Module dist 

Student-t quantile used for confidence-interval multipliers.

Per this crate’s rule (no statistical calculation lives here), the quantile itself is computed by anofox-regression (statrs::StudentsT) when the regression feature is enabled. Without that feature there is no distribution library available, so we fall back to the large-sample normal 97.5% quantile 1.96 — enable regression for exact qt(p, df).

Functions

ellipse_radius

See the regression-enabled variant; this uses the χ²₂ closed form.

qnorm

See the regression-enabled variant; this is the Abramowitz & Stegun rational approximation used when no distribution library is available.

qt

See the regression-enabled variant above; without a distribution library this returns the large-sample normal 0.975 quantile.