diff options
author | Stanislaw Halik <sthalik@misaki.pl> | 2017-05-24 17:22:30 +0200 |
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committer | Stanislaw Halik <sthalik@misaki.pl> | 2017-05-24 17:22:30 +0200 |
commit | d53099d36986ca7207f507f11d8e9552340f210c (patch) | |
tree | e0931c1f79806631c9dc24953ea03706008fb070 /api | |
parent | 0aa16cfcd724f6907a27d9e1e57f34f0d09deb4a (diff) |
api/variance: move to compat/
Diffstat (limited to 'api')
-rw-r--r-- | api/variance.hpp | 57 |
1 files changed, 0 insertions, 57 deletions
diff --git a/api/variance.hpp b/api/variance.hpp deleted file mode 100644 index 7a83154c..00000000 --- a/api/variance.hpp +++ /dev/null @@ -1,57 +0,0 @@ -#pragma once - -#include <cmath> -#include <cinttypes> - -// no copyright information other than the attribution below. - -// code shared as an example/tutorial of running variance -// written by John D. Cook on the website <http://www.johndcook.com/blog/standard_deviation> - -// following references in the site's article: - -// Chan, Tony F.; Golub, Gene H.; LeVeque, Randall J. (1983). -// Algorithms for Computing the Sample Variance: Analysis and Recommendations. -// The American Statistician 37, 242-247. - -// Ling, Robert F. (1974). -// Comparison of Several Algorithms for Computing Sample Means and Variances. -// Journal of the American Statistical Association, Vol. 69, No. 348, 859-866. - -class variance -{ - double m_old, m_new, s_old, s_new; - std::uintptr_t cnt; - -public: - using size_type = std::uintptr_t; - - variance() : cnt(0) {} - - void clear() { *this = variance(); } - - size_type count() { return cnt; } - - void input(double x) - { - cnt++; - - if (cnt == 1) - { - m_old = m_new = x; - s_old = 0; - } - else - { - m_new = m_old + (x - m_old)/cnt; - s_new = s_old + (x - m_old)*(x - m_new); - - m_old = m_new; - s_old = s_new; - } - } - - double avg() const { return cnt > 0 ? m_new : 0; } - double Var() const { return cnt > 1 ? s_new/(cnt - 1) : 0; } - double stddev() const { return std::sqrt(Var()); } -}; |