnsupportedOperationException
  def comparisonMap = collection.Map()
  
  class Matrix[T](n: Int)(implicit num: Numeric[T], man: Manifest[T]) {
    val array = new Array[T](n * n)
    
    def apply(y: Int, x: Int) = array(y * n + x)
    
    def update(y: Int, x: Int, elem: T) = array(y * n + x) = elem
    
    def *(b: Matrix[T]) = {
      val m = new Matrix[T](n)
      m.assignProduct(this, b)
      m
    }
    
    def assignProduct(a: Matrix[T], b: Matrix[T]) = {
      val range = ParRange(0, n * n, 1, false)
      for (i <- range) this(i / n, i % n) = calcProduct(a, b, i / n, i % n);
    }
    
    private def calcProduct(a: Matrix[T], b: Matrix[T], y: Int, x: Int): T = {
      import num._
      var sum = zero
      for (i <- 0 until n) sum += a(y, i) * b(i, x)
      sum
    }
    
    def output = for (y <- 0 until n) {
      for (x <- 0 until n) print(this(y, x))
      println
    }
  }
  
  object Matrix {
    def unit[T](n: Int)(implicit num: Numeric[T], man: Manifest[T]) = {
      val m = new Matrix[T](n)
      for (i <- 0 until n) m(i, i) = num.one
      m
    }
  }
  
}