private: value_type do_half_width() const
{
if (this->num_observations() > 1)
{
uint_type n(this->num_observations());
::dcs::math::stats::students_t_distribution<value_type> t_dist(n-1);
value_type t(::dcs::math::stats::quantile(t_dist, (1+this->confidence_interval())/value_type(2)));
value_type q(this->estimate());
return t*::std::sqrt(q*(1-q)/(this->num_observations()-1));
}
return ::dcs::math::constants::infinity<value_type>::value;
}
private: value_type do_half_width() const
{
if (count_ > 1)
{
::dcs::math::stats::students_t_distribution<value_type> t_dist(count_-1);
value_type t = ::dcs::math::stats::quantile(t_dist, (value_type(1)+ci_level_)/value_type(2));
//return ::std::sqrt(this->variance()/count_)*t;
return t*(this->standard_deviation()/::std::sqrt(count_));
}
//return value_type/*zero*/();
return ::dcs::math::constants::infinity<value_type>::value;
}
double TConfidenceInterval(double stddev, int size, double p) {
boost::math::students_t t_dist(size - 1);
double t_val = boost::math::quantile(
boost::math::complement(t_dist, (1 - p) / 2));
return t_val * stddev / sqrt(size);
}