Expand description
Student-t quantile used for confidence-interval multipliers.
With the regression feature the quantile is computed by
anofox-regression (statrs::StudentsT). Without it, a self-contained
inversion of the t CDF (regularised incomplete beta, bisection) gives the
same value to ~1e-10 — before #414 this fell back to the normal 1.96 for
every p and df, so small-sample intervals were too narrow.
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.