1 /*
2 * libjingle
3 * Copyright 2011, Google Inc.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions are met:
7 *
8 * 1. Redistributions of source code must retain the above copyright notice,
9 * this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright notice,
11 * this list of conditions and the following disclaimer in the documentation
12 * and/or other materials provided with the distribution.
13 * 3. The name of the author may not be used to endorse or promote products
14 * derived from this software without specific prior written permission.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
17 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
18 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO
19 * EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
20 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
21 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
22 * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
23 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
24 * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
25 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
26 */
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
TEST(RollingAccumulatorTest,ZeroSamples)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
TEST(RollingAccumulatorTest,SomeSamples)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
TEST(RollingAccumulatorTest,RollingSamples)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
TEST(RollingAccumulatorTest,RollingSamplesDouble)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
TEST(RollingAccumulatorTest,ComputeWeightedMeanCornerCases)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
103