| // Ceres Solver - A fast non-linear least squares minimizer | 
 | // Copyright 2022 Google Inc. All rights reserved. | 
 | // http://ceres-solver.org/ | 
 | // | 
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 | // POSSIBILITY OF SUCH DAMAGE. | 
 | // | 
 | // Author: sameeragarwal@google.com (Sameer Agarwal) | 
 | //         tbennun@gmail.com (Tal Ben-Nun) | 
 |  | 
 | #include "ceres/numeric_diff_test_utils.h" | 
 |  | 
 | #include <algorithm> | 
 | #include <cmath> | 
 |  | 
 | #include "ceres/cost_function.h" | 
 | #include "ceres/test_util.h" | 
 | #include "ceres/types.h" | 
 | #include "gtest/gtest.h" | 
 |  | 
 | namespace ceres::internal { | 
 |  | 
 | bool EasyFunctor::operator()(const double* x1, | 
 |                              const double* x2, | 
 |                              double* residuals) const { | 
 |   residuals[0] = residuals[1] = residuals[2] = 0; | 
 |   for (int i = 0; i < 5; ++i) { | 
 |     residuals[0] += x1[i] * x2[i]; | 
 |     residuals[2] += x2[i] * x2[i]; | 
 |   } | 
 |   residuals[1] = residuals[0] * residuals[0]; | 
 |   return true; | 
 | } | 
 |  | 
 | void EasyFunctor::ExpectCostFunctionEvaluationIsNearlyCorrect( | 
 |     const CostFunction& cost_function, NumericDiffMethodType method) const { | 
 |   // The x1[0] is made deliberately small to test the performance near zero. | 
 |   // clang-format off | 
 |   double x1[] = { 1e-64, 2.0, 3.0, 4.0, 5.0 }; | 
 |   double x2[] = { 9.0, 9.0, 5.0, 5.0, 1.0 }; | 
 |   double *parameters[] = { &x1[0], &x2[0] }; | 
 |   // clang-format on | 
 |  | 
 |   double dydx1[15];  // 3 x 5, row major. | 
 |   double dydx2[15];  // 3 x 5, row major. | 
 |   double* jacobians[2] = {&dydx1[0], &dydx2[0]}; | 
 |  | 
 |   double residuals[3] = {-1e-100, -2e-100, -3e-100}; | 
 |  | 
 |   ASSERT_TRUE( | 
 |       cost_function.Evaluate(¶meters[0], &residuals[0], &jacobians[0])); | 
 |  | 
 |   double expected_residuals[3]; | 
 |   EasyFunctor functor; | 
 |   functor(x1, x2, expected_residuals); | 
 |   EXPECT_EQ(expected_residuals[0], residuals[0]); | 
 |   EXPECT_EQ(expected_residuals[1], residuals[1]); | 
 |   EXPECT_EQ(expected_residuals[2], residuals[2]); | 
 |  | 
 |   double tolerance = 0.0; | 
 |   switch (method) { | 
 |     default: | 
 |     case CENTRAL: | 
 |       tolerance = 3e-9; | 
 |       break; | 
 |  | 
 |     case FORWARD: | 
 |       tolerance = 2e-5; | 
 |       break; | 
 |  | 
 |     case RIDDERS: | 
 |       tolerance = 1e-13; | 
 |       break; | 
 |   } | 
 |  | 
 |   for (int i = 0; i < 5; ++i) { | 
 |     // clang-format off | 
 |     ExpectClose(x2[i],                    dydx1[5 * 0 + i], tolerance);  // y1 | 
 |     ExpectClose(x1[i],                    dydx2[5 * 0 + i], tolerance); | 
 |     ExpectClose(2 * x2[i] * residuals[0], dydx1[5 * 1 + i], tolerance);  // y2 | 
 |     ExpectClose(2 * x1[i] * residuals[0], dydx2[5 * 1 + i], tolerance); | 
 |     ExpectClose(0.0,                      dydx1[5 * 2 + i], tolerance);  // y3 | 
 |     ExpectClose(2 * x2[i],                dydx2[5 * 2 + i], tolerance); | 
 |     // clang-format on | 
 |   } | 
 | } | 
 |  | 
 | bool TranscendentalFunctor::operator()(const double* x1, | 
 |                                        const double* x2, | 
 |                                        double* residuals) const { | 
 |   double x1x2 = 0; | 
 |   for (int i = 0; i < 5; ++i) { | 
 |     x1x2 += x1[i] * x2[i]; | 
 |   } | 
 |   residuals[0] = sin(x1x2); | 
 |   residuals[1] = exp(-x1x2 / 10); | 
 |   return true; | 
 | } | 
 |  | 
 | void TranscendentalFunctor::ExpectCostFunctionEvaluationIsNearlyCorrect( | 
 |     const CostFunction& cost_function, NumericDiffMethodType method) const { | 
 |   struct TestParameterBlocks { | 
 |     double x1[5]; | 
 |     double x2[5]; | 
 |   }; | 
 |  | 
 |   // clang-format off | 
 |   std::vector<TestParameterBlocks> kTests =  { | 
 |     { { 1.0, 2.0, 3.0, 4.0, 5.0 },  // No zeros. | 
 |       { 9.0, 9.0, 5.0, 5.0, 1.0 }, | 
 |     }, | 
 |     { { 0.0, 2.0, 3.0, 0.0, 5.0 },  // Some zeros x1. | 
 |       { 9.0, 9.0, 5.0, 5.0, 1.0 }, | 
 |     }, | 
 |     { { 1.0, 2.0, 3.0, 1.0, 5.0 },  // Some zeros x2. | 
 |       { 0.0, 9.0, 0.0, 5.0, 0.0 }, | 
 |     }, | 
 |     { { 0.0, 0.0, 0.0, 0.0, 0.0 },  // All zeros x1. | 
 |       { 9.0, 9.0, 5.0, 5.0, 1.0 }, | 
 |     }, | 
 |     { { 1.0, 2.0, 3.0, 4.0, 5.0 },  // All zeros x2. | 
 |       { 0.0, 0.0, 0.0, 0.0, 0.0 }, | 
 |     }, | 
 |     { { 0.0, 0.0, 0.0, 0.0, 0.0 },  // All zeros. | 
 |       { 0.0, 0.0, 0.0, 0.0, 0.0 }, | 
 |     }, | 
 |   }; | 
 |   // clang-format on | 
 |  | 
 |   for (auto& test : kTests) { | 
 |     double* x1 = &(test.x1[0]); | 
 |     double* x2 = &(test.x2[0]); | 
 |     double* parameters[] = {x1, x2}; | 
 |  | 
 |     double dydx1[10]; | 
 |     double dydx2[10]; | 
 |     double* jacobians[2] = {&dydx1[0], &dydx2[0]}; | 
 |  | 
 |     double residuals[2]; | 
 |  | 
 |     ASSERT_TRUE( | 
 |         cost_function.Evaluate(¶meters[0], &residuals[0], &jacobians[0])); | 
 |     double x1x2 = 0; | 
 |     for (int i = 0; i < 5; ++i) { | 
 |       x1x2 += x1[i] * x2[i]; | 
 |     } | 
 |  | 
 |     double tolerance = 0.0; | 
 |     switch (method) { | 
 |       default: | 
 |       case CENTRAL: | 
 |         tolerance = 2e-7; | 
 |         break; | 
 |  | 
 |       case FORWARD: | 
 |         tolerance = 2e-5; | 
 |         break; | 
 |  | 
 |       case RIDDERS: | 
 |         tolerance = 3e-12; | 
 |         break; | 
 |     } | 
 |  | 
 |     for (int i = 0; i < 5; ++i) { | 
 |       // clang-format off | 
 |       ExpectClose( x2[i] * cos(x1x2),              dydx1[5 * 0 + i], tolerance); | 
 |       ExpectClose( x1[i] * cos(x1x2),              dydx2[5 * 0 + i], tolerance); | 
 |       ExpectClose(-x2[i] * exp(-x1x2 / 10.) / 10., dydx1[5 * 1 + i], tolerance); | 
 |       ExpectClose(-x1[i] * exp(-x1x2 / 10.) / 10., dydx2[5 * 1 + i], tolerance); | 
 |       // clang-format on | 
 |     } | 
 |   } | 
 | } | 
 |  | 
 | bool ExponentialFunctor::operator()(const double* x1, double* residuals) const { | 
 |   residuals[0] = exp(x1[0]); | 
 |   return true; | 
 | } | 
 |  | 
 | void ExponentialFunctor::ExpectCostFunctionEvaluationIsNearlyCorrect( | 
 |     const CostFunction& cost_function) const { | 
 |   // Evaluating the functor at specific points for testing. | 
 |   std::vector<double> kTests = {1.0, 2.0, 3.0, 4.0, 5.0}; | 
 |  | 
 |   // Minimal tolerance w.r.t. the cost function and the tests. | 
 |   const double kTolerance = 2e-14; | 
 |  | 
 |   for (double& test : kTests) { | 
 |     double* parameters[] = {&test}; | 
 |     double dydx; | 
 |     double* jacobians[1] = {&dydx}; | 
 |     double residual; | 
 |  | 
 |     ASSERT_TRUE( | 
 |         cost_function.Evaluate(¶meters[0], &residual, &jacobians[0])); | 
 |  | 
 |     double expected_result = exp(test); | 
 |  | 
 |     // Expect residual to be close to exp(x). | 
 |     ExpectClose(residual, expected_result, kTolerance); | 
 |  | 
 |     // Check evaluated differences. dydx should also be close to exp(x). | 
 |     ExpectClose(dydx, expected_result, kTolerance); | 
 |   } | 
 | } | 
 |  | 
 | bool RandomizedFunctor::operator()(const double* x1, double* residuals) const { | 
 |   double random_value = uniform_distribution_(*prng_); | 
 |   residuals[0] = x1[0] * x1[0] + random_value; | 
 |   return true; | 
 | } | 
 |  | 
 | void RandomizedFunctor::ExpectCostFunctionEvaluationIsNearlyCorrect( | 
 |     const CostFunction& cost_function) const { | 
 |   std::vector<double> kTests = {0.0, 1.0, 3.0, 4.0, 50.0}; | 
 |  | 
 |   const double kTolerance = 2e-4; | 
 |  | 
 |   for (double& test : kTests) { | 
 |     double* parameters[] = {&test}; | 
 |     double dydx; | 
 |     double* jacobians[1] = {&dydx}; | 
 |     double residual; | 
 |  | 
 |     ASSERT_TRUE( | 
 |         cost_function.Evaluate(¶meters[0], &residual, &jacobians[0])); | 
 |  | 
 |     // Expect residual to be close to x^2 w.r.t. noise factor. | 
 |     ExpectClose(residual, test * test, noise_factor_); | 
 |  | 
 |     // Check evaluated differences. (dy/dx = ~2x) | 
 |     ExpectClose(dydx, 2 * test, kTolerance); | 
 |   } | 
 | } | 
 |  | 
 | }  // namespace ceres::internal |