ark_poly/evaluations/univariate/
mod.rs

1//! A univariate polynomial represented in evaluations form.
2
3use crate::{
4    univariate::DensePolynomial, DenseUVPolynomial, EvaluationDomain, GeneralEvaluationDomain,
5};
6use ark_ff::{batch_inversion, FftField};
7use ark_serialize::{CanonicalDeserialize, CanonicalSerialize};
8use ark_std::{
9    ops::{Add, AddAssign, Div, DivAssign, Index, Mul, MulAssign, Sub, SubAssign},
10    vec::*,
11};
12
13#[cfg(feature = "parallel")]
14use rayon::prelude::*;
15
16/// Stores a UV polynomial in evaluation form.
17#[derive(Clone, PartialEq, Eq, Hash, Debug, CanonicalSerialize, CanonicalDeserialize)]
18pub struct Evaluations<F: FftField, D: EvaluationDomain<F> = GeneralEvaluationDomain<F>> {
19    /// The evaluations of a polynomial over the domain `D`
20    pub evals: Vec<F>,
21    #[doc(hidden)]
22    domain: D,
23}
24
25impl<F: FftField, D: EvaluationDomain<F>> Evaluations<F, D> {
26    /// Evaluations of the zero polynomial over `domain`.
27    pub fn zero(domain: D) -> Self {
28        Self {
29            evals: vec![F::zero(); domain.size()],
30            domain,
31        }
32    }
33
34    /// Construct `Self` from evaluations and a domain.
35    pub fn from_vec_and_domain(evals: Vec<F>, domain: D) -> Self {
36        Self { evals, domain }
37    }
38
39    /// Interpolate a polynomial from a list of evaluations
40    pub fn interpolate_by_ref(&self) -> DensePolynomial<F> {
41        DensePolynomial::from_coefficients_vec(self.domain.ifft(&self.evals))
42    }
43
44    /// Interpolate a polynomial from a list of evaluations
45    pub fn interpolate(self) -> DensePolynomial<F> {
46        let Self { mut evals, domain } = self;
47        domain.ifft_in_place(&mut evals);
48        DensePolynomial::from_coefficients_vec(evals)
49    }
50
51    /// Return the domain `self` is defined over
52    pub fn domain(&self) -> D {
53        self.domain
54    }
55}
56
57impl<F: FftField, D: EvaluationDomain<F>> Index<usize> for Evaluations<F, D> {
58    type Output = F;
59
60    fn index(&self, index: usize) -> &F {
61        &self.evals[index]
62    }
63}
64
65impl<'a, 'b, F: FftField, D: EvaluationDomain<F>> Mul<&'a Evaluations<F, D>>
66    for &'b Evaluations<F, D>
67{
68    type Output = Evaluations<F, D>;
69
70    #[inline]
71    fn mul(self, other: &'a Evaluations<F, D>) -> Evaluations<F, D> {
72        let mut result = self.clone();
73        result *= other;
74        result
75    }
76}
77
78impl<'a, F: FftField, D: EvaluationDomain<F>> MulAssign<&'a Evaluations<F, D>>
79    for Evaluations<F, D>
80{
81    #[inline]
82    fn mul_assign(&mut self, other: &'a Evaluations<F, D>) {
83        assert_eq!(self.domain, other.domain, "domains are unequal");
84        ark_std::cfg_iter_mut!(self.evals)
85            .zip(&other.evals)
86            .for_each(|(a, b)| *a *= b);
87    }
88}
89
90impl<'a, F: FftField, D: EvaluationDomain<F>> Mul<F> for &'a Evaluations<F, D> {
91    type Output = Evaluations<F, D>;
92
93    #[inline]
94    fn mul(self, elem: F) -> Evaluations<F, D> {
95        let mut result = self.clone();
96        ark_std::cfg_iter_mut!(result.evals).for_each(|e| {
97            *e *= elem;
98        });
99        result
100    }
101}
102
103impl<'a, 'b, F: FftField, D: EvaluationDomain<F>> Add<&'a Evaluations<F, D>>
104    for &'b Evaluations<F, D>
105{
106    type Output = Evaluations<F, D>;
107
108    #[inline]
109    fn add(self, other: &'a Evaluations<F, D>) -> Evaluations<F, D> {
110        let mut result = self.clone();
111        result += other;
112        result
113    }
114}
115
116impl<'a, F: FftField, D: EvaluationDomain<F>> AddAssign<&'a Evaluations<F, D>>
117    for Evaluations<F, D>
118{
119    #[inline]
120    fn add_assign(&mut self, other: &'a Evaluations<F, D>) {
121        assert_eq!(self.domain, other.domain, "domains are unequal");
122        ark_std::cfg_iter_mut!(self.evals)
123            .zip(&other.evals)
124            .for_each(|(a, b)| *a += b);
125    }
126}
127
128impl<'a, 'b, F: FftField, D: EvaluationDomain<F>> Sub<&'a Evaluations<F, D>>
129    for &'b Evaluations<F, D>
130{
131    type Output = Evaluations<F, D>;
132
133    #[inline]
134    fn sub(self, other: &'a Evaluations<F, D>) -> Evaluations<F, D> {
135        let mut result = self.clone();
136        result -= other;
137        result
138    }
139}
140
141impl<'a, F: FftField, D: EvaluationDomain<F>> SubAssign<&'a Evaluations<F, D>>
142    for Evaluations<F, D>
143{
144    #[inline]
145    fn sub_assign(&mut self, other: &'a Evaluations<F, D>) {
146        assert_eq!(self.domain, other.domain, "domains are unequal");
147        ark_std::cfg_iter_mut!(self.evals)
148            .zip(&other.evals)
149            .for_each(|(a, b)| *a -= b);
150    }
151}
152
153impl<'a, 'b, F: FftField, D: EvaluationDomain<F>> Div<&'a Evaluations<F, D>>
154    for &'b Evaluations<F, D>
155{
156    type Output = Evaluations<F, D>;
157
158    #[inline]
159    fn div(self, other: &'a Evaluations<F, D>) -> Evaluations<F, D> {
160        let mut result = self.clone();
161        result /= other;
162        result
163    }
164}
165
166impl<'a, F: FftField, D: EvaluationDomain<F>> DivAssign<&'a Evaluations<F, D>>
167    for Evaluations<F, D>
168{
169    #[inline]
170    fn div_assign(&mut self, other: &'a Evaluations<F, D>) {
171        assert_eq!(self.domain, other.domain, "domains are unequal");
172        let mut other_copy = other.clone();
173        batch_inversion(other_copy.evals.as_mut_slice());
174        ark_std::cfg_iter_mut!(self.evals)
175            .zip(&other_copy.evals)
176            .for_each(|(a, b)| *a *= b);
177    }
178}
ark_poly/evaluations/univariate/mod.rs

ark_poly/evaluations/univariate/
mod.rs
