1 // Ceres Solver - A fast non-linear least squares minimizer
2 // Copyright 2015 Google Inc. All rights reserved.
3 // http://ceres-solver.org/
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29 // Author: strandmark@google.com (Petter Strandmark)
31 #include "ceres/gradient_problem.h"
32 #include "ceres/gradient_problem_solver.h"
34 #include "gtest/gtest.h"
39 // Rosenbrock function; see http://en.wikipedia.org/wiki/Rosenbrock_function .
40 class Rosenbrock : public ceres::FirstOrderFunction {
42 virtual ~Rosenbrock() {}
44 virtual bool Evaluate(const double* parameters,
46 double* gradient) const {
47 const double x = parameters[0];
48 const double y = parameters[1];
50 cost[0] = (1.0 - x) * (1.0 - x) + 100.0 * (y - x * x) * (y - x * x);
51 if (gradient != NULL) {
52 gradient[0] = -2.0 * (1.0 - x) - 200.0 * (y - x * x) * 2.0 * x;
53 gradient[1] = 200.0 * (y - x * x);
58 virtual int NumParameters() const { return 2; }
61 TEST(GradientProblemSolver, SolvesRosenbrockWithDefaultOptions) {
62 const double expected_tolerance = 1e-9;
63 double parameters[2] = {-1.2, 0.0};
65 ceres::GradientProblemSolver::Options options;
66 ceres::GradientProblemSolver::Summary summary;
67 ceres::GradientProblem problem(new Rosenbrock());
68 ceres::Solve(options, problem, parameters, &summary);
70 EXPECT_EQ(CONVERGENCE, summary.termination_type);
71 EXPECT_NEAR(1.0, parameters[0], expected_tolerance);
72 EXPECT_NEAR(1.0, parameters[1], expected_tolerance);
75 } // namespace internal