Struct OnTheFlyTwiddleAccess

pub struct OnTheFlyTwiddleAccess<F, SEvals = Vec<F>> { /* private fields */ }

Twiddle access method that does on-the-fly computation to reduce its memory footprint.

This implementation uses a small amount of precomputed constants from which the twiddle factors are derived on the fly (OTF). The number of constants is ~$1/2 d^2$ field elements for a domain of size $2^d$.

Implementations

impl<F: BinaryField> OnTheFlyTwiddleAccess<F>

pub fn generate<DomainField: BinaryField + Into<F>>( log_domain_size: usize, ) -> Result<Vec<Self>, Error>

Generate a vector of OnTheFlyTwiddleAccess objects, one for each NTT round.

Trait Implementations

impl<F: Debug, SEvals: Debug> Debug for OnTheFlyTwiddleAccess<F, SEvals>

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

Formats the value using the given formatter.

impl<F, SEvals> TwiddleAccess<F> for OnTheFlyTwiddleAccess<F, SEvals>

where F: BinaryField, SEvals: Deref<Target = [F]>,

fn log_n(&self) -> usize

Base-2 logarithm of the number of twiddle factors in this round.

fn get(&self, i: usize) -> F

Get the twiddle factor at the given index.

fn get_pair(&self, index_bits: usize, i: usize) -> (F, F)

Get the pair of twiddle factors at the indices index and (1 << index_bits) | index.

fn coset(&self, coset_bits: usize, coset: usize) -> impl TwiddleAccess<F>

Returns a scoped twiddle access for the coset that fixes the upper coset_bits of the index to coset.