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  1. // Ceres Solver - A fast non-linear least squares minimizer
  2. // Copyright 2015 Google Inc. All rights reserved.
  3. // http://ceres-solver.org/
  4. //
  5. // Redistribution and use in source and binary forms, with or without
  6. // modification, are permitted provided that the following conditions are met:
  7. //
  8. // * Redistributions of source code must retain the above copyright notice,
  9. // this list of conditions and the following disclaimer.
  10. // * Redistributions in binary form must reproduce the above copyright notice,
  11. // this list of conditions and the following disclaimer in the documentation
  12. // and/or other materials provided with the distribution.
  13. // * Neither the name of Google Inc. nor the names of its contributors may be
  14. // used to endorse or promote products derived from this software without
  15. // specific prior written permission.
  16. //
  17. // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
  18. // AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  19. // IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  20. // ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
  21. // LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
  22. // CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
  23. // SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
  24. // INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
  25. // CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  26. // ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  27. // POSSIBILITY OF SUCH DAMAGE.
  28. //
  29. // Author: keir@google.com (Keir Mierle)
  30. //
  31. // Minimize 0.5 (10 - x)^2 using jacobian matrix computed using
  32. // numeric differentiation.
  33. #include "ceres/ceres.h"
  34. #include "glog/logging.h"
  35. using ceres::NumericDiffCostFunction;
  36. using ceres::CENTRAL;
  37. using ceres::CostFunction;
  38. using ceres::Problem;
  39. using ceres::Solver;
  40. using ceres::Solve;
  41. // A cost functor that implements the residual r = 10 - x.
  42. struct CostFunctor {
  43. bool operator()(const double* const x, double* residual) const {
  44. residual[0] = 10.0 - x[0];
  45. return true;
  46. }
  47. };
  48. int main(int argc, char** argv) {
  49. google::InitGoogleLogging(argv[0]);
  50. // The variable to solve for with its initial value. It will be
  51. // mutated in place by the solver.
  52. double x = 0.5;
  53. const double initial_x = x;
  54. // Build the problem.
  55. Problem problem;
  56. // Set up the only cost function (also known as residual). This uses
  57. // numeric differentiation to obtain the derivative (jacobian).
  58. CostFunction* cost_function =
  59. new NumericDiffCostFunction<CostFunctor, CENTRAL, 1, 1> (new CostFunctor);
  60. problem.AddResidualBlock(cost_function, NULL, &x);
  61. // Run the solver!
  62. Solver::Options options;
  63. options.minimizer_progress_to_stdout = true;
  64. Solver::Summary summary;
  65. Solve(options, &problem, &summary);
  66. std::cout << summary.BriefReport() << "\n";
  67. std::cout << "x : " << initial_x
  68. << " -> " << x << "\n";
  69. return 0;
  70. }