Struct AliasTable 

pub struct AliasTable { /* private fields */ }

Walker/Vose alias table over a discrete PDF.

Build once with AliasTable::new, then draw with AliasTable::sample using two uniform random numbers in [0, 1).

Implementations

impl AliasTable

pub fn new(pdf: &[f64]) -> Result<Self, Error>

Build an alias table from a non-negative PDF.

The PDF is normalized internally so the standalone API is safe with unnormalized input (the underlying construction assumes a unit sum).

pub fn sample(&self, r1: f64, r2: f64) -> usize

Draw one index using two uniforms in [0, 1).

Mirrors sample_pdf(rand1, rand2): pick column n * rand1, return it when rand2 < prob[column], else the column’s alias.

r1 is saturated to [0, n) before indexing: negative values map to column 0 and values >= 1.0 map to column n - 1. This is intentional defensive behavior; callers should still pass uniforms in [0, 1).

pub fn pdf(&self) -> &[f64]

The normalized PDF the table samples from.

pub fn len(&self) -> usize

Number of bins.

pub fn is_empty(&self) -> bool

Whether the table has no bins.

Trait Implementations

impl Clone for AliasTable

fn clone(&self) -> AliasTable

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for AliasTable

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

Formats the value using the given formatter.

impl PartialEq for AliasTable

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

Equality operator ==.

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

Inequality operator !=.

impl StructuralPartialEq for AliasTable