Struct Polynomial 

pub struct Polynomial { /* private fields */ }

A real polynomial a[0] + a[1] x + ... + a[n] x^n with finite coefficients.

Implementations

impl Polynomial

pub fn new(coefficients: &[f64]) -> NumericResult<Self>

A polynomial from coefficients in ascending order of power. Trailing zero coefficients are dropped.

Errors

Refuses a non-finite coefficient.

pub fn from_roots(roots: &[f64]) -> NumericResult<Self>

(x - r_0)(x - r_1)..., expanded. A convenience for building test and reference polynomials.

Errors

Refuses a non-finite root or an expansion that overflows.

pub fn coefficients(&self) -> &[f64]

Coefficients in ascending order of power, without trailing zeros.

pub fn degree(&self) -> Option<usize>

Degree, or None for the zero polynomial.

pub fn evaluate(&self, x: f64) -> f64

p(x) by Horner’s rule.

pub fn evaluate_with_bound(&self, x: f64) -> (f64, f64)

p(x) and a rigorous bound on the rounding error of that value.

The bound is gamma(2n + 1) * sum |a_i| |x|^i plus an underflow allowance, where gamma(k) = k u / (1 - k u).

pub fn derivative(&self) -> Polynomial

The derivative.

pub fn real_roots( &self, lower: f64, upper: f64, ) -> NumericResult<Vec<PolynomialRoot>>

Every real root in [lower, upper], in increasing order.

Each entry is either one certified RootKind::Simple root with an enclosure, or an RootKind::Unresolved region with the most roots it can hold. No root of the polynomial in the interval is left out: a root not reported as simple lies in an unresolved region.

Errors

Refuses non-finite bounds, lower > upper, and the zero polynomial (NumericError::ZeroPolynomial).

Trait Implementations

impl Clone for Polynomial

fn clone(&self) -> Self

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for Polynomial

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

Formats the value using the given formatter.

impl PartialEq for Polynomial

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

Equality operator ==.

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

Inequality operator !=.

impl StructuralPartialEq for Polynomial