diff --git a/src/lib/mathlib/CMakeLists.txt b/src/lib/mathlib/CMakeLists.txt index 2e9e8d2eb0..d5e7d9e046 100644 --- a/src/lib/mathlib/CMakeLists.txt +++ b/src/lib/mathlib/CMakeLists.txt @@ -43,3 +43,4 @@ px4_add_unit_gtest(SRC math/test/AlphaFilterTest.cpp) px4_add_unit_gtest(SRC math/test/MedianFilterTest.cpp) px4_add_unit_gtest(SRC math/test/NotchFilterTest.cpp) px4_add_unit_gtest(SRC math/FunctionsTest.cpp) +px4_add_unit_gtest(SRC math/WelfordMeanTest.cpp) diff --git a/src/lib/mathlib/math/WelfordMeanTest.cpp b/src/lib/mathlib/math/WelfordMeanTest.cpp new file mode 100644 index 0000000000..06b59e6dfb --- /dev/null +++ b/src/lib/mathlib/math/WelfordMeanTest.cpp @@ -0,0 +1,66 @@ +/**************************************************************************** + * + * Copyright (C) 2021 PX4 Development Team. All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in + * the documentation and/or other materials provided with the + * distribution. + * 3. Neither the name PX4 nor the names of its contributors may be + * used to endorse or promote products derived from this software + * without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS + * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT + * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS + * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE + * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, + * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, + * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS + * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED + * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT + * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN + * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE + * POSSIBILITY OF SUCH DAMAGE. + * + ****************************************************************************/ + +#include +#include +#include +#include "WelfordMean.hpp" + +using namespace math; +using matrix::Vector3f; + +TEST(WelfordMeanTest, NoisySignal) +{ + const float std_dev = 3.f; + std::normal_distribution standard_normal_distribution{0.f, std_dev}; + std::default_random_engine random_generator{}; // Pseudo-random generator with constant seed + random_generator.seed(42); + WelfordMean welford{}; + + for (int i = 0; i < 50; i++) { + const float noisy_value = standard_normal_distribution(random_generator); + welford.update(Vector3f(noisy_value, noisy_value - 1.f, noisy_value + 1.f)); + } + + EXPECT_TRUE(welford.valid()); + const Vector3f mean = welford.mean(); + const Vector3f var = welford.variance(); + const float var_real = std_dev * std_dev; + + EXPECT_NEAR(mean(0), 0.f, 0.7f); + EXPECT_NEAR(mean(1), -1.f, 0.7f); + EXPECT_NEAR(mean(2), 1.f, 0.7f); + EXPECT_NEAR(var(0), var_real, 0.1f); + EXPECT_NEAR(var(1), var_real, 0.1f); + EXPECT_NEAR(var(2), var_real, 0.1f); +}