ilog.opl

Class IloOplCplexBasis

java.lang.Object

ilog.opl.IloOplCplexBasis

public class IloOplCplexBasis
extends java.lang.Object

Utility for CPLEX warm start of LP problems. An instance of this class can be used to save basis information for one instance of IloCplex and restore it on other instances of IloCplex.

See Also:

IloCplex::setBasisStatuses(BasisStatusArray,IloNumVarArray,BasisStatusArray,IloConstraintArray)IloCplex::getBasisStatuses(BasisStatusArray,IloNumVarArray,BasisStatusArray,IloConstraintArray)

Method Summary

Methods

Modifier and Type	Method and Description
void	attach(IloNumVarMap vars, IloIntMap statuses) Attach a variable map vars to a value map statuses.
void	end() Clears the memory used by this object
boolean	getBasis(IloCplex cplex) Saves basis information for a CPLEX instance.
int	getNcols() Returns the number of columns in the currently saved basis.
int	getNrows() Returns the number of rows in the currently saved basis.
int	getStatus() Returns the CPLEX status of the last invocation of CPLEX API.
boolean	setBasis(IloCplex cplex) Restores basis information for a CPLEX instance.

Methods inherited from class java.lang.Object

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

Method Detail

getBasis

public boolean getBasis(IloCplex cplex)

Saves basis information for a CPLEX instance.

Parameters:

cplex - Saves the basis currently available on the given CPLEX instance.

Returns:

IloTrue if the basis was successfully saved.

setBasis

public boolean setBasis(IloCplex cplex)

Restores basis information for a CPLEX instance. This utility can restore bases only if the problem of the given CPLEX instance has exactly the number of rows and columns as the problem it was taken from.

Parameters:

cplex - Restores this basis on the given CPLEX instance.

Returns:

IloTrue if the basis was successfully restored.

attach

public void attach(IloNumVarMap vars,
          IloIntMap statuses)

Attach a variable map vars to a value map statuses. After some attachments have been done, only the elements with attachments are taken into account to get/set basis.

Parameters:

vars - The variable map to be attached.

statuses - The value map.

end

public void end()

Clears the memory used by this object

getStatus

public int getStatus()

Returns the CPLEX status of the last invocation of CPLEX API.

Returns:

An integer to indicate the status of the CPLEX instance.

getNrows

public int getNrows()

Returns the number of rows in the currently saved basis.

Returns:

An integer to indicate the number of rows in the currently saved basis.

getNcols

public int getNcols()

Returns the number of columns in the currently saved basis.

Returns:

An integer to indicate the number of columns in the currently saved basis.