Struct MonotoneRootSolution 

pub struct MonotoneRootSolution {
    pub root: f64,
    pub abs_deriv: f64,
    pub residual: f64,
    pub refine_iters: usize,
}

Shared hybrid bracketing + Newton solver for strictly monotone calibration equations F(a) = 0.

eval(a) must return (F(a), F'(a), F''(a)). The second derivative feeds the safeguarded Halley step inside the shared solver.

The algorithm core lives in opt::find_root_monotone (warm-start Newton probes → analytic-or-geometric bracket → hybrid Halley/Newton/bisection refinement with best-point tracking); this module is the thin domain wrapper that keeps the calibration-facing signature, threads the label context through, and maps opt::RootError back onto MonotoneRootError’s byte-identical Display shapes.

Returns (root, |F'(root)|, F(root)). The absolute derivative is always positive and can be used directly as the density-normalising calibration derivative. Callers must validate the residual against the scale of their calibration equation.

The monotone direction (increasing vs decreasing) is inferred from the sign of F’(a) at the initial point, so the same code handles both the Bernoulli case (F increasing) and the survival case (F decreasing).

Fields

root: f64

abs_deriv: f64

residual: f64

refine_iters: usize

Trait Implementations

impl Clone for MonotoneRootSolution

fn clone(&self) -> MonotoneRootSolution

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Copy for MonotoneRootSolution

impl Debug for MonotoneRootSolution

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.