Module com.darkcollective.relix.solver

Package com.darkcollective.relix.solver

Record Class LinearProgram

java.lang.Object

java.lang.Record

com.darkcollective.relix.solver.LinearProgram

Record Components:

sense - whether the objective is maximised or minimised

variables - the decision variables, in the order a solution reports them

constraints - the linear constraints; may be empty

public record LinearProgram(LinearProgram.Sense sense, List<LinearProgram.Variable> variables, List<LinearProgram.Constraint> constraints)
extends Record

One linear program: an objective to maximise or minimise over a list of decision variables, subject to a list of linear constraints over the same variables.

This is the whole of what the engine says to a solver. Every relational notion — which rows are candidates, what expression produced a coefficient, what a NULL coefficient means — has already been resolved by the time a program is built; what remains is arithmetic. That split is deliberate: the rules for dropping a row whose objective is NULL are the OPTIMIZE operator's semantics, and two solvers must not be able to disagree about them.

A constraint's coefficient array is positional: coefficients[i] multiplies variables.get(i), and the array is exactly as long as the variable list.

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static final record	LinearProgram.Constraint	One linear constraint: Σ coefficients[i]·x[i] related to bound.
static enum	LinearProgram.Relation	How a constraint's weighted sum relates to its bound.
static enum	LinearProgram.Sense	Whether the objective is to be maximised or minimised.
static final record	LinearProgram.Variable	One decision variable: a value in [lower, upper] contributing weight per unit to the objective.

Constructor Summary

Constructors

Constructor	Description
LinearProgram(LinearProgram.Sense sense, List<LinearProgram.Variable> variables, List<LinearProgram.Constraint> constraints)	Creates an instance of a LinearProgram record class.

Method Summary

Modifier and Type	Method	Description
List<LinearProgram.Constraint>	constraints()	Returns the value of the constraints record component.
final boolean	equals(Object o)	Indicates whether some other object is "equal to" this one.
final int	hashCode()	Returns a hash code value for this object.
LinearProgram.Sense	sense()	Returns the value of the sense record component.
final String	toString()	Returns a string representation of this record class.
List<LinearProgram.Variable>	variables()	Returns the value of the variables record component.

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Constructor Details

LinearProgram

public LinearProgram(LinearProgram.Sense sense,
 List<LinearProgram.Variable> variables,
 List<LinearProgram.Constraint> constraints)

Creates an instance of a LinearProgram record class.

Parameters:

sense - the value for the sense record component

variables - the value for the variables record component

constraints - the value for the constraints record component

Method Details

toString

public final String toString()

Returns a string representation of this record class. The representation contains the name of the class, followed by the name and value of each of the record components.

Specified by:

toString in class Record

Returns:

a string representation of this object

hashCode

public final int hashCode()

Returns a hash code value for this object. The value is derived from the hash code of each of the record components.

Specified by:

hashCode in class Record

Returns:

a hash code value for this object

equals

public final boolean equals(Object o)

Indicates whether some other object is "equal to" this one. The objects are equal if the other object is of the same class and if all the record components are equal. All components in this record class are compared with Objects::equals(Object,Object).

Specified by:

equals in class Record

Parameters:

o - the object with which to compare

Returns:

true if this object is the same as the o argument; false otherwise.

sense

public LinearProgram.Sense sense()

Returns the value of the sense record component.

Returns:

the value of the sense record component

variables

public List<LinearProgram.Variable> variables()

Returns the value of the variables record component.

Returns:

the value of the variables record component

constraints

public List<LinearProgram.Constraint> constraints()

Returns the value of the constraints record component.

Returns:

the value of the constraints record component