org.apache.hama.graph

Class AbsDiffAggregator

java.lang.Object

org.apache.hama.graph.AbstractAggregator<org.apache.hadoop.io.DoubleWritable,Vertex<?,?,org.apache.hadoop.io.DoubleWritable>>

org.apache.hama.graph.AbsDiffAggregator

All Implemented Interfaces:

Aggregator<org.apache.hadoop.io.DoubleWritable,Vertex<?,?,org.apache.hadoop.io.DoubleWritable>>

Direct Known Subclasses:

AverageAggregator

public class AbsDiffAggregator
extends AbstractAggregator<org.apache.hadoop.io.DoubleWritable,Vertex<?,?,org.apache.hadoop.io.DoubleWritable>>

A absolute difference aggregator, it collects values before the compute and after the compute, then calculates the difference and globally accumulates (sums them up) them.

Constructor Summary

Constructors

Constructor and Description
AbsDiffAggregator()

Method Summary

Methods

Modifier and Type	Method and Description
void	aggregate(Vertex<?,?,org.apache.hadoop.io.DoubleWritable> vertex, org.apache.hadoop.io.DoubleWritable value) Observes a value of a vertex after the compute method.
void	aggregate(Vertex<?,?,org.apache.hadoop.io.DoubleWritable> v, org.apache.hadoop.io.DoubleWritable oldValue, org.apache.hadoop.io.DoubleWritable newValue) Observes the old value of a vertex and the new value at the same time.
org.apache.hadoop.io.DoubleWritable	getValue() Gets the value of the aggregator.

Methods inherited from class org.apache.hama.graph.AbstractAggregator

finalizeAggregation, getTimesAggregated, toString

Methods inherited from class java.lang.Object

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

Constructor Detail

AbsDiffAggregator

public AbsDiffAggregator()

Method Detail

aggregate

public void aggregate(Vertex<?,?,org.apache.hadoop.io.DoubleWritable> v,
             org.apache.hadoop.io.DoubleWritable oldValue,
             org.apache.hadoop.io.DoubleWritable newValue)

Description copied from class: AbstractAggregator

Observes the old value of a vertex and the new value at the same time. This is intended to be overridden by the user and is just an empty implementation in this class.Please make sure that you are null-checking vertex, since on a master task this will always be null.

Overrides:

aggregate in class AbstractAggregator<org.apache.hadoop.io.DoubleWritable,Vertex<?,?,org.apache.hadoop.io.DoubleWritable>>

aggregate

public void aggregate(Vertex<?,?,org.apache.hadoop.io.DoubleWritable> vertex,
             org.apache.hadoop.io.DoubleWritable value)

Description copied from class: AbstractAggregator

Observes a value of a vertex after the compute method. This is intended to be overriden by the user and is just an empty implementation in this class. Please make sure that you are null-checking vertex, since on a master task this will always be null.

Specified by:

aggregate in interface Aggregator<org.apache.hadoop.io.DoubleWritable,Vertex<?,?,org.apache.hadoop.io.DoubleWritable>>

Overrides:

aggregate in class AbstractAggregator<org.apache.hadoop.io.DoubleWritable,Vertex<?,?,org.apache.hadoop.io.DoubleWritable>>

getValue

public org.apache.hadoop.io.DoubleWritable getValue()

Description copied from class: AbstractAggregator

Gets the value of the aggregator. This is intended to be overridden by the user and is just an empty implementation in this class (returns null).

Specified by:

getValue in interface Aggregator<org.apache.hadoop.io.DoubleWritable,Vertex<?,?,org.apache.hadoop.io.DoubleWritable>>

Overrides:

getValue in class AbstractAggregator<org.apache.hadoop.io.DoubleWritable,Vertex<?,?,org.apache.hadoop.io.DoubleWritable>>