org.apache.ignite.ml.genetic

Class RouletteWheelSelectionTask

java.lang.Object

org.apache.ignite.compute.ComputeTaskAdapter<LinkedHashMap<Long,Double>,List<Long>>

org.apache.ignite.ml.genetic.RouletteWheelSelectionTask

All Implemented Interfaces:

Serializable, ComputeTask<LinkedHashMap<Long,Double>,List<Long>>

public class RouletteWheelSelectionTask
extends ComputeTaskAdapter<LinkedHashMap<Long,Double>,List<Long>>

Responsible for performing Roulette Wheel selection.

See Also:

Serialized Form

Constructor Summary

Constructors

Constructor and Description
RouletteWheelSelectionTask(GAConfiguration cfg)

Method Summary

Modifier and Type	Method and Description
@NotNull Map<ComputeJob,ClusterNode>	map(List<ClusterNode> nodes, LinkedHashMap<Long,Double> chromosomeKeyFitness) This method is called to map or split grid task into multiple grid jobs.
List<Long>	reduce(List<ComputeJobResult> list) Return list of parent Chromosomes.
ComputeJobResultPolicy	result(ComputeJobResult res, List<ComputeJobResult> rcvd) Default implementation which will wait for all jobs to complete before calling ComputeTask.reduce(List) method.

Methods inherited from class java.lang.Object

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

Constructor Detail

RouletteWheelSelectionTask

public RouletteWheelSelectionTask(GAConfiguration cfg)

Parameters:

cfg - GAConfiguration

Method Detail

map

@NotNull
public @NotNull Map<ComputeJob,ClusterNode> map(List<ClusterNode> nodes,
                                                         LinkedHashMap<Long,Double> chromosomeKeyFitness)
                                                  throws IgniteException

Description copied from interface: ComputeTask

This method is called to map or split grid task into multiple grid jobs. This is the first method that gets called when task execution starts.

Parameters:

nodes - List of ClusterNode.

chromosomeKeyFitness - Map of key/fitness score pairs.

Returns:

Map of nodes to jobs.

Throws:

IgniteException - If mapping could not complete successfully. This exception will be thrown out of ComputeTaskFuture.get() method.

reduce

public List<Long> reduce(List<ComputeJobResult> list)
                  throws IgniteException

Return list of parent Chromosomes.

Parameters:

list - List of ComputeJobResult.

Returns:

List of Chromosome keys.

Throws:

IgniteException - If reduction or results caused an error. This exception will be thrown out of ComputeTaskFuture.get() method.

result

public ComputeJobResultPolicy result(ComputeJobResult res,
                                     List<ComputeJobResult> rcvd)

Default implementation which will wait for all jobs to complete before calling ComputeTask.reduce(List) method.

If remote job resulted in exception (ComputeJobResult.getException() is not null), then ComputeJobResultPolicy.FAILOVER policy will be returned if the exception is instance of ClusterTopologyException or ComputeExecutionRejectedException, which means that remote node either failed or job execution was rejected before it got a chance to start. In all other cases the exception will be rethrown which will ultimately cause task to fail.

Specified by:

result in interface ComputeTask<LinkedHashMap<Long,Double>,List<Long>>

Overrides:

result in class ComputeTaskAdapter<LinkedHashMap<Long,Double>,List<Long>>

Parameters:

res - Received remote grid executable result.

rcvd - All previously received results.

Returns:

Result policy that dictates how to process further upcoming job results.