00001 // This is brl/bbas/bsta/algo/bsta_von_mises_updater.h 00002 #ifndef bsta_von_mises_updater_h_ 00003 #define bsta_von_mises_updater_h_ 00004 //: 00005 // \file 00006 // \brief Von_Mises updaters 00007 // \author Joseph L. Mundy 00008 // \date July 18, 2009 00009 // 00010 // This file contains updaters based on 00011 // Von_Mises distributions 00012 // 00013 // \verbatim 00014 // Modifications 00015 // (none yet) 00016 // \endverbatim 00017 // 00018 // do not remove the following text 00019 // Approved for public release, distribution unlimited (DISTAR Case 14389) 00020 // 00021 00022 #include <bsta/bsta_von_mises.h> 00023 #include <bsta/bsta_attributes.h> 00024 #include <vcl_algorithm.h> 00025 #include <vcl_cmath.h> 00026 #include <vcl_vector.h> 00027 00028 //: A von_mises window updater based on samples of the space of unit vectors. 00029 // Implemented only for vector dimensions 2 and 3. 00030 template <class von_mises_dist_> 00031 class bsta_von_mises_updater 00032 { 00033 public: 00034 typedef typename von_mises_dist_::math_type math_t; 00035 typedef typename von_mises_dist_::vector_type vect_t; 00036 typedef bsta_vsum_num_obs<von_mises_dist_> obs_vm_dist_; 00037 //: for compatibility with vpdl/vpdt 00038 typedef obs_vm_dist_ distribution_type; 00039 enum { data_dimension = von_mises_dist_::data_dimension }; 00040 //: for compatibility with vpdl/vpdt 00041 typedef typename von_mises_dist_::field_type field_type; 00042 00043 // Constructor 00044 // initial_kappa_ is assigned when only one sample has been observed 00045 bsta_von_mises_updater(math_t kappa= math_t(10000)): 00046 initial_kappa_(kappa){} 00047 00048 //: The update functor assuming standard learning rate 00049 void operator ()(obs_vm_dist_& pdist, const vect_t& sample) const{ 00050 pdist.num_observations += math_t(1); 00051 pdist.vector_sum += sample; 00052 this->update(pdist, pdist.vector_sum, math_t(1)/pdist.num_observations); 00053 } 00054 //: The update functor with a learning rate specified 00055 void operator ()(obs_vm_dist_& pdist, const vect_t& sample, math_t alpha) const{ 00056 pdist.num_observations += math_t(1); 00057 pdist.vector_sum += sample; 00058 this->update(pdist, pdist.vector_sum, alpha); 00059 } 00060 private: 00061 void update(obs_vm_dist_& pdist, const vect_t& vsum, math_t alpha) const; 00062 math_t initial_kappa_; 00063 }; 00064 00065 00066 #endif // bsta_von_mises_updater_h_
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