1f8ee788a64d60abd8f2d742a5fdedde054ecd910Torne (Richard Coles)// Copyright 2014 The Chromium Authors. All rights reserved. 2f8ee788a64d60abd8f2d742a5fdedde054ecd910Torne (Richard Coles)// Use of this source code is governed by a BSD-style license that can be 3f8ee788a64d60abd8f2d742a5fdedde054ecd910Torne (Richard Coles)// found in the LICENSE file. 4f8ee788a64d60abd8f2d742a5fdedde054ecd910Torne (Richard Coles) 5f8ee788a64d60abd8f2d742a5fdedde054ecd910Torne (Richard Coles)#include <math.h> 6f8ee788a64d60abd8f2d742a5fdedde054ecd910Torne (Richard Coles) 7f8ee788a64d60abd8f2d742a5fdedde054ecd910Torne (Richard Coles)#include <algorithm> 8f8ee788a64d60abd8f2d742a5fdedde054ecd910Torne (Richard Coles) 9f8ee788a64d60abd8f2d742a5fdedde054ecd910Torne (Richard Coles)#include "base/strings/stringprintf.h" 10f8ee788a64d60abd8f2d742a5fdedde054ecd910Torne (Richard Coles)#include "media/cast/test/utility/test_util.h" 11f8ee788a64d60abd8f2d742a5fdedde054ecd910Torne (Richard Coles) 12f8ee788a64d60abd8f2d742a5fdedde054ecd910Torne (Richard Coles)namespace media { 13f8ee788a64d60abd8f2d742a5fdedde054ecd910Torne (Richard Coles)namespace cast { 14f8ee788a64d60abd8f2d742a5fdedde054ecd910Torne (Richard Coles)namespace test { 15f8ee788a64d60abd8f2d742a5fdedde054ecd910Torne (Richard Coles) 16f8ee788a64d60abd8f2d742a5fdedde054ecd910Torne (Richard Coles)MeanAndError::MeanAndError(const std::vector<double>& values) { 17f8ee788a64d60abd8f2d742a5fdedde054ecd910Torne (Richard Coles) double sum = 0.0; 18f8ee788a64d60abd8f2d742a5fdedde054ecd910Torne (Richard Coles) double sqr_sum = 0.0; 19f8ee788a64d60abd8f2d742a5fdedde054ecd910Torne (Richard Coles) num_values = values.size(); 20f8ee788a64d60abd8f2d742a5fdedde054ecd910Torne (Richard Coles) if (num_values) { 21f8ee788a64d60abd8f2d742a5fdedde054ecd910Torne (Richard Coles) for (size_t i = 0; i < num_values; i++) { 22f8ee788a64d60abd8f2d742a5fdedde054ecd910Torne (Richard Coles) sum += values[i]; 23f8ee788a64d60abd8f2d742a5fdedde054ecd910Torne (Richard Coles) sqr_sum += values[i] * values[i]; 24f8ee788a64d60abd8f2d742a5fdedde054ecd910Torne (Richard Coles) } 25f8ee788a64d60abd8f2d742a5fdedde054ecd910Torne (Richard Coles) mean = sum / num_values; 26f8ee788a64d60abd8f2d742a5fdedde054ecd910Torne (Richard Coles) std_dev = 27f8ee788a64d60abd8f2d742a5fdedde054ecd910Torne (Richard Coles) sqrt(std::max(0.0, num_values * sqr_sum - sum * sum)) / num_values; 28f8ee788a64d60abd8f2d742a5fdedde054ecd910Torne (Richard Coles) } 29f8ee788a64d60abd8f2d742a5fdedde054ecd910Torne (Richard Coles)} 30f8ee788a64d60abd8f2d742a5fdedde054ecd910Torne (Richard Coles) 31f8ee788a64d60abd8f2d742a5fdedde054ecd910Torne (Richard Coles)std::string MeanAndError::AsString() const { 32f8ee788a64d60abd8f2d742a5fdedde054ecd910Torne (Richard Coles) return base::StringPrintf("%f +/- %f", mean, std_dev); 33f8ee788a64d60abd8f2d742a5fdedde054ecd910Torne (Richard Coles)} 34f8ee788a64d60abd8f2d742a5fdedde054ecd910Torne (Richard Coles) 35f8ee788a64d60abd8f2d742a5fdedde054ecd910Torne (Richard Coles)} // namespace test 36f8ee788a64d60abd8f2d742a5fdedde054ecd910Torne (Richard Coles)} // namespace cast 37f8ee788a64d60abd8f2d742a5fdedde054ecd910Torne (Richard Coles)} // namespace media 38