ilog.concert

Interface IloConversion

All Superinterfaces:

IloAddable

public interface IloConversion
extends IloAddable

IloConversion objects allow you to locally change the type of one or more variables.

After you create a conversion object, you must explicitly add the object to your model and extract the object so that CPLEX takes it into account. To add the conversion object to your model, use the appropriate overload of the method IloModel.add.

When a variable is created, its type is determined to be one of Int, Float, or Bool. The type of a variable can be queried with the method IloNumVar.getType(). It cannot be changed throughout the lifetime of the variable.

However, it is sometimes necessary to consider a model where, for example, some integer variables are relaxed to be continuous. This is achieved using objects of type IloConversion. By adding an IloConversion object to a model, you can change the types of the variables represented in the IloConversion object for that model only. When solving the model, the changed types are used instead of the original types of the variables. Method IloNumVar.getType() still returns the original variable types.

The type of a variable can be changed only once per model. An attempt to add more than one IloConversion object to a model containing the same variable will cause an exception to be thrown.

To change the type of a variable more than once, you must remove the existing IloConversion object before adding a new IloConversion object. Removing the conversion object for a variable from the model will re-instantiate the original type of variable within that model.

For an example of conversion in use, see the sample AdMIPex6.java distributed with the product.

See Also:

IloNumVarType, IloMPModeler.conversion(ilog.concert.IloNumVar, ilog.concert.IloNumVarType)

Method Summary

Methods

Modifier and Type	Method and Description
IloNumVarType	getType(IloNumVar var) Returns the variable type to which the invoking IloConversion object converts variable var.

Methods inherited from interface ilog.concert.IloAddable

getName, setName

Method Detail

getType

IloNumVarType getType(IloNumVar var)

Returns the variable type to which the invoking IloConversion object converts variable var. If the invoking IloConversion object does not specify a type for that variable, null is returned instead.

Parameters:

var - The variable to be queried for type.

Returns:

The type to which variable var is converted.

See Also:

IloNumVarType