// Ceres Solver - A fast non-linear least squares minimizer
// Copyright 2012 Google Inc. All rights reserved.
// http://code.google.com/p/ceres-solver/
//
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// modification, are permitted provided that the following conditions are met:
//
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//   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.
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//   used to endorse or promote products derived from this software without
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//
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// Author: sameeragarwal@google.com (Sameer Agarwal)

#ifndef CERES_INTERNAL_TRUST_REGION_MINIMIZER_H_
#define CERES_INTERNAL_TRUST_REGION_MINIMIZER_H_

#include "ceres/minimizer.h"
#include "ceres/solver.h"
#include "ceres/types.h"

namespace ceres {
namespace internal {

// Generic trust region minimization algorithm. The heavy lifting is
// done by a TrustRegionStrategy object passed in as part of options.
//
// For example usage, see SolverImpl::Minimize.
class TrustRegionMinimizer : public Minimizer {
 public:
  ~TrustRegionMinimizer() {}
  virtual void Minimize(const Minimizer::Options& options,
                        double* parameters,
                        Solver::Summary* summary);

 private:
  void Init(const Minimizer::Options& options);
  void EstimateScale(const SparseMatrix& jacobian, double* scale) const;
  bool MaybeDumpLinearLeastSquaresProblem(const int iteration,
                                          const SparseMatrix* jacobian,
                                          const double* residuals,
                                          const double* step) const;

  Minimizer::Options options_;
};

}  // namespace internal
}  // namespace ceres
#endif  // CERES_INTERNAL_TRUST_REGION_MINIMIZER_H_
