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* Copyright 2011, Google Inc.
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions are met:
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* 1. Redistributions of source code must retain the above copyright notice,
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* this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright notice,
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* this list of conditions and the following disclaimer in the documentation
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* and/or other materials provided with the distribution.
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* 3. The name of the author may not be used to endorse or promote products
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* derived from this software without specific prior written permission.
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* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
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* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
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* MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO
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* EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
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* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
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* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
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* OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
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* WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
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* OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
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* ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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#include "talk/base/gunit.h"
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#include "talk/base/rollingaccumulator.h"
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static bool IsApproximate(double expected, double value, double eps) {
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return expected - eps <= value && value <= expected + eps;
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TEST(RollingAccumulatorTest, TestZeroSamples) {
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RollingAccumulator<int> accum(10);
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EXPECT_EQ(0U, accum.count());
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EXPECT_EQ(0, accum.ComputeMean());
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EXPECT_EQ(0, accum.ComputeVariance());
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TEST(RollingAccumulatorTest, TestSomeSamples) {
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RollingAccumulator<int> accum(10);
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for (int i = 0; i < 4; ++i) {
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EXPECT_EQ(4U, accum.count());
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EXPECT_EQ(6, accum.ComputeSum());
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EXPECT_EQ(1, accum.ComputeMean());
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EXPECT_EQ(1, accum.ComputeVariance());
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TEST(RollingAccumulatorTest, TestRollingSamples) {
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RollingAccumulator<int> accum(10);
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for (int i = 0; i < 12; ++i) {
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EXPECT_EQ(10U, accum.count());
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EXPECT_EQ(65, accum.ComputeSum());
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EXPECT_EQ(6, accum.ComputeMean());
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EXPECT_TRUE(IsApproximate(9, accum.ComputeVariance(), 1));
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TEST(RollingAccumulatorTest, TestRollingSamplesDouble) {
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RollingAccumulator<double> accum(10);
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for (int i = 0; i < 23; ++i) {
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accum.AddSample(5 * i);
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EXPECT_EQ(10U, accum.count());
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EXPECT_TRUE(IsApproximate(875.0, accum.ComputeSum(), 1E-6));
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EXPECT_TRUE(IsApproximate(87.5, accum.ComputeMean(), 1E-6));
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EXPECT_TRUE(IsApproximate(229.166667, accum.ComputeVariance(), 25));
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} // namespace talk_base