Struct Factor 

pub struct Factor {
    pub id: String,
    pub variables: Vec<String>,
    pub values: Vec<f64>,
    pub shape: Vec<usize>,
}

A factor (un-normalised joint distribution table) over a set of variables.

values is stored in row-major order: the last variable in variables varies fastest. shape[i] is the cardinality of variables[i].

Fields

id: String

Human-readable label.

variables: Vec<String>

Ordered variable scope.

values: Vec<f64>

Flat probability/potential table.

shape: Vec<usize>

Shape array — shape[i] is the number of states for variables[i].

Implementations

impl Factor

pub fn product(&self, other: &Factor) -> Factor

Compute the factor product of self and other.

The result has the union of both variable scopes. Values are the point-wise product over all joint assignments.

pub fn marginalize( &self, variable: &str, _var_map: &HashMap<String, usize>, ) -> Factor

Marginalize variable out of this factor by summing over all its states.

var_map maps variable names to their cardinalities and is used for consistency checking; the actual cardinality is taken from self.shape.

pub fn reduce( &self, variable: &str, state: usize, _var_map: &HashMap<String, usize>, ) -> Factor

Reduce this factor by fixing variable to state (slice operation).

The resulting factor no longer contains variable in its scope.

pub fn normalize(&mut self)

Normalize: divide all values by their sum so they sum to 1.

pub fn contains_variable(&self, variable: &str) -> bool

Whether variable appears in this factor’s scope.

pub fn entropy(&self) -> f64

Compute the entropy of this factor’s values (assumes they are normalised probabilities). Returns H = -Σ p log₂ p.

Trait Implementations

impl Clone for Factor

fn clone(&self) -> Factor

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for Factor

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

Formats the value using the given formatter.

impl PartialEq for Factor

fn eq(&self, other: &Factor) -> 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 StructuralPartialEq for Factor