Module org.chocosolver.solver

Package org.chocosolver.solver

Class Model

java.lang.Object

org.chocosolver.solver.Model

All Implemented Interfaces:

IConstraintFactory, IDecompositionFactory, IIntConstraintFactory, IRealConstraintFactory, IReificationFactory, ISatFactory, ISetConstraintFactory, IModel, ISelf<Model>, IVariableFactory, IViewFactory

public class Model
extends Object
implements IModel

The Model is the header component of Constraint Programming. It embeds the list of Variable (and their Domain), the Constraint's network, and a IPropagationEngine to pilot the propagation.
Model includes a AbstractSearchLoop to guide the search loop: applying decisions and propagating, running backups and rollbacks and storing solutions.

Since:

0.01

Version:

0.01, june 2010

Author:

Xavier Lorca, Charles Prud'homme, Jean-Guillaume Fages, Arnaud Malapert

See Also:

Variable, Constraint

Field Summary

Fields

Modifier and Type	Field	Description
static String	CLAUSES_HOOK_NAME
static String	CLAUSESBUILDER_HOOK_NAME
static String	IBEX_HOOK_NAME
static boolean	MAXIMIZE
static boolean	MINIMIZE
static String	MINISAT_HOOK_NAME
static String	NOGOODS_HOOK_NAME
static String	TASK_SET_HOOK_NAME	Name of internal hook dedicated to store declared Task.

Fields inherited from interface org.chocosolver.solver.variables.IVariableFactory

CSTE_NAME

Constructor Summary

Constructors

Constructor	Description
Model()	Creates a Model object to formulate a decision problem by declaring variables and posting constraints.
Model(String name)	Creates a Model object to formulate a decision problem by declaring variables and posting constraints.
Model(String name, Settings settings)	Creates a Model object to formulate a decision problem by declaring variables and posting constraints.
Model(IEnvironment environment, String name)	Creates a Model object to formulate a decision problem by declaring variables and posting constraints.
Model(IEnvironment environment, String name, Settings settings)	Creates a Model object to formulate a decision problem by declaring variables and posting constraints.
Model(Settings settings)	Creates a Model object to formulate a decision problem by declaring variables and posting constraints.

Method Summary

Modifier and Type	Method	Description
void	addHook(String hookName, Object hookObject)	Adds the hookObject to store in this model, associated with the name hookName.
void	associates(Variable variable)	Link a variable to this.
void	clearObjective()	Removes any objective and set problem to a satisfaction problem
Constraint	falseConstraint()	The basic "false" constraint, which is always violated
gnu.trove.map.hash.TIntObjectHashMap<IntVar>	getCachedConstants()	Get the map of constant IntVar the have default names to avoid creating multiple identical constants.
ClauseBuilder	getClauseBuilder()
ClauseConstraint	getClauseConstraint()	Return a constraint embedding a signed-clauses store.
long	getCreationTime()	Get the creation time (in milliseconds) of the model (to estimate modeling duration)
Constraint[]	getCstrs()	Returns the array of Constraint objects posted in this Model.
IEnvironment	getEnvironment()	Return the backtracking environment of this model.
Object	getHook(String hookName)	Returns the object associated with the named hookName
protected Map<String,Object>	getHooks()	Returns the map containing declared hooks.
IbexHandler	getIbexHandler()	Return a constraint embedding an instance of Ibex (continuous solver).
SatConstraint	getMinisat()	Returns the unique constraint embedding a minisat model.
String	getName()	Return the name of this model.
int	getNbBoolVar()	Returns the number of BoolVar of the model involved in this, It also counts FIXED variables and VIEWS, if any.
int	getNbCstrs()	Return the number of constraints posted in this.
int	getNbIntVar(boolean includeBoolVar)	Returns the number of IntVar of the model involved in this, excluding BoolVar if includeBoolVar=false.
int	getNbRealVar()	Returns the number of RealVar of the model involved in this, It also counts FIXED variables and VIEWS, if any.
int	getNbSetVar()	Returns the number of SetVar of the model involved in this, It also counts FIXED variables and VIEWS, if any.
int	getNbVars()	Returns the number of variables involved in this.
NogoodConstraint	getNogoodStore()	Return a constraint embedding a nogood store (based on a sat model).
Variable	getObjective()	Return the (possibly null) objective variable
double	getPrecision()	In case of real variable(s) to optimize, a precision is required.
ResolutionPolicy	getResolutionPolicy()	Get the resolution policy of the model
long	getSeed()	Gets the seed used random number generator.
Settings	getSettings()	Return the current settings for the solver
Solver	getSolver()	Returns the unique and internal propagation and search object to solve this model.
Variable	getVar(int i)	Returns the ith variable within the array of variables defined in this.
Variable[]	getVars()	Returns the array of Variable objects declared in this Model.
int	nextId()	Get a free single-use id to identify a new variable.
int	nextNameId()	Get a free single-use name id to identify a variable created internally.
void	post(Constraint... cs)	Posts constraints cs permanently in the constraints network of this: - add them to the data structure, - set the fixed idx, - checks for restrictions
void	postTemp(Constraint... cs)	Posts constraints cs temporary, that is, they will be unposted upon backtrack.
Model	ref()
void	removeAllHooks()	Empties the hooks attached to this model.
void	removeHook(String hookName)	Removes the hook named hookName
void	removeMinisat()	Unpost minisat constraint from model, if any.
void	removeNogoodStore()	Unpost nogood store constraint from model, if any.
BoolVar[]	retrieveBoolVars()	Iterate over the variable of this and build an array that contains the BoolVar only.
IntVar[]	retrieveIntVars(boolean includeBoolVar)	Iterate over the variable of this and build an array that contains all the IntVar of the model.
RealVar[]	retrieveRealVars()	Iterate over the variable of this and build an array that contains the RealVar only.
SetVar[]	retrieveSetVars()	Iterate over the variable of this and build an array that contains the SetVar only.
void	setName(String name)	Changes the name of this model to be equal to the argument name.
void	setObjective(boolean maximize, Variable objective)	Defines the variable to optimize (maximize or minimize) By default, each solution forces either : for MAXIMIZE: to increase by one IntVar (or precision for RealVar) the objective lower bound, or for MINIMIZE: to decrease by one IntVar (or precision for RealVar) the objective upper bound.
void	setPrecision(double p)	In case of real variable to optimize, a precision is required.
void	setSeed(long seed)	Sets the seed used for random number generator using a single long seed.
String	toString()	Return a string describing the CSP defined in this model.
Constraint	trueConstraint()	The basic "true" constraint, which is always satisfied
void	unassociates(Variable variable)	Unlink the variable from this.
void	unpost(Constraint... constraints)	Remove permanently the constraint c from the constraint network.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Methods inherited from interface org.chocosolver.solver.constraints.IDecompositionFactory

binPackingDec, cumulativeTimeDec, element, element, regularDec

Methods inherited from interface org.chocosolver.solver.constraints.IIntConstraintFactory

absolute, allDifferent, allDifferent, allDifferentExcept0, allDifferentUnderCondition, allEqual, among, and, and, arithm, arithm, arithm, arithm, atLeastNValues, atMostNValues, binPacking, bitsIntChanneling, boolsIntChanneling, circuit, circuit, circuit, clausesIntChanneling, costRegular, count, count, cumulative, cumulative, cumulative, cumulative, cumulative, diffN, distance, distance, div, element, element, element, getDomainUnion, globalCardinality, intValuePrecedeChain, intValuePrecedeChain, inverseChanneling, inverseChanneling, keySort, knapsack, lexChainLess, lexChainLessEq, lexLess, lexLessEq, max, max, max, mddc, member, member, member, min, min, min, mod, mod, mod, multiCostRegular, multiCostRegular, not, notAllEqual, notMember, notMember, notMember, nValues, or, or, path, path, regular, scalar, scalar, scalar, scalar, sort, square, subCircuit, subPath, sum, sum, sum, sum, sum, sum, sum, table, table, table, table, times, times, times, tree, tree

Methods inherited from interface org.chocosolver.solver.constraints.IRealConstraintFactory

element, eq, ibex, realIbexGenericConstraint, scalar

Methods inherited from interface org.chocosolver.solver.constraints.IReificationFactory

ifOnlyIf, ifThen, ifThen, ifThenElse, ifThenElse, reification, reifyXeqC, reifyXeqY, reifyXeqYC, reifyXgeY, reifyXgtC, reifyXgtY, reifyXgtYC, reifyXinS, reifyXleY, reifyXltC, reifyXltY, reifyXltYC, reifyXneC, reifyXneY, reifyXneYC, reifyXnotinS

Methods inherited from interface org.chocosolver.solver.constraints.ISatFactory

addClauseFalse, addClauses, addClauses, addClausesAtMostNMinusOne, addClausesAtMostOne, addClausesBoolAndArrayEqualFalse, addClausesBoolAndArrayEqVar, addClausesBoolAndEqVar, addClausesBoolEq, addClausesBoolIsEqVar, addClausesBoolIsLeVar, addClausesBoolIsLtVar, addClausesBoolIsNeqVar, addClausesBoolLe, addClausesBoolLt, addClausesBoolNot, addClausesBoolOrArrayEqualTrue, addClausesBoolOrArrayEqVar, addClausesBoolOrEqVar, addClausesBoolXorEqVar, addClausesMaxBoolArrayLessEqVar, addClausesSumBoolArrayGreaterEqVar, addClausesSumBoolArrayLessEqVar, addClauseTrue, addConstructiveDisjunction

Methods inherited from interface org.chocosolver.solver.constraints.ISetConstraintFactory

allDifferent, allDisjoint, allEqual, disjoint, element, element, intersection, intersection, inverseSet, max, max, member, member, member, min, min, nbEmpty, nbEmpty, notEmpty, notMember, notMember, offSet, partition, setBoolsChanneling, setBoolsChanneling, setsIntsChanneling, setsIntsChanneling, subsetEq, sum, sumElements, sumElements, symmetric, symmetric, union, union

Methods inherited from interface org.chocosolver.solver.variables.IVariableFactory

boolVar, boolVar, boolVar, boolVar, boolVarArray, boolVarArray, boolVarMatrix, boolVarMatrix, checkIntDomainRange, checkRealDomainRange, generateName, generateName, intVar, intVar, intVar, intVar, intVar, intVar, intVar, intVar, intVarArray, intVarArray, intVarArray, intVarArray, intVarArray, intVarArray, intVarMatrix, intVarMatrix, intVarMatrix, intVarMatrix, intVarMatrix, intVarMatrix, realVar, realVar, realVar, realVar, realVar, realVarArray, realVarArray, realVarMatrix, realVarMatrix, setVar, setVar, setVar, setVar, setVarArray, setVarArray, setVarMatrix, setVarMatrix, taskVar, taskVar, taskVar, taskVar, taskVarArray, taskVarMatrix, toBoolVar

Methods inherited from interface org.chocosolver.solver.variables.IViewFactory

boolNotView, intAbsView, intAffineView, intEqView, intGeView, intLeView, intMinusView, intNeView, intOffsetView, intScaleView, realIntView, realIntViewArray, realIntViewMatrix

Field Detail

MAXIMIZE

public static boolean MAXIMIZE

MINIMIZE

public static boolean MINIMIZE

TASK_SET_HOOK_NAME

public static final String TASK_SET_HOOK_NAME

Name of internal hook dedicated to store declared Task.

See Also:

Constant Field Values

MINISAT_HOOK_NAME

public static final String MINISAT_HOOK_NAME

See Also:

Constant Field Values

NOGOODS_HOOK_NAME

public static final String NOGOODS_HOOK_NAME

See Also:

Constant Field Values

CLAUSES_HOOK_NAME

public static final String CLAUSES_HOOK_NAME

See Also:

Constant Field Values

CLAUSESBUILDER_HOOK_NAME

public static final String CLAUSESBUILDER_HOOK_NAME

See Also:

Constant Field Values

IBEX_HOOK_NAME

public static final String IBEX_HOOK_NAME

See Also:

Constant Field Values

Constructor Detail

Model

public Model(IEnvironment environment,
             String name,
             Settings settings)

Creates a Model object to formulate a decision problem by declaring variables and posting constraints. The model is named name and it uses a specific backtracking environment.

Parameters:

environment - a backtracking environment to allow search

name - The name of the model (for logging purpose)

settings - settings to use

Model

public Model(IEnvironment environment,
             String name)

Creates a Model object to formulate a decision problem by declaring variables and posting constraints. The model is named name and it uses a specific backtracking environment.

Parameters:

environment - a backtracking environment to allow search

name - The name of the model (for logging purpose)

Model

public Model(String name,
             Settings settings)

Creates a Model object to formulate a decision problem by declaring variables and posting constraints. The model is named name and it uses a specific backtracking environment.

Parameters:

name - The name of the model (for logging purpose)

settings - settings to use

Model

public Model(String name)

Creates a Model object to formulate a decision problem by declaring variables and posting constraints. The model is named name and uses the default (trailing) backtracking environment.

Parameters:

name - The name of the model (for logging purpose)

See Also:

Model(org.chocosolver.memory.IEnvironment, String, Settings)

Model

public Model(Settings settings)

Creates a Model object to formulate a decision problem by declaring variables and posting constraints. The model is uses the default (trailing) backtracking environment.

Parameters:

settings - settings to use

See Also:

Model(org.chocosolver.memory.IEnvironment, String, Settings)

Model

public Model()

Creates a Model object to formulate a decision problem by declaring variables and posting constraints. The model uses the default (trailing) backtracking environment.

See Also:

Model(String)

Method Detail

getCreationTime

public long getCreationTime()

Get the creation time (in milliseconds) of the model (to estimate modeling duration)

Returns:

the time (in ms) of the creation of the model

getResolutionPolicy

public ResolutionPolicy getResolutionPolicy()

Get the resolution policy of the model

Returns:

the resolution policy of the model

See Also:

ResolutionPolicy

getCachedConstants

public gnu.trove.map.hash.TIntObjectHashMap<IntVar> getCachedConstants()

Get the map of constant IntVar the have default names to avoid creating multiple identical constants. Should not be called by the user.

Returns:

the map of constant IntVar having default names.

trueConstraint

public Constraint trueConstraint()

The basic "true" constraint, which is always satisfied

Returns:

a "true" constraint

falseConstraint

public Constraint falseConstraint()

The basic "false" constraint, which is always violated

Returns:

a "false" constraint

getSolver

public Solver getSolver()

Returns the unique and internal propagation and search object to solve this model.

Returns:

the unique and internal Resolver object.

getVars

public Variable[] getVars()

Returns the array of Variable objects declared in this Model.

Returns:

array of all variables in this model

getNbVars

public int getNbVars()

Returns the number of variables involved in this.

Returns:

number of variables in this model

getVar

public Variable getVar(int i)

Returns the i^th variable within the array of variables defined in this.

Parameters:

i - index of the variable to return.

Returns:

the i^th variable of this model

getNbIntVar

public int getNbIntVar(boolean includeBoolVar)

Returns the number of IntVar of the model involved in this, excluding BoolVar if includeBoolVar=false. It also counts FIXED variables and VIEWS, if any.

Parameters:

includeBoolVar - indicates whether or not to include BoolVar

Returns:

the number of IntVar of the model involved in this

retrieveIntVars

public IntVar[] retrieveIntVars(boolean includeBoolVar)

Iterate over the variable of this and build an array that contains all the IntVar of the model. excludes BoolVar if includeBoolVar=false. It also contains FIXED variables and VIEWS, if any.

Parameters:

includeBoolVar - indicates whether or not to include BoolVar

Returns:

array of IntVar in this model

getNbBoolVar

public int getNbBoolVar()

Returns the number of BoolVar of the model involved in this, It also counts FIXED variables and VIEWS, if any.

Returns:

the number of BoolVar of the model involved in this

retrieveBoolVars

public BoolVar[] retrieveBoolVars()

Iterate over the variable of this and build an array that contains the BoolVar only. It also contains FIXED variables and VIEWS, if any.

Returns:

array of BoolVar in this model

getNbSetVar

public int getNbSetVar()

Returns the number of SetVar of the model involved in this, It also counts FIXED variables and VIEWS, if any.

Returns:

the number of SetVar of the model involved in this

retrieveSetVars

public SetVar[] retrieveSetVars()

Iterate over the variable of this and build an array that contains the SetVar only. It also contains FIXED variables and VIEWS, if any.

Returns:

array of SetVars in this model

getNbRealVar

public int getNbRealVar()

Returns the number of RealVar of the model involved in this, It also counts FIXED variables and VIEWS, if any.

Returns:

the number of RealVar of the model involved in this

retrieveRealVars

public RealVar[] retrieveRealVars()

Iterate over the variable of this and build an array that contains the RealVar only. It also contains FIXED variables and VIEWS, if any.

Returns:

array of RealVar in this model

getCstrs

public Constraint[] getCstrs()

Returns the array of Constraint objects posted in this Model.

Returns:

array of posted constraints

getNbCstrs

public int getNbCstrs()

Return the number of constraints posted in this.

Returns:

number of posted constraints.

getName

public String getName()

Return the name of this model.

Returns:

this model's name

getEnvironment

public IEnvironment getEnvironment()

Return the backtracking environment of this model.

Returns:

the backtracking environment of this model

getObjective

public Variable getObjective()

Return the (possibly null) objective variable

Returns:

a variable (null for satisfaction problems)

getPrecision

public double getPrecision()

In case of real variable(s) to optimize, a precision is required.

Returns:

the precision used

getHook

public Object getHook(String hookName)

Returns the object associated with the named hookName

Parameters:

hookName - the name of the hook to return

Returns:

the object associated to the name hookName

getHooks

protected Map<String,Object> getHooks()

Returns the map containing declared hooks. This map is mutable.

Returns:

the map of hooks.

getMinisat

public SatConstraint getMinisat()

Returns the unique constraint embedding a minisat model. A call to this method will create and post the constraint if it does not exist already.

Returns:

the minisat constraint

removeMinisat

public void removeMinisat()

Unpost minisat constraint from model, if any.

getNogoodStore

public NogoodConstraint getNogoodStore()

Return a constraint embedding a nogood store (based on a sat model). A call to this method will create and post the constraint if it does not exist already.

Returns:

the no good constraint

removeNogoodStore

public void removeNogoodStore()

Unpost nogood store constraint from model, if any.

getClauseConstraint

public ClauseConstraint getClauseConstraint()

Return a constraint embedding a signed-clauses store. A call to this method will create and post the constraint if it does not exist already.

Returns:

the signed-clauses store constraint

getClauseBuilder

public ClauseBuilder getClauseBuilder()

Returns:

an instance of ClauseBuilder that helps creating clause during resolution.

getIbexHandler

public IbexHandler getIbexHandler()

Return a constraint embedding an instance of Ibex (continuous solver). A call to this method will create and post the constraint if it does not exist already.

Returns:

the Ibex constraint

getSettings

public Settings getSettings()

Return the current settings for the solver

Returns:

a Settings

setObjective

public void setObjective(boolean maximize,
                         Variable objective)

Defines the variable to optimize (maximize or minimize) By default, each solution forces either :

• for MAXIMIZE: to increase by one IntVar (or precision for RealVar) the objective lower bound, or
• for MINIMIZE: to decrease by one IntVar (or precision for RealVar) the objective upper bound.

Parameters:

maximize - whether to maximize (true) or minimize (false) the objective

objective - variable to optimize

See Also:

IObjectiveManager.setStrictDynamicCut(), IObjectiveManager.setWalkingDynamicCut(), IObjectiveManager.setCutComputer(Function)

clearObjective

public void clearObjective()

Removes any objective and set problem to a satisfaction problem

setPrecision

public void setPrecision(double p)

In case of real variable to optimize, a precision is required.

Parameters:

p - the precision (default is 0.0001D)

setSeed

public void setSeed(long seed)

Sets the seed used for random number generator using a single long seed.

Parameters:

seed - the initial seed

See Also:

Random.setSeed(long)

getSeed

public long getSeed()

Gets the seed used random number generator.

Returns:

the seed

addHook

public void addHook(String hookName,
                    Object hookObject)

Adds the hookObject to store in this model, associated with the name hookName. A hook is a simple map "hookName" <-> hookObject.

Parameters:

hookName - name of the hook

hookObject - hook to store

removeHook

public void removeHook(String hookName)

Removes the hook named hookName

Parameters:

hookName - name of the hookObject to remove

removeAllHooks

public void removeAllHooks()

Empties the hooks attached to this model.

setName

public void setName(String name)

Changes the name of this model to be equal to the argument name.

Parameters:

name - the new name of this model.

associates

public void associates(Variable variable)

Link a variable to this. This is executed AUTOMATICALLY in variable constructor, so no checked are done on multiple occurrences of the very same variable. Should not be called by the user.

Parameters:

variable - a newly created variable, not already added

unassociates

public void unassociates(Variable variable)

Unlink the variable from this. Should not be called by the user.

Parameters:

variable - variable to un-associate

nextId

public int nextId()

Get a free single-use id to identify a new variable. Should not be called by the user.

Returns:

a free id to use

nextNameId

public int nextNameId()

Get a free single-use name id to identify a variable created internally. Should not be called by the user.

Returns:

a free id to use

post

public void post(Constraint... cs)
          throws SolverException

Posts constraints cs permanently in the constraints network of this: - add them to the data structure, - set the fixed idx, - checks for restrictions

Parameters:

cs - Constraints

Throws:

SolverException - if the constraint is posted twice, posted although reified or reified twice.

postTemp

public void postTemp(Constraint... cs)
              throws ContradictionException

Posts constraints cs temporary, that is, they will be unposted upon backtrack. The unpost instruction is defined by an IOperation saved in the IEnvironment

Parameters:

cs - a set of constraints to add

Throws:

ContradictionException - if the addition of constraints cs detects inconsistency.

SolverException - if a constraint is posted twice, posted although reified or reified twice.

unpost

public void unpost(Constraint... constraints)
            throws SolverException

Remove permanently the constraint c from the constraint network.

Parameters:

constraints - the constraints to remove

Throws:

SolverException - if a constraint is unknown from the model

toString

public String toString()

Return a string describing the CSP defined in this model.

Overrides:

toString in class Object

ref

public Model ref()

Specified by:

ref in interface ISelf<Model>

Returns:

the encapsulated type