Cast: Synthetic benchmark tool.

media/cast/test/utility/test_util.cc

+// Copyright 2014 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include <math.h>
+
+#include <algorithm>
+
+#include "base/strings/stringprintf.h"
+#include "media/cast/test/utility/test_util.h"
+
+namespace media {
+namespace cast {
+namespace test {
+
+MeanAndError::MeanAndError(const std::vector<double>& values) {
+  double sum = 0.0;
+  double sqr_sum = 0.0;
+  num_values = values.size();
+  if (num_values) {
+    for (size_t i = 0; i < num_values; i++) {
+      sum += values[i];
+      sqr_sum += values[i] * values[i];
+    }
+    mean = sum / num_values;
+    std_dev =
+        sqrt(std::max(0.0, num_values * sqr_sum - sum * sum)) / num_values;
+  }
+}
+
+std::string MeanAndError::AsString() const {
+  return base::StringPrintf("%f +/- %f", mean, std_dev);
+}
+
+}  // namespace test
+}  // namespace cast
+}  // namespace media