Module ojalgo

Package org.ojalgo.optimisation

Interface ExpressionsBasedModel.EntityMap

All Superinterfaces:

Optimisation, Optimisation.ProblemStructure

All Known Implementing Classes:

ConvexData, LinearStructure

Enclosing class:

ExpressionsBasedModel

public static interface ExpressionsBasedModel.EntityMap
extends Optimisation.ProblemStructure

Connects solver constraints and variables back to model entities. Used for 2 things:

1. Solvers that manipulate models (like the IntegerSolver) need this to map between model entities and solver indices.
2. Simplifies implementation of ExpressionsBasedModel.Integration.toModelState(org.ojalgo.optimisation.Optimisation.Result, ExpressionsBasedModel).

Nested Class Summary

Nested classes/interfaces inherited from interface org.ojalgo.optimisation.Optimisation

Optimisation.Constraint, Optimisation.ConstraintType, Optimisation.Integration<M extends Optimisation.Model,S extends Optimisation.Solver>, Optimisation.Model, Optimisation.Objective, Optimisation.Options, Optimisation.ProblemStructure, Optimisation.Result, Optimisation.Sense, Optimisation.Solver, Optimisation.State

Field Summary

Fields inherited from interface org.ojalgo.optimisation.Optimisation.ProblemStructure

DEBUG

Method Summary

Modifier and Type	Method	Description
int	countModelVariables()	The number of variables, in the solver, that directly correspond to a model variable.
int	countSlackVariables()	The number of slack variables.
EntryPair<ModelEntity<?>,Optimisation.ConstraintType>	getConstraint(int idc)
EntryPair<ModelEntity<?>,Optimisation.ConstraintType>	getSlack(int ids)	Returns which model entity, and constraint type, that corresponds to the slack variable at the supplied index.
int	indexOf(int idm)	Converts from a solver specific variable index to the corresponding index of the variable in the model.
boolean	isNegated(int idm)	Is this solver variable negated relative to the corresponding model variable?

Methods inherited from interface org.ojalgo.optimisation.Optimisation.ProblemStructure

countAdditionalConstraints, countConstraints, countEqualityConstraints, countInequalityConstraints, countVariables

Method Details

countModelVariables

int countModelVariables()

The number of variables, in the solver, that directly correspond to a model variable. (Not slack or artificial variables.)

This defines the range of the indices that can be used with the indexOf(int) and isNegated(int) methods.

countSlackVariables

int countSlackVariables()

The number of slack variables.

This defines the range of the indices that can be used with the getSlack(int) method.

getConstraint

EntryPair<ModelEntity<?>,Optimisation.ConstraintType> getConstraint(int idc)

getSlack

EntryPair<ModelEntity<?>,Optimisation.ConstraintType> getSlack(int ids)

Returns which model entity, and constraint type, that corresponds to the slack variable at the supplied index.

Parameters:

ids - Index of solver slack variable (If there are 3 slack variables this input argument should be in the range [0.2].)

indexOf

int indexOf(int idm)

Converts from a solver specific variable index to the corresponding index of the variable in the model. Note that not all model variables are necessarily represented in the solver, and a model variable may result in multiple solver variables. Further, slack variables, artificial variables and such are typically not represented in the model.

Parameters:

idm - Index of solver variable

Returns:

Index of model variable (negative if no map)

isNegated

boolean isNegated(int idm)

Is this solver variable negated relative to the corresponding model variable?

Parameters:

idm - Index of solver variable

Returns:

true if this solver variable represents a negated model variable