src/third_party/libjingle/source/talk/base/rollingaccumulator_unittest.cc

   1 /*
   2  * libjingle
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  12  *     and/or other materials provided with the distribution.
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  14  *     derived from this software without specific prior written permission.
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  17  * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
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  19  * EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
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  27
  28 #include "talk/base/gunit.h"
  29 #include "talk/base/rollingaccumulator.h"
  30
  31 namespace talk_base {
  32
  33 namespace {
  34
  35 const double kLearningRate = 0.5;
  36
  37 }  // namespace
  38
  39 TEST(RollingAccumulatorTest, ZeroSamples) {
  40   RollingAccumulator<int> accum(10);
  41
  42   EXPECT_EQ(0U, accum.count());
  43   EXPECT_EQ(0, accum.ComputeMean());
  44   EXPECT_EQ(0, accum.ComputeVariance());
  45 }
  46
  47 TEST(RollingAccumulatorTest, SomeSamples) {
  48   RollingAccumulator<int> accum(10);
  49   for (int i = 0; i < 4; ++i) {
  50     accum.AddSample(i);
  51   }
  52
  53   EXPECT_EQ(4U, accum.count());
  54   EXPECT_EQ(6, accum.ComputeSum());
  55   EXPECT_EQ(1, accum.ComputeMean());
  56   EXPECT_EQ(2, accum.ComputeWeightedMean(kLearningRate));
  57   EXPECT_EQ(1, accum.ComputeVariance());
  58 }
  59
  60 TEST(RollingAccumulatorTest, RollingSamples) {
  61   RollingAccumulator<int> accum(10);
  62   for (int i = 0; i < 12; ++i) {
  63     accum.AddSample(i);
  64   }
  65
  66   EXPECT_EQ(10U, accum.count());
  67   EXPECT_EQ(65, accum.ComputeSum());
  68   EXPECT_EQ(6, accum.ComputeMean());
  69   EXPECT_EQ(10, accum.ComputeWeightedMean(kLearningRate));
  70   EXPECT_NEAR(9, accum.ComputeVariance(), 1);
  71 }
  72
  73 TEST(RollingAccumulatorTest, RollingSamplesDouble) {
  74   RollingAccumulator<double> accum(10);
  75   for (int i = 0; i < 23; ++i) {
  76     accum.AddSample(5 * i);
  77   }
  78
  79   EXPECT_EQ(10u, accum.count());
  80   EXPECT_DOUBLE_EQ(875.0, accum.ComputeSum());
  81   EXPECT_DOUBLE_EQ(87.5, accum.ComputeMean());
  82   EXPECT_NEAR(105.049, accum.ComputeWeightedMean(kLearningRate), 0.1);
  83   EXPECT_NEAR(229.166667, accum.ComputeVariance(), 25);
  84 }
  85
  86 TEST(RollingAccumulatorTest, ComputeWeightedMeanCornerCases) {
  87   RollingAccumulator<int> accum(10);
  88   EXPECT_EQ(0, accum.ComputeWeightedMean(kLearningRate));
  89   EXPECT_EQ(0, accum.ComputeWeightedMean(0.0));
  90   EXPECT_EQ(0, accum.ComputeWeightedMean(1.1));
  91
  92   for (int i = 0; i < 8; ++i) {
  93     accum.AddSample(i);
  94   }
  95
  96   EXPECT_EQ(3, accum.ComputeMean());
  97   EXPECT_EQ(3, accum.ComputeWeightedMean(0));
  98   EXPECT_EQ(3, accum.ComputeWeightedMean(1.1));
  99   EXPECT_EQ(6, accum.ComputeWeightedMean(kLearningRate));
 100 }
 101
 102 }  // namespace talk_base