eu.stratosphere.example.java.record.kmeans.udfs

Class RecomputeClusterCenter

java.lang.Object

eu.stratosphere.api.common.functions.AbstractFunction

eu.stratosphere.api.java.record.functions.ReduceFunction

eu.stratosphere.example.java.record.kmeans.udfs.RecomputeClusterCenter

All Implemented Interfaces:

Function, GenericReducer<Record,Record>, Serializable

public class RecomputeClusterCenter
extends ReduceFunction
implements Serializable

Reduce PACT computes the new position (coordinate vector) of a cluster center. This is an average computation. Hence, Combinable is annotated and the combine method implemented. Output Format: 0: clusterID 1: clusterVector

See Also:

Serialized Form

Constructor Summary

Constructors

Constructor and Description
RecomputeClusterCenter()

Method Summary

Methods

Modifier and Type	Method and Description
void	combine(Iterator<Record> dataPoints, Collector<Record> out) Computes a pre-aggregated average value of a coordinate vector.
void	reduce(Iterator<Record> dataPoints, Collector<Record> out) Compute the new position (coordinate vector) of a cluster center.

Methods inherited from class eu.stratosphere.api.common.functions.AbstractFunction

close, getIterationRuntimeContext, getRuntimeContext, open, setRuntimeContext

Methods inherited from class java.lang.Object

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

Methods inherited from interface eu.stratosphere.api.common.functions.Function

close, getRuntimeContext, open, setRuntimeContext

Constructor Detail

RecomputeClusterCenter

public RecomputeClusterCenter()

Method Detail

reduce

public void reduce(Iterator<Record> dataPoints,
          Collector<Record> out)

Compute the new position (coordinate vector) of a cluster center.

Specified by:

reduce in interface GenericReducer<Record,Record>

Specified by:

reduce in class ReduceFunction

combine

public void combine(Iterator<Record> dataPoints,
           Collector<Record> out)

Computes a pre-aggregated average value of a coordinate vector.

Specified by:

combine in interface GenericReducer<Record,Record>

Overrides:

combine in class ReduceFunction