org.apache.spark.rdd

Class PartitionwiseSampledRDD<T,U>

Object

org.apache.spark.rdd.RDD<U>

org.apache.spark.rdd.PartitionwiseSampledRDD<T,U>

All Implemented Interfaces:

java.io.Serializable, Logging

public class PartitionwiseSampledRDD<T,U>
extends RDD<U>

A RDD sampled from its parent RDD partition-wise. For each partition of the parent RDD, a user-specified RandomSampler instance is used to obtain a random sample of the records in the partition. The random seeds assigned to the samplers are guaranteed to have different values.

See Also:

Serialized Form

Constructor Summary

Constructors

Constructor and Description
PartitionwiseSampledRDD(RDD<T> prev, RandomSampler<T,U> sampler, boolean preservesPartitioning, long seed, scala.reflect.ClassTag<T> evidence$1, scala.reflect.ClassTag<U> evidence$2)

Method Summary

Methods

Modifier and Type	Method and Description
scala.collection.Iterator<U>	compute(Partition splitIn, TaskContext context) :: DeveloperApi :: Implemented by subclasses to compute a given partition.
Partition[]	getPartitions() Implemented by subclasses to return the set of partitions in this RDD.
scala.collection.Seq<String>	getPreferredLocations(Partition split) Optionally overridden by subclasses to specify placement preferences.
scala.Option<Partitioner>	partitioner() Optionally overridden by subclasses to specify how they are partitioned.

Methods inherited from class org.apache.spark.rdd.RDD

aggregate, cache, cartesian, checkpoint, checkpointData, coalesce, collect, collect, collectPartitions, computeOrReadCheckpoint, conf, context, count, countApprox, countApproxDistinct, countApproxDistinct, countByValue, countByValueApprox, creationSite, dependencies, distinct, distinct, doCheckpoint, doubleRDDToDoubleRDDFunctions, elementClassTag, filter, filterWith, first, flatMap, flatMapWith, fold, foreach, foreachPartition, foreachWith, getCheckpointFile, getCreationSite, getNarrowAncestors, getStorageLevel, glom, groupBy, groupBy, groupBy, id, intersection, intersection, intersection, isCheckpointed, isEmpty, iterator, keyBy, map, mapPartitions, mapPartitionsWithContext, mapPartitionsWithIndex, mapPartitionsWithSplit, mapWith, markCheckpointed, max, min, name, numericRDDToDoubleRDDFunctions, partitions, persist, persist, pipe, pipe, pipe, preferredLocations, randomSplit, rddToAsyncRDDActions, rddToOrderedRDDFunctions, rddToPairRDDFunctions, rddToSequenceFileRDDFunctions, reduce, repartition, retag, retag, sample, saveAsObjectFile, saveAsTextFile, saveAsTextFile, setName, sortBy, sparkContext, subtract, subtract, subtract, take, takeOrdered, takeSample, toArray, toDebugString, toJavaRDD, toLocalIterator, top, toString, treeAggregate, treeReduce, union, unpersist, zip, zipPartitions, zipPartitions, zipPartitions, zipPartitions, zipPartitions, zipPartitions, zipWithIndex, zipWithUniqueId

Methods inherited from class Object

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

Methods inherited from interface org.apache.spark.Logging

initializeIfNecessary, initializeLogging, isTraceEnabled, log_, log, logDebug, logDebug, logError, logError, logInfo, logInfo, logName, logTrace, logTrace, logWarning, logWarning

Constructor Detail

PartitionwiseSampledRDD

public PartitionwiseSampledRDD(RDD<T> prev,
                       RandomSampler<T,U> sampler,
                       boolean preservesPartitioning,
                       long seed,
                       scala.reflect.ClassTag<T> evidence$1,
                       scala.reflect.ClassTag<U> evidence$2)

Method Detail

partitioner

public scala.Option<Partitioner> partitioner()

Description copied from class: RDD

Optionally overridden by subclasses to specify how they are partitioned.

Overrides:

partitioner in class RDD<U>

getPartitions

public Partition[] getPartitions()

Description copied from class: RDD

Implemented by subclasses to return the set of partitions in this RDD. This method will only be called once, so it is safe to implement a time-consuming computation in it.

getPreferredLocations

public scala.collection.Seq<String> getPreferredLocations(Partition split)

Description copied from class: RDD

Optionally overridden by subclasses to specify placement preferences.

compute

public scala.collection.Iterator<U> compute(Partition splitIn,
                                   TaskContext context)

Description copied from class: RDD

:: DeveloperApi :: Implemented by subclasses to compute a given partition.

Specified by:

compute in class RDD<U>