Trait FftParameters

pub trait FftParameters:
    'static
    + Send
    + Sync
    + Sized {
    type BigInteger: BigInteger;

    const TWO_ADICITY: u32;
    const TWO_ADIC_ROOT_OF_UNITY: Self::BigInteger;
    const POWERS_OF_ROOTS_OF_UNITY: &'static [Self::BigInteger];
    const SMALL_SUBGROUP_BASE: Option<u32> = None;
    const SMALL_SUBGROUP_BASE_ADICITY: Option<u32> = None;
    const LARGE_SUBGROUP_ROOT_OF_UNITY: Option<Self::BigInteger> = None;
}

A trait that defines parameters for a field that can be used for FFTs.

Required Associated Constants

const TWO_ADICITY: u32

Let N be the size of the multiplicative group defined by the field. Then TWO_ADICITY is the two-adicity of N, i.e. the integer s such that N = 2^s * t for some odd integer t. 2^s * t = MODULUS - 1 with t odd. This is the two-adicity of the prime.

const TWO_ADIC_ROOT_OF_UNITY: Self::BigInteger

2^s root of unity, defined as GENERATOR^t.

const POWERS_OF_ROOTS_OF_UNITY: &'static [Self::BigInteger]

TWO_ADIC_ROOT_OF_UNITY^2^i for i := 0..TWO_ADICITY-1

Provided Associated Constants

const SMALL_SUBGROUP_BASE: Option<u32> = None

An integer b such that there exists a multiplicative subgroup of size b^k for some integer k.

const SMALL_SUBGROUP_BASE_ADICITY: Option<u32> = None

The integer k such that there exists a multiplicative subgroup of size Self::SMALL_SUBGROUP_BASE^k.

const LARGE_SUBGROUP_ROOT_OF_UNITY: Option<Self::BigInteger> = None

GENERATOR^((MODULUS-1) / (2^s * SMALL_SUBGROUP_BASE^SMALL_SUBGROUP_BASE_ADICITY)) Used for mixed-radix FFT.

Required Associated Types

type BigInteger: BigInteger

Dyn Compatibility

This trait is not dyn compatible.

In older versions of Rust, dyn compatibility was called "object safety", so this trait is not object safe.

Implementors