Struct Variable 

pub struct Variable { /* private fields */ }

A number the optimizer may change: its name, where it starts, the size of its first steps, the range it must stay in, and whether it takes only whole numbers. It serializes as its fields (an unbounded side as null; integer only when true, and read as false when absent), and reads back through Variable::new, Variable::within and Variable::integer’s checks.

Implementations

impl Variable

pub fn new( name: impl Into<String>, start: f64, step: f64, ) -> Result<Self, AnalysisError>

A variable named name, starting at start, with no bounds. step is the size of the optimizer’s first steps in it: about a quarter to a third of the range its best value is expected in, in the variable’s own units.

Errors

AnalysisError::Domain for a start that isn’t finite, or a step that isn’t finite and positive.

pub fn within(self, low: f64, high: f64) -> Result<Self, AnalysisError>

The same variable, held to [low, high]. Either bound may be infinite, for none.

Errors

AnalysisError::Domain for a NaN bound, a high not above low, a start outside the range, or for an integer variable bounds that aren’t whole numbers within ±2⁵².

pub fn integer(self) -> Result<Self, AnalysisError>

The same variable, taking only the whole numbers from its low bound to its high one: a count, or the place of a choice in a list (a motor, a catalog part). The optimizer still draws it as a real number, and the model is given the whole number nearest the draw, clamped to the bounds (Variable::encode); cmaes keeps every value within reach by the margin of CMA-ES with margin. Its step is the size of the first steps, in whole numbers: 1 is a good start for a handful of choices. Its start may lie between two whole numbers, as the draws are centered on it.

Errors

AnalysisError::Domain for bounds that aren’t whole numbers within ±2⁵²: set them first with Variable::within, which checks them again if called after.

pub fn is_integer(&self) -> bool

Whether it takes only whole numbers (Variable::integer).

pub fn encode(&self, x: f64) -> f64

The value the model is given for a draw x: x itself, or for an integer variable the whole number nearest x, a draw halfway between two going to the lower, clamped to the bounds. These are the encoding of R. Hamano et al., “CMA-ES with Margin”, GECCO 2022 (arXiv:2205.13482, §4.1, p. 5), with thresholds halfway between neighbouring values. NaN stays NaN (a run stops before it would draw one).

pub fn name(&self) -> &str

Its name.

pub fn start(&self) -> f64

Where it starts.

pub fn step(&self) -> f64

The size of its first steps.

pub fn low(&self) -> f64

Its low bound, −∞ for none.

pub fn high(&self) -> f64

Its high bound, +∞ for none.

pub fn contains(&self, x: f64) -> bool

Whether x is within its bounds.

Trait Implementations

impl Clone for Variable

fn clone(&self) -> Variable

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for Variable

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

Formats the value using the given formatter.

impl<'de> Deserialize<'de> for Variable

fn deserialize<__D>(__deserializer: __D) -> Result<Self, __D::Error>

where __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl PartialEq for Variable

fn eq(&self, other: &Variable) -> 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 Serialize for Variable

fn serialize<__S>(&self, __serializer: __S) -> Result<__S::Ok, __S::Error>

where __S: Serializer,

Serialize this value into the given Serde serializer.

impl StructuralPartialEq for Variable