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/
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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 #include "ceres/internal/eigen.h"
35 #include "ceres/line_search_minimizer.h"
36 #include "ceres/types.h"
37 
38 namespace ceres {
39 namespace internal {
40 
41 class LineSearchDirection {
42  public:
43   struct Options {
OptionsOptions44     Options()
45         : num_parameters(0),
46           type(LBFGS),
47           nonlinear_conjugate_gradient_type(FLETCHER_REEVES),
48           function_tolerance(1e-12),
49           max_lbfgs_rank(20),
50           use_approximate_eigenvalue_bfgs_scaling(true) {
51     }
52 
53     int num_parameters;
54     LineSearchDirectionType type;
55     NonlinearConjugateGradientType nonlinear_conjugate_gradient_type;
56     double function_tolerance;
57     int max_lbfgs_rank;
58     bool use_approximate_eigenvalue_bfgs_scaling;
59   };
60 
61   static LineSearchDirection* Create(const Options& options);
62 
~LineSearchDirection()63   virtual ~LineSearchDirection() {}
64   virtual bool NextDirection(const LineSearchMinimizer::State& previous,
65                              const LineSearchMinimizer::State& current,
66                              Vector* search_direction) = 0;
67 };
68 
69 }  // namespace internal
70 }  // namespace ceres
71 
72 #endif  // CERES_INTERNAL_LINE_SEARCH_DIRECTION_H_
73