Crate spectrafit_dogleg 

spectrafit-dogleg — Powell’s dogleg trust-region method.

One method on the graph-agnostic spectrafit-trust-region framework: it supplies the DoglegStep subproblem solver (Gauss–Newton / Cauchy interpolation within the trust radius) and a thin minimize entry point; the framework owns the Δ-radius control loop, gain-ratio acceptance and Moré scaling.

Dogleg is a robust, cheap workhorse on mildly nonlinear least-squares problems: it is full Gauss–Newton near the optimum and steepest-descent-like far from it, all via one p×p Cholesky per iteration.

Structs

DoglegStep

Powell’s dogleg trust-region subproblem solver (stateless).

Report

Outcome of a solve. The optimised parameters live in the problem (read via TrustRegionProblem::params); this only carries diagnostics.

TrustRegionConfig

Tuning for a single Δ-radius trust-region solve.

Enums

Termination

Why the solve stopped.

Traits

TrustRegionProblem

A weighted nonlinear least-squares problem driven by the trust-region core.

Functions

minimize

Minimise ½‖r(p)‖² over the free parameters of problem with Powell’s dogleg trust-region method. On return the problem holds the best parameters.