** REQUIREMENTS

Ruby 2.2.2 or higher

** Installation

#+begin_src bash
gem install statistics3
#+end_src

** Documentation

Note that I've just modernized this fork, and will attempt 
to add more documentation as time permits.

*** List of all available functions

*** Distribution

**** Normal Distribution

| Integral of normal distribution over (-Infty, x].               | normalxXX_(z) |
| Integral of normal distribution over [0, x].                    | normal__X_(z) |
| Integral of normal distribution over [x, Infty).                | normal___x(z) |
| Integral of normal distribution over (-Infty, -x] + [x, Infty). | normalx__x(z) |

**** Inverse of normal-distribution

| P-value of the corresponding integral. | pnormalxXX_(z) |
| P-value of the corresponding integral. | pnormal__X_(y) |
| P-value of the corresponding integral. | pnormal___x(y) |
| P-value of the corresponding integral. | pnormalx__x(y) |

**** Chi2-distribution

| Integral of Chi-squared distribution with n degrees of freedom over [x, Infty). | chi2_x(n, x) |
| Integral of Chi-squared distribution with n degrees of freedom over [0, x].     | chi2X_(n, x) |

**** Inverse of chi2-distribution

| P-value of the corresponding integral. | pchi2_x(n, y) |
| P-value of the corresponding integral. | pchi2X_(n, y) |

**** t-distribution

| Integral of normal distribution with n degrees of freedom over (-Infty, -x] + [x, Infty). | tx__x(n, x) |
| Integral of t-distribution with n degrees of freedom over (-Infty, x].                    | txXX_(n, x) |
| Integral of t-distribution with n degrees of freedom over [0, x].                         | t__X_(n, x) |
| Integral of t-distribution with n degrees of freedom over [x, Infty).                     | t___x(n, x) |

**** inverse of t-distribution

| P-value of the corresponding integral. | ptx__x(n, y) |
| P-value of the corresponding integral. | ptxXX_(n, y) |
| P-value of the corresponding integral. | pt__X_(n, y) |
| P-value of the corresponding integral. | pt___x(n, y) |

**** F-distribution

| Integral of F-distribution with n1 and n2 degrees of freedom over [x, Infty). | f_x(n1, n2, x) |
| Integral of F-distribution with n1 and n2 degrees of freedom over [0, x].     | fX_(n1, n2, x) |

**** Inverse of F-distribution

| P-value of the corresponding integral. | pf_x(n1, n2, x) |
| P-value of the corresponding integral. | pfX_(n1, n2, x) |

**** Discrete distributions

- binX_(n, p, x)
- bin_x(n, p, x)
- poissonX_(m, x)
- poisson_x(m, x)

** Usage *** Example:

#+begin_src ruby
require "statistics3"
puts Statistics3.normaldist(0.27) #=> 0.60641987319804
#+end_src

** If you don't want to use the C extension:

#+begin_src ruby
require "statistics3/no_ext"
puts Statistics3.normaldist(0.27) #=> 0.606419873198039 (delta of 9.99200722162641e-16)
#+end_src

** LICENSE:

MIT