Struct Polynomial 

pub struct Polynomial {
    pub coeffs: Vec<f64>,
}

A polynomial p(z) = coeffs[0] + coeffs[1]*z + coeffs[2]*z^2 + …

Used to represent continuous functions on the spectrum for the continuous functional calculus (by density of polynomials in C(K)).

Fields

coeffs: Vec<f64>

Coefficients in ascending degree order: coeffs[i] is the coefficient of z^i.

Implementations

impl Polynomial

pub fn new(coeffs: Vec<f64>) -> Self

Create a polynomial from coefficients in ascending degree order.

pub fn zero() -> Self

The zero polynomial.

pub fn constant(c: f64) -> Self

A constant polynomial p(z) = c.

pub fn identity() -> Self

The identity polynomial p(z) = z.

pub fn degree(&self) -> usize

The degree of the polynomial (0 for the zero polynomial).

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

Evaluate the polynomial at a scalar point x using Horner’s method.

pub fn add(&self, other: &Polynomial) -> Polynomial

Add two polynomials.

pub fn multiply(&self, other: &Polynomial) -> Polynomial

Multiply two polynomials via convolution.

pub fn scale(&self, s: f64) -> Polynomial

Scale the polynomial by a constant factor.

pub fn compose(&self, other: &Polynomial) -> Polynomial

Compose two polynomials: compute (self o other)(z) = self(other(z)).

Trait Implementations

impl Clone for Polynomial

fn clone(&self) -> Polynomial

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.