//! Main components:
//! - `UniPoly`: an univariate dense polynomial in coefficient form (big endian),
//! - `CompressedUniPoly`: a univariate dense polynomial, compressed (omitted linear term), in coefficient form (little endian),
@@ -308,6 +358,7 @@
};
use ff::PrimeField;
+use rand::{CryptoRng, RngCore};
use rayon::prelude::{IntoParallelIterator, IntoParallelRefMutIterator, ParallelIterator};
use ref_cast::RefCast;
use serde::{Deserialize, Serialize};
@@ -445,6 +496,15 @@
coeffs_except_linear_term,
}
}
+
+ /// Returns a random polynomial
+ pub fn random<R: RngCore + CryptoRng>(num_vars: usize, mut rng: &mut R) -> Self {
+ Self::new(
+ std::iter::from_fn(|| Some(Scalar::random(&mut rng)))
+ .take(num_vars)
+ .collect(),
+ )
+ }
}
impl<Scalar: PrimeField> CompressedUniPoly<Scalar> {
@@ -530,6 +590,8 @@
mod tests {
use super::*;
use crate::provider::{bn256_grumpkin, secp_secq::secp256k1};
+ use rand::SeedableRng;
+ use rand_chacha::ChaCha20Rng;
fn test_from_evals_quad_with<F: PrimeField>() {
// polynomial is 2x^2 + 3x + 1
@@ -598,5 +660,43 @@
test_from_evals_cubic_with::<bn256_grumpkin::bn256::Scalar>();
test_from_evals_cubic_with::<secp256k1::Scalar>()
}
+
+ /// Perform a naive n^2 multiplication of `self` by `other`.
+ pub fn naive_mul<F: PrimeField>(ours: &UniPoly<F>, other: &UniPoly<F>) -> UniPoly<F> {
+ if ours.is_zero() || other.is_zero() {
+ UniPoly::zero()
+ } else {
+ let mut result = vec![F::ZERO; ours.degree() + other.degree() + 1];
+ for (i, self_coeff) in ours.coeffs.iter().enumerate() {
+ for (j, other_coeff) in other.coeffs.iter().enumerate() {
+ result[i + j] += &(*self_coeff * other_coeff);
+ }
+ }
+ UniPoly::new(result)
+ }
+ }
+
+ fn divide_polynomials_random<Fr: PrimeField>() {
+ let rng = &mut ChaCha20Rng::from_seed([0u8; 32]);
+
+ for a_degree in 0..50 {
+ for b_degree in 0..50 {
+ let dividend = UniPoly::<Fr>::random(a_degree, rng);
+ let divisor = UniPoly::<Fr>::random(b_degree, rng);
+ if let Some((quotient, remainder)) = UniPoly::divide_with_q_and_r(÷nd, &divisor) {
+ let mut prod = naive_mul(&divisor, "ient);
+ prod += &remainder;
+ assert_eq!(dividend, prod)
+ }
+ }
+ }
+ }
+
+ #[test]
+ fn test_divide_polynomials_random() {
+ divide_polynomials_random::<pasta_curves::pallas::Scalar>();
+ divide_polynomials_random::<bn256_grumpkin::bn256::Scalar>();
+ divide_polynomials_random::<secp256k1::Scalar>()
+ }
}