IteratorTest.scala

import scala.io.Source

object IteratorTest {

  def main(args:Array[String]) {

    val s1 = Source.fromFile("/Users/amoghm/src/rand.txt").mkString //returns the file data as String

    //splitting String data with white space and calculating the number of occurrence of each word in the file
    var buf = s1.split("\\s+").map(s => s.trim.toInt)
    println("buffer length " + buf.length)
    val coefficients = Array(34, 45, 56, 78, 90, 32, 12, 13, 45, 56, 89, 67)
    val qlp_shift = 32
    var i = 0
    /**
    * **********************************************
    * Only measuring the performance of below loop.
    * **********************************************
    */
    val t0 = System.nanoTime()
    for (i <- 12 until buf.length) {
      val delta = buf(i);
      val prediction : Int = coefficients
        .zip(buf.slice(i - 12, i))
        .map( {
          case (c, s) => c * s
        }).sum >> qlp_shift
      buf(i) = prediction + delta
    }
    val t1 = System.nanoTime()
    println("Elapsed time: " + (t1 - t0))
  }
}