1 /* 2 * Copyright (c) 2013 The WebRTC project authors. All Rights Reserved. 3 * 4 * Use of this source code is governed by a BSD-style license 5 * that can be found in the LICENSE file in the root of the source 6 * tree. An additional intellectual property rights grant can be found 7 * in the file PATENTS. All contributing project authors may 8 * be found in the AUTHORS file in the root of the source tree. 9 */ 10 #include "webrtc/test/statistics.h" 11 12 #include <math.h> 13 14 namespace webrtc { 15 namespace test { 16 17 Statistics::Statistics() : sum_(0.0), sum_squared_(0.0), count_(0) {} 18 19 void Statistics::AddSample(double sample) { 20 sum_ += sample; 21 sum_squared_ += sample * sample; 22 ++count_; 23 } 24 25 double Statistics::Mean() const { 26 if (count_ == 0) 27 return 0.0; 28 return sum_ / count_; 29 } 30 31 double Statistics::Variance() const { 32 if (count_ == 0) 33 return 0.0; 34 return sum_squared_ / count_ - Mean() * Mean(); 35 } 36 37 double Statistics::StandardDeviation() const { 38 return sqrt(Variance()); 39 } 40 } // namespace test 41 } // namespace webrtc 42
