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Struct template lazy_variance_impl

boost::accumulators::impl::lazy_variance_impl — Lazy calculation of variance.


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

template<typename Sample, typename MeanFeature> 
struct lazy_variance_impl {
  // types
  typedef numeric::functional::average< Sample, std::size_t >::result_type result_type;

  // construct/copy/destruct

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


Default sample variance implementation based on the second moment moment<2>, mean and count.

Equation 1.21. 


Equation 1.22. 

is the estimate of the sample mean and is the number of samples.

lazy_variance_impl public construct/copy/destruct

  1. lazy_variance_impl(dont_care);

lazy_variance_impl public member functions

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