Struct DecisionVariableAnalysis

pub struct DecisionVariableAnalysis { /* private fields */ }

The result of analyzing the decision variables in an instance.

Responsibility

This struct is responsible for

• Serving kind-based and usage-based partitioning of decision variables to solvers. Solvers only want to know the mathematical properties of the optimization problem. They do not need to know the details of the instance, such as the names of the decision variables and constraints, removed constraints or fixed variables which does not affect the optimization problem itself.

• Validating the state returned by solvers, and populating the variables which does not passed to the solvers.

  • The state by solvers is valid if:
    • It contains every Self::used decision variables. Other IDs are allowed as long as consistent with the population result.
    • The values for each decision variable are within the bounds.
  • Self::populate checks the state is valid, and populates the state as follows:
    • For Self::fixed ID, the fixed value is used.
    • For Self::irrelevant ID, Bound::nearest_to_zero is used as the value.
    • For Self::dependent ID, the value is evaluated from other IDs.

Invariants

• Every IDs are subset of Self::all.
• (kind-based partitioning) Self::binary, Self::integer, Self::continuous, Self::semi_integer, and Self::semi_continuous are disjoint, and their union is equal to Self::all.
• (usage-based partitioning) The union of Self::used_in_objective and Self::used_in_constraints (= Self::used), Self::fixed, and Self::dependent are disjoint each other. Remaining decision variables are Self::irrelevant.

Implementations

impl DecisionVariableAnalysis

pub fn all(&self) -> &VariableIDSet

The IDs of all decision variables

pub fn binary(&self) -> &Bounds

pub fn integer(&self) -> &Bounds

pub fn continuous(&self) -> &Bounds

pub fn semi_integer(&self) -> &Bounds

pub fn semi_continuous(&self) -> &Bounds

pub fn used_in_objective(&self) -> &VariableIDSet

The set of decision variables that are used in the objective function.

pub fn used_in_constraints(&self) -> &BTreeMap<ConstraintID, VariableIDSet>

The set of decision variables that are used in the constraints.

pub fn used(&self) -> &VariableIDSet

The set of decision variables that are used in the objective function or constraints.

pub fn fixed(&self) -> &BTreeMap<VariableID, f64>

Fixed decision variables

pub fn dependent(&self) -> &BTreeMap<VariableID, (Kind, Bound, Function)>

Dependent variables

pub fn irrelevant(&self) -> &BTreeMap<VariableID, (Kind, Bound)>

The set of decision variables that are not used in the objective or constraints and are not fixed or dependent.

impl DecisionVariableAnalysis

pub fn used_binary(&self) -> Bounds

pub fn used_integer(&self) -> Bounds

pub fn used_continuous(&self) -> Bounds

pub fn used_semi_integer(&self) -> Bounds

pub fn used_semi_continuous(&self) -> Bounds

pub fn populate( &self, state: State, atol: ATol, ) -> Result<State, StateValidationError>

Check the state is valid, and populate the state with the removed decision variables

Post-condition

• The IDs of returned State are the same as Self::all.

Trait Implementations

impl AbsDiffEq for DecisionVariableAnalysis

Check if used decision variables has the same bounds

Other decision variables e.g. fixed are ignored.

type Epsilon = ATol

Used for specifying relative comparisons.

fn default_epsilon() -> Self::Epsilon

The default tolerance to use when testing values that are close together.

fn abs_diff_eq(&self, other: &Self, epsilon: Self::Epsilon) -> bool

A test for equality that uses the absolute difference to compute the approximate equality of two numbers.

fn abs_diff_ne(&self, other: &Rhs, epsilon: Self::Epsilon) -> bool

The inverse of [AbsDiffEq::abs_diff_eq].

impl Clone for DecisionVariableAnalysis

fn clone(&self) -> DecisionVariableAnalysis

Returns a copy of the value.

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

Performs copy-assignment from source.

impl Debug for DecisionVariableAnalysis

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

Formats the value using the given formatter.

impl PartialEq for DecisionVariableAnalysis

fn eq(&self, other: &DecisionVariableAnalysis) -> 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 DecisionVariableAnalysis