openswmm::findroot Namespace Reference

Typedefs
using	NewtonFunc = std::function< void(double x, double *f, double *df)>
	Newton-Raphson with bisection fallback.
using	RidderFunc = std::function< double(double x)>
	Ridder's method (derivative-free).

Functions
int	newton (double x1, double x2, double *rts, double xacc, const NewtonFunc &func)
double	ridder (double x1, double x2, double xacc, const RidderFunc &func)

Variables
constexpr int	MAXIT = 60
	Maximum iterations.

Typedef Documentation

NewtonFunc

using openswmm::findroot::NewtonFunc = typedef std::function<void(double x, double* f, double* df)>

Newton-Raphson with bisection fallback.

Finds x in [x1, x2] such that f(x) = 0. Requires f(x1) and f(x2) to have opposite signs. Uses Newton steps when reliable, falls back to bisection when Newton would exit the bracket or converge slowly.

Parameters

x1	Left bracket.
x2	Right bracket.
rts	[in/out] Initial guess → root.
xacc	Convergence tolerance (|dx| < xacc).
func	Callback: func(x, &f, &df) sets f=f(x), df=f'(x).

Returns

Number of function evaluations, or 0 if exceeded MAXIT.

RidderFunc

using openswmm::findroot::RidderFunc = typedef std::function<double(double x)>

Ridder's method (derivative-free).

Parameters

x1	Left bracket.
x2	Right bracket.
xacc	Convergence tolerance.
func	Callback: func(x) returns f(x).

Returns

Root value, or -1.0e10 if failed.

Function Documentation

newton()

int openswmm::findroot::newton	(	double	x1,
		double	x2,
		double *	rts,
		double	xacc,
		const NewtonFunc &	func
	)

ridder()

double openswmm::findroot::ridder	(	double	x1,
		double	x2,
		double	xacc,
		const RidderFunc &	func
	)

Variable Documentation

MAXIT

constexpr int openswmm::findroot::MAXIT = 60

constexpr

Maximum iterations.