org.apache.crunch.lib

Class Sample

java.lang.Object

org.apache.crunch.lib.Sample

public class Sample
extends Object

Constructor Summary

Constructors

Constructor and Description
Sample()

Method Summary

Methods

Modifier and Type	Method and Description
static <S> PCollection<S>	sample(PCollection<S> input, double probability) Output records from the given PCollection with the given probability.
static <S> PCollection<S>	sample(PCollection<S> input, long seed, double probability) Output records from the given PCollection using a given seed.
static <K,V> PTable<K,V>	sample(PTable<K,V> input, double probability) A PTable<K, V> analogue of the sample function.
static <K,V> PTable<K,V>	sample(PTable<K,V> input, long seed, double probability) A PTable<K, V> analogue of the sample function.

Methods inherited from class java.lang.Object

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

Constructor Detail

Sample

public Sample()

Method Detail

sample

public static <S> PCollection<S> sample(PCollection<S> input,
                        double probability)

Output records from the given PCollection with the given probability.

Parameters:

input - The PCollection to sample from

probability - The probability (0.0 < p < 1.0)

Returns:

The output PCollection created from sampling

sample

public static <S> PCollection<S> sample(PCollection<S> input,
                        long seed,
                        double probability)

Output records from the given PCollection using a given seed. Useful for unit testing.

Parameters:

input - The PCollection to sample from

seed - The seed

probability - The probability (0.0 < p < 1.0)

Returns:

The output PCollection created from sampling

sample

public static <K,V> PTable<K,V> sample(PTable<K,V> input,
                       double probability)

A PTable<K, V> analogue of the sample function.

sample

public static <K,V> PTable<K,V> sample(PTable<K,V> input,
                       long seed,
                       double probability)

A PTable<K, V> analogue of the sample function.