DailyProgrammer[7/13/2012]

Hist.scala

//print a histogram

import scala.util.Random
import scala.annotation.tailrec

def twoDice(): Int = {
  val r1 = Random
  (r1.nextInt(6)+1) + (r1.nextInt(6) +1)
}

def graph(f: => Int, low: Int, high: Int, tests: Int) = {

  @tailrec
  def go(l: List[Int], n: Int): List[Int] =
    if( n >= tests) l else go(f :: l, n +1)

  def scale(n: Int): Int = (n.toDouble / tests.toDouble * 100.0).toInt

  val samples = go(Nil,0)

  samples.groupBy(identity)
    .mapValues(_.size)
    .toList
    .sortBy(_._1)
    .foreach {
    case (k, v) =>
      val hist = "#" * scale(v)
      println(s"$k $hist \n")
  }

}

//graph(twoDice, 0,0,1000)