Struct template lazy_variance_impl

Boost C++ Libraries

Struct template lazy_variance_impl

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

Synopsis

// 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
  lazy_variance_impl(dont_care);

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

Description

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

Equation 1.21.

where

Equation 1.22.

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

`lazy_variance_impl` public construct/copy/destruct

```
lazy_variance_impl(dont_care);
```

`lazy_variance_impl` public member functions

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