Struct RootSettings 

pub struct RootSettings {
    pub x_tol_abs: f64,
    pub x_tol_rel: f64,
    pub f_tol: f64,
    pub max_iterations: u32,
}

Convergence tolerances and the iteration cap, shared by both iterative solvers.

A lane is converged when either the bracket (bisection, Brent) or the step (Newton) has shrunk to x_tol_abs + x_tol_rel * |x|, or the residual magnitude has fallen to f_tol. An exactly-zero residual always converges regardless of tolerances.

Fields and valid ranges

• x_tol_abs — absolute abscissa tolerance, in the abscissa’s own units. Must be >= 0. Guards the case x ≈ 0, where a purely relative tolerance can never be met.
• x_tol_rel — relative abscissa tolerance, dimensionless, >= 0.
• f_tol — residual tolerance, in the residual’s own units, >= 0. Default 0.0, i.e. disabled: with no knowledge of the residual’s scale, a nonzero default would be a guess. Set it when you know what “small enough” means for your function; leaving it at zero simply means the abscissa tolerance decides.
• max_iterations — hard cap. On reaching it a lane reports RootStatus::MaxIterations and its best iterate. Must be >= 1.

A negative tolerance is not rejected; it simply can never be met, and the lane will report RootStatus::MaxIterations. That is a truthful outcome rather than a silent success.

Defaults

x_tol_abs = 1e-12, x_tol_rel = 1e-12, f_tol = 0.0, max_iterations = 100. One hundred iterations is comfortable for Brent (typically 6-12) and adequate for bisection over any bracket narrower than about 2^100 tolerances.

Example

use outram_foam_basic_lib::math::parallel::RootSettings;

// Struct-update syntax keeps the defaults you did not mean to change.
let s = RootSettings {
    max_iterations: 200,
    ..RootSettings::default()
};
assert_eq!(s.x_tol_rel, 1e-12);
assert_eq!(s.max_iterations, 200);

Fields

x_tol_abs: f64

Absolute abscissa tolerance, in the abscissa’s units. >= 0.

x_tol_rel: f64

Relative abscissa tolerance, dimensionless. >= 0.

f_tol: f64

Residual tolerance, in the residual’s units. 0.0 disables it.

max_iterations: u32

Maximum iterations per lane before reporting RootStatus::MaxIterations. >= 1.

Trait Implementations

impl Clone for RootSettings

fn clone(&self) -> Self

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Copy for RootSettings

impl Debug for RootSettings

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

Formats the value using the given formatter.

impl Default for RootSettings

fn default() -> Self

Returns the “default value” for a type.

impl PartialEq for RootSettings

fn eq(&self, other: &Self) -> bool

Equality operator ==.

fn ne(&self, other: &Rhs) -> bool

Inequality operator !=.

impl StructuralPartialEq for RootSettings