Struct DerivativeSolution 

pub struct DerivativeSolution { /* private fields */ }

One lane’s scalar derivative, with the diagnostics needed to judge it.

Units

Self::raw_value carries the units of f divided by the units of x — a derivative changes dimension, which is exactly why this module does not try to uom-type the generic form. See the module-level “Units” section. realised_step carries the units of x.

Implementations

impl DerivativeSolution

pub fn derivative(&self) -> Option<f64>

The derivative, only if this lane succeeded.

Returns None for every non-DiffStatus::Ok status, so a caller cannot accidentally consume a NaN as a derivative. The diagnostic number is behind the deliberately-named Self::raw_value.

pub fn raw_value(&self) -> f64

The difference quotient as computed, whatever the status — a diagnostic, not an answer. Frequently NaN.

pub fn realised_step(&self) -> f64

The step actually taken, after the x + h rounding correction described on derivative. Units of x.

This is the denominator that was really divided by, not the h that DiffSettings::step_for asked for, and comparing the two is the cheapest way to see step-size trouble.

pub fn status(&self) -> DiffStatus

Why this lane succeeded or failed.

pub fn is_ok(&self) -> bool

Whether this lane produced a usable derivative.

Trait Implementations

impl Clone for DerivativeSolution

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 DerivativeSolution

impl Debug for DerivativeSolution

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

Formats the value using the given formatter.

impl PartialEq for DerivativeSolution

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

Equality operator ==.

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

Inequality operator !=.

impl StructuralPartialEq for DerivativeSolution