// Ceres Solver - A fast non-linear least squares minimizer

// Copyright 2015 Google Inc. All rights reserved.

// http://ceres-solver.org/

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// Author: sameeragarwal@google.com (Sameer Agarwal)

#ifndef CERES_INTERNAL_LINE_SEARCH_MINIMIZER_H_

#define CERES_INTERNAL_LINE_SEARCH_MINIMIZER_H_

#include "ceres/minimizer.h"

#include "ceres/solver.h"

#include "ceres/types.h"

#include "ceres/internal/eigen.h"

#include "glog/logging.h"

namespace ceres {

namespace internal {

// Generic line search minimization algorithm.

//

// For example usage, see SolverImpl::Minimize.

class LineSearchMinimizer : public Minimizer {

 public:

  struct State {

    State(int num_parameters,

          int num_effective_parameters)

        : cost(0.0),

          gradient(num_effective_parameters),

          gradient_squared_norm(0.0),

          search_direction(num_effective_parameters),

          directional_derivative(0.0),

          step_size(0.0) {

    }

    double cost;

    Vector gradient;

    double gradient_squared_norm;

    double gradient_max_norm;

    Vector search_direction;

    double directional_derivative;

    double step_size;

  };

  ~LineSearchMinimizer() {}

  virtual void Minimize(const Minimizer::Options& options,

                        double* parameters,

                        Solver::Summary* summary);

};

}  // namespace internal

}  // namespace ceres

#endif  // CERES_INTERNAL_LINE_SEARCH_MINIMIZER_H_