cpu/utils/quadratic_equation.cpp

0001 // This file is part of the ACTS project.
0002 //
0003 // Copyright (C) 2016 CERN for the benefit of the ACTS project
0004 //
0005 // This Source Code Form is subject to the terms of the Mozilla Public
0006 // License, v. 2.0. If a copy of the MPL was not distributed with this
0007 // file, You can obtain one at https://mozilla.org/MPL/2.0/.
0008
0009 // detray core
0010 #include "detray/utils/quadratic_equation.hpp"
0011
0012 #include "detray/definitions/algebra.hpp"
0013 #include "detray/utils/tuple_helpers.hpp"
0014
0015 // Detray test include(s)
0016 #include "detray/test/framework/types.hpp"
0017
0018 // GTest include(s)
0019 #include <gtest/gtest.h>
0020
0021 using namespace detray;
0022
0023 using scalar = test::scalar;
0024
0025 // This tests the convenience quadratic equation class
0026 GTEST_TEST(detray_utils, quadratic_equation) {
0027   static constexpr scalar epsilon{1e-5f};
0028
0029   // No solution
0030   detail::quadratic_equation<scalar> qe1{1.5f, 0.f, 1.f};
0031
0032   ASSERT_EQ(qe1.solutions(), 0);
0033
0034   // One solution
0035   detail::quadratic_equation<scalar> qe2{1.f, 0.f, 0.f};
0036
0037   ASSERT_EQ(qe2.solutions(), 1);
0038   EXPECT_NEAR(qe2.smaller(), 0.f, epsilon);
0039
0040   detail::quadratic_equation<scalar> qe3{0.f, 1.f, 2.f};
0041
0042   ASSERT_EQ(qe3.solutions(), 1);
0043   EXPECT_NEAR(qe3.smaller(), -2.f, epsilon);
0044
0045   // Two solutions
0046   detail::quadratic_equation<scalar> qe4{2.f, 5.f, 3.f};
0047
0048   ASSERT_EQ(qe4.solutions(), 2);
0049   EXPECT_NEAR(qe4.smaller(), -1.5f, epsilon);
0050   EXPECT_NEAR(qe4.larger(), -1.f, epsilon);
0051
0052   detail::quadratic_equation<scalar> qe5{2.f, 5.f, -3.f};
0053
0054   ASSERT_EQ(qe5.solutions(), 2);
0055   EXPECT_NEAR(qe5.smaller(), -3.f, epsilon);
0056   EXPECT_NEAR(qe5.larger(), 0.5f, epsilon);
0057
0058   detail::quadratic_equation<scalar> qe6{2.f, -5.f, 3.f};
0059
0060   ASSERT_EQ(qe6.solutions(), 2);
0061   EXPECT_NEAR(qe6.smaller(), 1.f, epsilon);
0062   EXPECT_NEAR(qe6.larger(), 1.5f, epsilon);
0063
0064   detail::quadratic_equation<scalar> qe7{2.f, -5.f, -3.f};
0065
0066   ASSERT_EQ(qe7.solutions(), 2);
0067   EXPECT_NEAR(qe7.smaller(), -0.5f, epsilon);
0068   EXPECT_NEAR(qe7.larger(), 3.f, epsilon);
0069
0070   detail::quadratic_equation<scalar> qe8{2.f, -5.f, 0.f};
0071
0072   ASSERT_EQ(qe8.solutions(), 2);
0073   EXPECT_NEAR(qe8.smaller(), 0.f, epsilon);
0074   EXPECT_NEAR(qe8.larger(), 5.f / 2.f, epsilon);
0075 }