Struct polynom::polynomial::Polynomial

pub struct Polynomial {
    pub coefficients: Vec<f64>,
    pub indeterminate: char,
}

A simple polynomial representation with coefficients and an indeterminate.

Fields

coefficients: Vec<f64>

Coefficients of Polynomial. The index of each coefficient indicates its degree, for example in vec![1, 2], the first value is explicitly 1x^0, the second is 2x^1, etc.

indeterminate: char

The char representation of the indeterminate, eg. f(x) = 1 + 2x

Methods

impl Polynomial

pub fn new(coefficients: Vec<f64>, indeterminate: char) -> Polynomial

Returns a Polynomial from a vector of floats and an indeterminate

Example

use polynom::polynomial::Polynomial;

let polynomial = Polynomial::new(vec![1f64, 2f64, 3f64], 'x');
assert_eq!(polynomial.coefficients, vec![1f64, 2f64, 3f64]);

pub fn from_ints(coefficients: Vec<i64>, indeterminate: char) -> Polynomial

Returns a Polynomial from a vector of integers and an indeterminate

Example

use polynom::polynomial::Polynomial;

let polynomial = Polynomial::from_ints(vec![1, 2, 3], 'x');
assert_eq!(polynomial.coefficients, vec![1f64, 2f64, 3f64]);

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

Adds the same-degree coefficients of other: Polynomial to the coefficients of self, and returns a new Polynomial with the summed coefficients.

Example

use polynom::polynomial::Polynomial;

let a_polynomial = Polynomial::from_ints(vec![1, 2, 3], 'x');
let b_polynomial = Polynomial::from_ints(vec![1, 2, 3], 'x');
 
assert_eq!(a_polynomial.add(b_polynomial).coefficients, vec![2f64, 4f64, 6f64]);

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

Adds the same-degree coefficients of other: Polynomial to the coefficients of self, and returns a new Polynomial with the summed coefficients.

Example

use polynom::polynomial::Polynomial;

let a_polynomial = Polynomial::from_ints(vec![1, 2], 'x');
let b_polynomial = Polynomial::from_ints(vec![2, 4], 'x');
 
assert_eq!(a_polynomial.sub(b_polynomial).coefficients, vec![-1f64, -2f64]);

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

Multiplies the same-degree coefficients of self and other, and returns a Polynomial with the new coefficients.

Example

use polynom::polynomial::Polynomial;

let a_polynomial = Polynomial::from_ints(vec![1, 2], 'x');
let b_polynomial = Polynomial::from_ints(vec![2, 4], 'x');
 
assert_eq!(a_polynomial.multiply(b_polynomial).coefficients, vec![2f64, 8f64, 8f64]);

pub fn evaluate_at(&self, determinate: f64) -> f64

Return the result of evaluating a Polynomial at value determinate

Example

use polynom::polynomial::Polynomial;

let polynomial = Polynomial::new(vec![1f64, 2f64, 3f64], 'x');
assert_eq!(polynomial.evaluate_at(1.0), 6f64)

pub fn as_string(&self) -> String

Return the polynomial represented as a String

Example

use polynom::polynomial::Polynomial;

let polynomial = Polynomial::new(vec![1f64, 2f64, 3f64], 'x');
assert_eq!(polynomial.as_string(), String::from("f(x) = 1 + 2x + 3x^2"))

pub fn degree(&self) -> isize

Return an integer representation of the degree of the Polynomial

Example

use polynom::polynomial::Polynomial;

let polynomial = Polynomial::new(vec![1f64, 2f64, 3f64], 'x');
assert_eq!(polynomial.degree(), 2)

Trait Implementations

impl Debug for Polynomial

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

Formats the value using the given formatter.