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Struct template density_impl

boost::accumulators::impl::density_impl — Histogram density estimator.


// In header: <boost/accumulators/statistics/density.hpp>

template<typename Sample> 
struct density_impl {
  // types
  typedef numeric::functional::average< Sample, std::size_t >::result_type float_type;    
  typedef std::vector< std::pair< float_type, float_type > >               histogram_type;
  typedef std::vector< float_type >                                        array_type;    
  typedef iterator_range< typename histogram_type::iterator >              result_type;   

  // construct/copy/destruct
  template<typename Args> density_impl(Args const &);

  // public member functions
  template<typename Args> void operator()(Args const &) ;
  template<typename Args> result_type result(Args const &) const;


The histogram density estimator returns a histogram of the sample distribution. The positions and sizes of the bins are determined using a specifiable number of cached samples (cache_size). The range between the minimum and the maximum of the cached samples is subdivided into a specifiable number of bins (num_bins) of same size. Additionally, an under- and an overflow bin is added to capture future under- and overflow samples. Once the bins are determined, the cached samples and all subsequent samples are added to the correct bins. At the end, a range of std::pair is return, where each pair contains the position of the bin (lower bound) and the samples count (normalized with the total number of samples).

density_impl public construct/copy/destruct

  1. template<typename Args> density_impl(Args const & args);

density_impl public member functions

  1. template<typename Args> void operator()(Args const & args) ;
  2. template<typename Args> result_type result(Args const & args) const;