Browse Source

fix bug in interpolation (#29)

main
zhenfei 2 years ago
committed by GitHub
parent
commit
dfb2066a79
No known key found for this signature in database GPG Key ID: 4AEE18F83AFDEB23
1 changed files with 49 additions and 6 deletions
  1. +49
    -6
      poly-iop/src/sum_check/verifier.rs

+ 49
- 6
poly-iop/src/sum_check/verifier.rs

@ -281,18 +281,18 @@ fn interpolate_uni_poly(p_i: &[F], eval_at: F) -> Result
/// compute the factorial(a) = 1 * 2 * ... * a
#[inline]
fn field_factorial<F: PrimeField>(a: usize) -> F {
let mut res = 1u64;
for i in 1..=a {
res *= i as u64;
let mut res = F::one();
for i in 2..=a {
res *= F::from(i as u64);
}
F::from(res)
res
}
/// compute the factorial(a) = 1 * 2 * ... * a
#[inline]
fn u128_factorial(a: usize) -> u128 {
let mut res = 1u128;
for i in 1..=a {
for i in 2..=a {
res *= i as u128;
}
res
@ -302,8 +302,51 @@ fn u128_factorial(a: usize) -> u128 {
#[inline]
fn u64_factorial(a: usize) -> u64 {
let mut res = 1u64;
for i in 1..=a {
for i in 2..=a {
res *= i as u64;
}
res
}
#[cfg(test)]
mod test {
use super::interpolate_uni_poly;
use crate::errors::PolyIOPErrors;
use ark_bls12_381::Fr;
use ark_poly::{univariate::DensePolynomial, Polynomial, UVPolynomial};
use ark_std::{vec::Vec, UniformRand};
#[test]
fn test_interpolation() -> Result<(), PolyIOPErrors> {
let mut prng = ark_std::test_rng();
// test a polynomial with 20 known points, i.e., with degree 19
let poly = DensePolynomial::<Fr>::rand(20 - 1, &mut prng);
let evals = (0..20)
.map(|i| poly.evaluate(&Fr::from(i)))
.collect::<Vec<Fr>>();
let query = Fr::rand(&mut prng);
assert_eq!(poly.evaluate(&query), interpolate_uni_poly(&evals, query)?);
// test a polynomial with 33 known points, i.e., with degree 32
let poly = DensePolynomial::<Fr>::rand(33 - 1, &mut prng);
let evals = (0..33)
.map(|i| poly.evaluate(&Fr::from(i)))
.collect::<Vec<Fr>>();
let query = Fr::rand(&mut prng);
assert_eq!(poly.evaluate(&query), interpolate_uni_poly(&evals, query)?);
// test a polynomial with 64 known points, i.e., with degree 63
let poly = DensePolynomial::<Fr>::rand(64 - 1, &mut prng);
let evals = (0..64)
.map(|i| poly.evaluate(&Fr::from(i)))
.collect::<Vec<Fr>>();
let query = Fr::rand(&mut prng);
assert_eq!(poly.evaluate(&query), interpolate_uni_poly(&evals, query)?);
Ok(())
}
}

Loading…
Cancel
Save