org.apache.datasketches.pig.hll

Class SketchToEstimateAndErrorBounds

java.lang.Object

org.apache.pig.EvalFunc<org.apache.pig.data.Tuple>

org.apache.datasketches.pig.hll.SketchToEstimateAndErrorBounds

public class SketchToEstimateAndErrorBounds
extends org.apache.pig.EvalFunc<org.apache.pig.data.Tuple>

This is a User Defined Function (UDF) for obtaining the unique count estimate along with a lower and upper bound from an HllSketch.

The result is a tuple with three double values: estimate, lower bound and upper bound. The bounds are given at 95.5% confidence.

Author:

Alexander Saydakov

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
SketchToEstimateAndErrorBounds()

Method Summary

Modifier and Type	Method and Description
org.apache.pig.data.Tuple	exec(org.apache.pig.data.Tuple sketchTuple)
org.apache.pig.impl.logicalLayer.schema.Schema	outputSchema(org.apache.pig.impl.logicalLayer.schema.Schema input) The output is a Sketch Result Tuple Schema.

Methods inherited from class org.apache.pig.EvalFunc

allowCompileTimeCalculation, finish, getArgToFuncMapping, getCacheFiles, getInputSchema, getLoadCaster, getLogger, getPigLogger, getReporter, getReturnType, getSchemaName, getSchemaType, getShipFiles, isAsynchronous, needEndOfAllInputProcessing, progress, setEndOfAllInput, setInputSchema, setPigLogger, setReporter, setUDFContextSignature, warn

Methods inherited from class java.lang.Object

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

Constructor Detail

SketchToEstimateAndErrorBounds

public SketchToEstimateAndErrorBounds()

Method Detail

exec

public org.apache.pig.data.Tuple exec(org.apache.pig.data.Tuple sketchTuple)
                               throws IOException

Specified by:

exec in class org.apache.pig.EvalFunc<org.apache.pig.data.Tuple>

Throws:

IOException

outputSchema

public org.apache.pig.impl.logicalLayer.schema.Schema outputSchema(org.apache.pig.impl.logicalLayer.schema.Schema input)

The output is a Sketch Result Tuple Schema.

Overrides:

outputSchema in class org.apache.pig.EvalFunc<org.apache.pig.data.Tuple>