Package org.tweetyproject.math.opt.problem

Class ConstraintSatisfactionProblem

java.lang.Object

java.util.AbstractCollection<OptProbElement>

java.util.AbstractSet<OptProbElement>

java.util.HashSet<OptProbElement>

org.tweetyproject.math.opt.problem.GeneralConstraintSatisfactionProblem

org.tweetyproject.math.opt.problem.ConstraintSatisfactionProblem

All Implemented Interfaces:

Serializable, Cloneable, Iterable<OptProbElement>, Collection<OptProbElement>, Set<OptProbElement>

Direct Known Subclasses:

OptimizationProblem

public class ConstraintSatisfactionProblem
extends GeneralConstraintSatisfactionProblem

This class models a general constraint satisfaction problem.

Author:

Matthias Thimm

See Also:

• Serialized Form

Constructor Summary

Constructors

Constructor	Description
ConstraintSatisfactionProblem()	Creates a new and empty csp.
ConstraintSatisfactionProblem(Collection<? extends Statement> statements)	Creates a new csp with the given statements

Method Summary

Modifier and Type	Method	Description
ConstraintSatisfactionProblem	clone()
void	collapseAssociativeOperations()	This method collapses all associative operations appearing in the target function and the constraints, e.g.
Set<Minimum>	getMinimums()	Returns all minimums appearing in this problem.
Set<Variable>	getVariables()	Returns all variables of this problem.
boolean	isInteger()	Checks whether this problem is integer, i.e.
boolean	isLinear()	Checks whether every constraint of this problem is linear.
boolean	isMinimumFree()	Checks whether this problem uses no minimum function.
void	resolveMaximums()	Resolves all occurrences of maximums by substituting a maximum "max{a,b}" by "0.5 a + 0.5 b + abs(a-b)".
void	resolveMinimums()	Resolves all occurrences of minimums by substituting a minimum "min{a,b}" by "0.5 a + 0.5 b - abs(a-b)".
ConstraintSatisfactionProblem	toNormalizedForm()	Normalizes this problem, i.e.
String	toString()

Methods inherited from class java.util.HashSet

add, clear, contains, isEmpty, iterator, newHashSet, remove, size, spliterator, toArray, toArray

Methods inherited from class java.util.AbstractSet

equals, hashCode, removeAll

Methods inherited from class java.util.AbstractCollection

addAll, containsAll, retainAll

Methods inherited from class java.lang.Object

getClass, notify, notifyAll, wait, wait, wait

Methods inherited from interface java.util.Collection

parallelStream, removeIf, stream, toArray

Methods inherited from interface java.lang.Iterable

forEach

Methods inherited from interface java.util.Set

addAll, containsAll, equals, hashCode, removeAll, retainAll

Constructor Details

ConstraintSatisfactionProblem

public ConstraintSatisfactionProblem()

Creates a new and empty csp.

ConstraintSatisfactionProblem

public ConstraintSatisfactionProblem(Collection<? extends Statement> statements)

Creates a new csp with the given statements

Parameters:

statements - a collection of statements.

Method Details

toNormalizedForm

public ConstraintSatisfactionProblem toNormalizedForm()

Normalizes this problem, i.e. every constraint is brought into an equivalent form "T> 0" or "T >= 0" or "T = 0" or "T != 0".

Returns:

a csp.

isLinear

public boolean isLinear()

Checks whether every constraint of this problem is linear.

Returns:

"true" if every constraint of this problem is linear.

isInteger

public boolean isInteger()

Checks whether this problem is integer, i.e. whether all variables are integer variables.

Returns:

"true" if this problem is integer.

isMinimumFree

public boolean isMinimumFree()

Checks whether this problem uses no minimum function.

Returns:

"true" if this problem uses no minimum function.

resolveMinimums

public void resolveMinimums()

Resolves all occurrences of minimums by substituting a minimum "min{a,b}" by "0.5 a + 0.5 b - abs(a-b)".

resolveMaximums

public void resolveMaximums()

Resolves all occurrences of maximums by substituting a maximum "max{a,b}" by "0.5 a + 0.5 b + abs(a-b)".

getVariables

public Set<Variable> getVariables()

Returns all variables of this problem.

Returns:

all variables of this problem.

getMinimums

public Set<Minimum> getMinimums()

Returns all minimums appearing in this problem.

Returns:

all minimums appearing in this problem.

collapseAssociativeOperations

public void collapseAssociativeOperations()

This method collapses all associative operations appearing in the target function and the constraints, e.g. every min{min{a,b},c} becomes min{a,b,c}

toString

public String toString()

Overrides:

toString in class AbstractCollection<OptProbElement>

clone

public ConstraintSatisfactionProblem clone()

Overrides:

clone in class HashSet<OptProbElement>