Home | History | Annotate | Download | only in base
      1 /*
      2  *  Copyright 2011 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 
     11 #include "webrtc/base/gunit.h"
     12 #include "webrtc/base/rollingaccumulator.h"
     13 
     14 namespace rtc {
     15 
     16 namespace {
     17 
     18 const double kLearningRate = 0.5;
     19 
     20 }  // namespace
     21 
     22 TEST(RollingAccumulatorTest, ZeroSamples) {
     23   RollingAccumulator<int> accum(10);
     24 
     25   EXPECT_EQ(0U, accum.count());
     26   EXPECT_DOUBLE_EQ(0.0, accum.ComputeMean());
     27   EXPECT_DOUBLE_EQ(0.0, accum.ComputeVariance());
     28   EXPECT_EQ(0, accum.ComputeMin());
     29   EXPECT_EQ(0, accum.ComputeMax());
     30 }
     31 
     32 TEST(RollingAccumulatorTest, SomeSamples) {
     33   RollingAccumulator<int> accum(10);
     34   for (int i = 0; i < 4; ++i) {
     35     accum.AddSample(i);
     36   }
     37 
     38   EXPECT_EQ(4U, accum.count());
     39   EXPECT_EQ(6, accum.ComputeSum());
     40   EXPECT_DOUBLE_EQ(1.5, accum.ComputeMean());
     41   EXPECT_NEAR(2.26666, accum.ComputeWeightedMean(kLearningRate), 0.01);
     42   EXPECT_DOUBLE_EQ(1.25, accum.ComputeVariance());
     43   EXPECT_EQ(0, accum.ComputeMin());
     44   EXPECT_EQ(3, accum.ComputeMax());
     45 }
     46 
     47 TEST(RollingAccumulatorTest, RollingSamples) {
     48   RollingAccumulator<int> accum(10);
     49   for (int i = 0; i < 12; ++i) {
     50     accum.AddSample(i);
     51   }
     52 
     53   EXPECT_EQ(10U, accum.count());
     54   EXPECT_EQ(65, accum.ComputeSum());
     55   EXPECT_DOUBLE_EQ(6.5, accum.ComputeMean());
     56   EXPECT_NEAR(10.0, accum.ComputeWeightedMean(kLearningRate), 0.01);
     57   EXPECT_NEAR(9.0, accum.ComputeVariance(), 1.0);
     58   EXPECT_EQ(2, accum.ComputeMin());
     59   EXPECT_EQ(11, accum.ComputeMax());
     60 }
     61 
     62 TEST(RollingAccumulatorTest, ResetSamples) {
     63   RollingAccumulator<int> accum(10);
     64 
     65   for (int i = 0; i < 10; ++i) {
     66     accum.AddSample(100);
     67   }
     68   EXPECT_EQ(10U, accum.count());
     69   EXPECT_DOUBLE_EQ(100.0, accum.ComputeMean());
     70   EXPECT_EQ(100, accum.ComputeMin());
     71   EXPECT_EQ(100, accum.ComputeMax());
     72 
     73   accum.Reset();
     74   EXPECT_EQ(0U, accum.count());
     75 
     76   for (int i = 0; i < 5; ++i) {
     77     accum.AddSample(i);
     78   }
     79 
     80   EXPECT_EQ(5U, accum.count());
     81   EXPECT_EQ(10, accum.ComputeSum());
     82   EXPECT_DOUBLE_EQ(2.0, accum.ComputeMean());
     83   EXPECT_EQ(0, accum.ComputeMin());
     84   EXPECT_EQ(4, accum.ComputeMax());
     85 }
     86 
     87 TEST(RollingAccumulatorTest, RollingSamplesDouble) {
     88   RollingAccumulator<double> accum(10);
     89   for (int i = 0; i < 23; ++i) {
     90     accum.AddSample(5 * i);
     91   }
     92 
     93   EXPECT_EQ(10u, accum.count());
     94   EXPECT_DOUBLE_EQ(875.0, accum.ComputeSum());
     95   EXPECT_DOUBLE_EQ(87.5, accum.ComputeMean());
     96   EXPECT_NEAR(105.049, accum.ComputeWeightedMean(kLearningRate), 0.1);
     97   EXPECT_NEAR(229.166667, accum.ComputeVariance(), 25);
     98   EXPECT_DOUBLE_EQ(65.0, accum.ComputeMin());
     99   EXPECT_DOUBLE_EQ(110.0, accum.ComputeMax());
    100 }
    101 
    102 TEST(RollingAccumulatorTest, ComputeWeightedMeanCornerCases) {
    103   RollingAccumulator<int> accum(10);
    104   EXPECT_DOUBLE_EQ(0.0, accum.ComputeWeightedMean(kLearningRate));
    105   EXPECT_DOUBLE_EQ(0.0, accum.ComputeWeightedMean(0.0));
    106   EXPECT_DOUBLE_EQ(0.0, accum.ComputeWeightedMean(1.1));
    107 
    108   for (int i = 0; i < 8; ++i) {
    109     accum.AddSample(i);
    110   }
    111 
    112   EXPECT_DOUBLE_EQ(3.5, accum.ComputeMean());
    113   EXPECT_DOUBLE_EQ(3.5, accum.ComputeWeightedMean(0));
    114   EXPECT_DOUBLE_EQ(3.5, accum.ComputeWeightedMean(1.1));
    115   EXPECT_NEAR(6.0, accum.ComputeWeightedMean(kLearningRate), 0.1);
    116 }
    117 
    118 }  // namespace rtc
    119