org.apache.flink.api.java.functions

Class SampleWithFraction<T>

java.lang.Object

org.apache.flink.api.common.functions.AbstractRichFunction

org.apache.flink.api.common.functions.RichMapPartitionFunction<T,T>

org.apache.flink.api.java.functions.SampleWithFraction<T>

Type Parameters:

T -

All Implemented Interfaces:

Serializable, Function, MapPartitionFunction<T,T>, RichFunction

@Internal
public class SampleWithFraction<T>
extends RichMapPartitionFunction<T,T>

A map partition function wrapper for sampling algorithms with fraction, the sample algorithm takes the partition iterator as input.

See Also:

Serialized Form

Constructor Summary

Constructors

Constructor and Description
SampleWithFraction(boolean withReplacement, double fraction, long seed) Create a function instance of SampleWithFraction.

Method Summary

Modifier and Type	Method and Description
void	mapPartition(Iterable<T> values, Collector<T> out) A user-implemented function that modifies or transforms an incoming object.

Methods inherited from class org.apache.flink.api.common.functions.AbstractRichFunction

close, getIterationRuntimeContext, getRuntimeContext, open, setRuntimeContext

Methods inherited from class java.lang.Object

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

Constructor Detail

SampleWithFraction

public SampleWithFraction(boolean withReplacement,
                          double fraction,
                          long seed)

Create a function instance of SampleWithFraction.

Parameters:

withReplacement - Whether element can be selected more than once.

fraction - Probability that each element is selected.

seed - random number generator seed.

Method Detail

mapPartition

public void mapPartition(Iterable<T> values,
                         Collector<T> out)
                  throws Exception

Description copied from interface: MapPartitionFunction

A user-implemented function that modifies or transforms an incoming object.

Specified by:

mapPartition in interface MapPartitionFunction<T,T>

Specified by:

mapPartition in class RichMapPartitionFunction<T,T>

Parameters:

values - All records for the mapper

out - The collector to hand results to.

Throws:

Exception - This method may throw exceptions. Throwing an exception will cause the operation to fail and may trigger recovery.