Module chi_squared 

χ² (chi-squared) distribution — pdf / cdf / quantile + upper-tail p-value, used by the goodness-of-fit and independence tests. CDF is exact via the regularized lower incomplete gamma P(k/2, x/2) (super::special::gammp).

Functions

cdf

cdf P(X ≤ x) = P(k/2, x/2).

pdf

pdf with k > 0 degrees of freedom, x ≥ 0.

quantile

Inverse cdf (quantile) for 0 < p < 1.

upper_p

Upper-tail p-value P(X ≥ x) — the usual χ² test p-value.