Data commit

Task/Monte-Carlo-methods/Scala/monte-carlo-methods.scala

@@ -0,0 +1,27 @@
+object MonteCarlo {
+  private val random = new scala.util.Random
+
+  /** Returns a random number between -1 and 1 */
+  def nextThrow: Double = (random.nextDouble * 2.0) - 1.0
+
+  /** Returns true if the argument point would be 'inside' the unit circle with
+    * center at the origin, and bounded by a square with side lengths of 2
+    * units. */
+  def insideCircle(pt: (Double, Double)): Boolean = pt match {
+    case (x, y) => (x * x) + (y * y) <= 1.0
+  }
+
+  /** Runs the simulation the specified number of times. Uses the result to
+    * estimate a value of pi */
+  def simulate(times: Int): Double = {
+    val inside = Iterator.tabulate (times) (_ => (nextThrow, nextThrow)) count insideCircle
+    inside.toDouble / times.toDouble * 4.0
+  }
+
+  def main(args: Array[String]): Unit = {
+    val sims = Seq(10000, 100000, 1000000, 10000000, 100000000)
+    sims.foreach { n =>
+      println(n+" simulations; pi estimation: "+ simulate(n))
+    }
+  }
+}