1// Ceres Solver - A fast non-linear least squares minimizer
2// Copyright 2012 Google Inc. All rights reserved.
3// http://code.google.com/p/ceres-solver/
4//
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6// modification, are permitted provided that the following conditions are met:
7//
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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
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28//
29// Author: sameeragarwal@google.com (Sameer Agarwal)
30
31#ifndef CERES_INTERNAL_LINE_SEARCH_DIRECTION_H_
32#define CERES_INTERNAL_LINE_SEARCH_DIRECTION_H_
33
34#ifndef CERES_NO_LINE_SEARCH_MINIMIZER
35
36#include "ceres/internal/eigen.h"
37#include "ceres/line_search_minimizer.h"
38#include "ceres/types.h"
39
40namespace ceres {
41namespace internal {
42
43class LineSearchDirection {
44 public:
45  struct Options {
46    Options()
47        : num_parameters(0),
48          type(LBFGS),
49          nonlinear_conjugate_gradient_type(FLETCHER_REEVES),
50          function_tolerance(1e-12),
51          max_lbfgs_rank(20),
52          use_approximate_eigenvalue_bfgs_scaling(true) {
53    }
54
55    int num_parameters;
56    LineSearchDirectionType type;
57    NonlinearConjugateGradientType nonlinear_conjugate_gradient_type;
58    double function_tolerance;
59    int max_lbfgs_rank;
60    bool use_approximate_eigenvalue_bfgs_scaling;
61  };
62
63  static LineSearchDirection* Create(const Options& options);
64
65  virtual ~LineSearchDirection() {}
66  virtual bool NextDirection(const LineSearchMinimizer::State& previous,
67                             const LineSearchMinimizer::State& current,
68                             Vector* search_direction) = 0;
69};
70
71}  // namespace internal
72}  // namespace ceres
73
74#endif  // CERES_NO_LINE_SEARCH_MINIMIZER
75#endif  // CERES_INTERNAL_LINE_SEARCH_DIRECTION_H_
76