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Unified Diff: tests/lib/math/low_test.dart

Issue 10389150: - Add a math library. Currently it mostly matches the Math class in dart:core. (Closed) Base URL: http://dart.googlecode.com/svn/branches/bleeding_edge/dart/
Patch Set: Created 8 years, 7 months ago
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Index: tests/lib/math/low_test.dart
===================================================================
--- tests/lib/math/low_test.dart (revision 0)
+++ tests/lib/math/low_test.dart (revision 0)
@@ -0,0 +1,31 @@
+// 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 uniformly distribute values when not using
+// a power of 2.
+
+// Library tag to allow Dartium to run the test.
+#library("low_test.dart");
+
+#import("dart:math");
+
+void main() {
+ var n = (2 * (1<<32)) ~/ 3;
+ var n2 = n ~/ 2;
+
+ var iterations = 200000;
+
+ var prng = new Random();
+
+ var low = 0;
+ for (var i = 0; i < iterations; i++) {
+ if (prng.nextInt(n) < n2) {
+ low++;
+ }
+ }
+
+ var diff = (low - (iterations ~/ 2)).abs();
+ print("$low, $diff");
kasperl 2012/05/23 12:40:46 Debug printing?
+ Expect.isTrue(diff < (iterations ~/ 20));
+}

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