Migrated test block 216 to Dart 2.0.

tests/lib/math/pi_test.dart

-// Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
-// for details. All rights reserved. Use of this source code is governed by a
-// BSD-style license that can be found in the LICENSE file.
-
-// Test that the default PRNG does converge towards Pi when doing a Monte Carlo
-// simulation.
-
-// Library tag to allow Dartium to run the test.
-library pi_test;
-
-import "package:expect/expect.dart";
-import 'dart:math';
-
-var known_bad_seeds = const [50051, 55597, 59208];
-
-void main([args]) {
-  // Select a seed either from the argument passed in or
-  // otherwise a random seed.
-  var seed = -1;
-  if ((args != null) && (args.length > 0)) {
-    seed = int.parse(args[0]);
-  } else {
-    var seed_prng = new Random();
-    while (seed == -1) {
-      seed = seed_prng.nextInt(1 << 16);
-      if (known_bad_seeds.contains(seed)) {
-        // Reset seed and try again.
-        seed = -1;
-      }
-    }
-  }
-
-  // Setup the PRNG for the Monte Carlo simulation.
-  print("pi_test seed: $seed");
-  var prng = new Random(seed);
-
-  var outside = 0;
-  var inside = 0;
-  for (var i = 0; i < 600000; i++) {
-    var x = prng.nextDouble();
-    var y = prng.nextDouble();
-    if ((x * x) + (y * y) < 1.0) {
-      inside++;
-    } else {
-      outside++;
-    }
-  }
-  // Mmmmh, Pie!
-  var pie = 4.0 * (inside / (inside + outside));
-  print("$pie");
-  Expect.isTrue(((PI - 0.009) < pie) && (pie < (PI + 0.009)));
-}