Class IntegerStrategy.ConfigurableStrategy

java.lang.Object

org.ojalgo.optimisation.integer.IntegerStrategy.ConfigurableStrategy

All Implemented Interfaces:

IntegerStrategy

Enclosing interface:

IntegerStrategy

public static final class IntegerStrategy.ConfigurableStrategy
extends Object
implements IntegerStrategy

Apart from being able to configure various standard properties, you can also provide your own ModelStrategy factory.

Nested Class Summary

Nested classes/interfaces inherited from interface IntegerStrategy

IntegerStrategy.ConfigurableStrategy, IntegerStrategy.GMICutConfiguration

Field Summary

Fields

Modifier and Type	Field	Description
private final BiFunction<ExpressionsBasedModel, IntegerStrategy, ModelStrategy>	myFactory
private final NumberContext	myGapTolerance
private final IntegerStrategy.GMICutConfiguration	myGMICutConfiguration
private final NumberContext	myIntegralityTolerance
private final IntSupplier	myParallelism
private final Comparator<NodeKey>[]	myPriorityDefinitions

Fields inherited from interface IntegerStrategy

DEFAULT

Constructor Summary

Constructors

Constructor	Description
ConfigurableStrategy(IntSupplier parallelism, Comparator<NodeKey>[] definitions, NumberContext integrality, NumberContext gap, BiFunction<ExpressionsBasedModel, IntegerStrategy, ModelStrategy> factory, IntegerStrategy.GMICutConfiguration configuration)

Method Summary

Modifier and Type	Method	Description
IntegerStrategy.ConfigurableStrategy	addPriorityDefinitions(Comparator<NodeKey>... additionalDefinitions)	Retains any existing definitions, but adds these to be used rather than the existing.
int	countUniqueStrategies()
NumberContext	getGapTolerance()	The MIP gap is the difference between the best integer solution found so far and a node's relaxed non-integer solution.
IntegerStrategy.GMICutConfiguration	getGMICutConfiguration()
NumberContext	getIntegralityTolerance()	Used to determine if a variable value is integer or not
List<Comparator<NodeKey>>	getWorkerPriorities()	There will be 1 worker thread per item in the returned List.
ModelStrategy	newModelStrategy(ExpressionsBasedModel model)
IntegerStrategy.ConfigurableStrategy	withGapTolerance(NumberContext newTolerance)	Change the MIP gap
IntegerStrategy.ConfigurableStrategy	withGMICutConfiguration(IntegerStrategy.GMICutConfiguration newConfiguration)
IntegerStrategy.ConfigurableStrategy	withModelStrategyFactory(BiFunction<ExpressionsBasedModel, IntegerStrategy, ModelStrategy> newFactory)	Create a sub-class of ModelStrategy and provide a factory method for it here.
IntegerStrategy.ConfigurableStrategy	withParallelism(IntSupplier newParallelism)	How many threads will be used? Perhaps use Parallelism to obtain a suitable value.
IntegerStrategy.ConfigurableStrategy	withPriorityDefinitions(Comparator<NodeKey>... newDefinitions)	Replace the priority definitions with these ones.

Methods inherited from class Object

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

Field Details

myFactory

private final BiFunction<ExpressionsBasedModel, IntegerStrategy, ModelStrategy> myFactory

myGapTolerance

private final NumberContext myGapTolerance

myGMICutConfiguration

private final IntegerStrategy.GMICutConfiguration myGMICutConfiguration

myIntegralityTolerance

private final NumberContext myIntegralityTolerance

myParallelism

private final IntSupplier myParallelism

myPriorityDefinitions

private final Comparator<NodeKey>[] myPriorityDefinitions

Constructor Details

ConfigurableStrategy

ConfigurableStrategy(IntSupplier parallelism,
 Comparator<NodeKey>[] definitions,
 NumberContext integrality,
 NumberContext gap,
 BiFunction<ExpressionsBasedModel, IntegerStrategy, ModelStrategy> factory,
 IntegerStrategy.GMICutConfiguration configuration)

Method Details

addPriorityDefinitions

public IntegerStrategy.ConfigurableStrategy addPriorityDefinitions(Comparator<NodeKey>... additionalDefinitions)

Retains any existing definitions, but adds these to be used rather than the existing. If there are enough threads both these additional and the previously existing definitions will be used.

countUniqueStrategies

public int countUniqueStrategies()

Specified by:

countUniqueStrategies in interface IntegerStrategy

getGapTolerance

public NumberContext getGapTolerance()

Description copied from interface: IntegerStrategy

The MIP gap is the difference between the best integer solution found so far and a node's relaxed non-integer solution. The relative MIP gap is that difference divided by the optimal value (approximated by the currently best integer solution). If the gap (absolute or relative) is too small, then the corresponding branch is terminated as it is deemed unlikely or too "expensive" to find better integer solutions there.

Specified by:

getGapTolerance in interface IntegerStrategy

Returns:

The tolerance context used to determine if the gap is too small or not

getGMICutConfiguration

public IntegerStrategy.GMICutConfiguration getGMICutConfiguration()

Specified by:

getGMICutConfiguration in interface IntegerStrategy

getIntegralityTolerance

public NumberContext getIntegralityTolerance()

Description copied from interface: IntegerStrategy

Used to determine if a variable value is integer or not

Specified by:

getIntegralityTolerance in interface IntegerStrategy

getWorkerPriorities

public List<Comparator<NodeKey>> getWorkerPriorities()

Description copied from interface: IntegerStrategy

There will be 1 worker thread per item in the returned List. The Comparator instances need not be unique. Used to prioritise among the nodes waiting to be evaluated.

Specified by:

getWorkerPriorities in interface IntegerStrategy

newModelStrategy

public ModelStrategy newModelStrategy(ExpressionsBasedModel model)

Specified by:

newModelStrategy in interface IntegerStrategy

withGapTolerance

public IntegerStrategy.ConfigurableStrategy withGapTolerance(NumberContext newTolerance)

Change the MIP gap

withGMICutConfiguration

public IntegerStrategy.ConfigurableStrategy withGMICutConfiguration(IntegerStrategy.GMICutConfiguration newConfiguration)

withModelStrategyFactory

public IntegerStrategy.ConfigurableStrategy withModelStrategyFactory(BiFunction<ExpressionsBasedModel, IntegerStrategy, ModelStrategy> newFactory)

Create a sub-class of ModelStrategy and provide a factory method for it here.

withParallelism

public IntegerStrategy.ConfigurableStrategy withParallelism(IntSupplier newParallelism)

How many threads will be used? Perhaps use Parallelism to obtain a suitable value.

withPriorityDefinitions

public IntegerStrategy.ConfigurableStrategy withPriorityDefinitions(Comparator<NodeKey>... newDefinitions)

Replace the priority definitions with these ones.