Struct Sobol 

pub struct Sobol {
    pub seed: u64,
}

Cover the space evenly, one binary bisection per knob.

The same promise as Halton — uniform by construction for every prefix — paid for elsewhere: Halton reads knob d in base the d-th prime, so its cover thins as the primes grow, while this reads every knob in base two and separates them with a set of direction numbers each.

Chosen, and that is the price: a Sobol sequence built on the wrong numbers does not fail, it covers worse and nobody finds out. These are Joe and Kuo’s (2008), and a test walks the first dimensions against published values, because reading a table is not a way of checking it. Past KNOBS dimensions ask answers None from the first trial rather than quietly in the middle. Its point is a function of the seed and the index.

Fields

seed: u64

The seed, which here shifts the digits rather than drawing them: without it a Sobol sequence is one fixed sequence and two studies of the same space would walk it in exactly the same order.

Implementations

impl Sobol

pub fn ask( &self, space: &Space, trial: usize, _seen: &[(Point, Option<f64>)], ) -> Option<Point>

The trial-th point, or None when there are more knobs than the table has. It never runs out, and it never looks at what the finished trials did.

Trait Implementations

impl Clone for Sobol

fn clone(&self) -> Sobol

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for Sobol

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

Formats the value using the given formatter.

impl From<Sobol> for Sampler

fn from(how: Sobol) -> Self

Converts to this type from the input type.

impl Hash for Sobol

fn hash<__H: Hasher>(&self, state: &mut __H)

Feeds this value into the given Hasher.

fn hash_slice<H>(data: &[Self], state: &mut H)

where H: Hasher, Self: Sized,

Feeds a slice of this type into the given Hasher.

impl PartialEq for Sobol

fn eq(&self, other: &Sobol) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl Eq for Sobol

impl StructuralPartialEq for Sobol