datafu.pig.stats

Class Median

java.lang.Object

org.apache.pig.EvalFunc<T>

datafu.pig.util.ContextualEvalFunc<T>

datafu.pig.util.SimpleEvalFunc<org.apache.pig.data.Tuple>

datafu.pig.stats.Quantile

datafu.pig.stats.Median

public class Median
extends Quantile

Computes the median for a sorted input bag, using type R-2 estimation. This is a convenience wrapper around Quantile.

N.B., all the data is pushed to a single reducer per key, so make sure some partitioning is done (e.g., group by 'day') if the data is too large. That is, this isn't distributed median.

See Also:

Quantile

Nested Class Summary

Nested classes/interfaces inherited from class org.apache.pig.EvalFunc

org.apache.pig.EvalFunc.SchemaType

Field Summary

Fields inherited from class org.apache.pig.EvalFunc

log, pigLogger, reporter, returnType

Constructor Summary

Constructors

Constructor and Description
Median()

Method Summary

Methods inherited from class datafu.pig.stats.Quantile

call, outputSchema

Methods inherited from class datafu.pig.util.SimpleEvalFunc

exec, getReturnType

Methods inherited from class datafu.pig.util.ContextualEvalFunc

getContextProperties, getInstanceName, getInstanceProperties, onReady, setUDFContextSignature

Methods inherited from class org.apache.pig.EvalFunc

allowCompileTimeCalculation, finish, getArgToFuncMapping, getCacheFiles, getInputSchema, getLogger, getPigLogger, getReporter, getSchemaName, getSchemaType, getShipFiles, isAsynchronous, progress, setInputSchema, setPigLogger, setReporter, warn

Methods inherited from class java.lang.Object

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

Constructor Detail

Median

public Median()