root_solve.hpp

// ops/root_solve.hpp
//
// Scalar / low-dim iterative solver KERNELS (raw double precision, FnHandle
// objective) — the numerical core behind fzero / fminbnd / fminsearch. Core-free
// (value layer only); the toolbox Value-API wrappers and the engine adapters live
// above. Solver kernels belong in ops per LAYERING_TARGET_ARCHITECTURE §2/§3/§9.
 
#pragma once
 
#include <cstddef>
#include <memory_resource>
#include <nk/value/fn_handle.hpp>
#include <nk/value/scratch.hpp>
#include <utility>
 
namespace nk::ops {

std::pair<double, double> findBracket(FnHandle fn, double x0, std::pmr::memory_resource *mr);

double brent(FnHandle fn, double a, double b, std::pmr::memory_resource *mr);

double brentMin(FnHandle fn, double a, double b, double tol, std::pmr::memory_resource *mr);

ScratchVec<double> nelderMead(FnHandle fn, const double *x0, std::size_t n, double tol,
                              std::pmr::memory_resource *mr);
 
} // namespace nk::ops