| // Ceres Solver - A fast non-linear least squares minimizer |
| // Copyright 2023 Google Inc. All rights reserved. |
| // http://ceres-solver.org/ |
| // |
| // Redistribution and use in source and binary forms, with or without |
| // modification, are permitted provided that the following conditions are met: |
| // |
| // * Redistributions of source code must retain the above copyright notice, |
| // this list of conditions and the following disclaimer. |
| // * 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. |
| // * Neither the name of Google Inc. 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 |
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| // INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN |
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| // ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE |
| // POSSIBILITY OF SUCH DAMAGE. |
| // |
| // Author: sameeragarwal@google.com (Sameer Agarwal) |
| // |
| // Example of minimizing the Rosenbrock function |
| // (https://en.wikipedia.org/wiki/Rosenbrock_function) using |
| // GradientProblemSolver using derivatives computed using numeric |
| // differentiation. |
| |
| #include <iostream> |
| #include <memory> |
| |
| #include "absl/log/initialize.h" |
| #include "ceres/ceres.h" |
| |
| // f(x,y) = (1-x)^2 + 100(y - x^2)^2; |
| struct Rosenbrock { |
| bool operator()(const double* parameters, double* cost) const { |
| const double x = parameters[0]; |
| const double y = parameters[1]; |
| cost[0] = (1.0 - x) * (1.0 - x) + 100.0 * (y - x * x) * (y - x * x); |
| return true; |
| } |
| |
| static std::unique_ptr<ceres::FirstOrderFunction> Create() { |
| constexpr int kNumParameters = 2; |
| return std::make_unique< |
| ceres::NumericDiffFirstOrderFunction<Rosenbrock, |
| ceres::CENTRAL, |
| kNumParameters>>(); |
| } |
| }; |
| |
| int main(int argc, char** argv) { |
| absl::InitializeLog(); |
| |
| double parameters[2] = {-1.2, 1.0}; |
| |
| ceres::GradientProblemSolver::Options options; |
| options.minimizer_progress_to_stdout = true; |
| |
| ceres::GradientProblemSolver::Summary summary; |
| ceres::GradientProblem problem(Rosenbrock::Create()); |
| ceres::Solve(options, problem, parameters, &summary); |
| |
| std::cout << summary.FullReport() << "\n"; |
| std::cout << "Initial x: " << -1.2 << " y: " << 1.0 << "\n"; |
| std::cout << "Final x: " << parameters[0] << " y: " << parameters[1] |
| << "\n"; |
| return 0; |
| } |