uk.ac.starlink.ttools.filter

Class GKArray

java.lang.Object

uk.ac.starlink.ttools.filter.GKArray

public class GKArray
extends Object

An implementation of the quantile sketch of Greenwald and Khanna. Acquired from https://github.com/DataDog/sketches-java.

Constructor Summary

Constructors

Constructor and Description
GKArray(double rankAccuracy)

Method Summary

Modifier and Type	Method and Description
void	accept(double value) Adds a value to the sketch.
void	accept(double value, long count) Adds a value to the sketch as many times as specified by count.
GKArray	copy()
double	getCount()
double	getMaxValue()
double	getMinValue()
double	getRankAccuracy()
double	getValueAtQuantile(double quantile)
double[]	getValuesAtQuantiles(double[] quantiles)
boolean	isEmpty()
void	mergeWith(GKArray other) Merges the other sketch into this one.

Methods inherited from class java.lang.Object

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

Constructor Detail

GKArray

public GKArray(double rankAccuracy)

Method Detail

getRankAccuracy

public double getRankAccuracy()

accept

public void accept(double value)

Adds a value to the sketch.

Parameters:

value - the value to be added

accept

public void accept(double value,
                   long count)

Adds a value to the sketch as many times as specified by count.

Parameters:

value - the value to be added

count - the number of times the value is to be added

Throws:

IllegalArgumentException - if count is negative

mergeWith

public void mergeWith(GKArray other)

Merges the other sketch into this one. After this operation, this sketch encodes the values that were added to both this and the other sketches.

Parameters:

other - the sketch to be merged into this one

Throws:

NullPointerException - if other is null

copy

public GKArray copy()

Returns:

a (deep) copy of this sketch

isEmpty

public boolean isEmpty()

Returns:

iff no value has been added to this sketch

getCount

public double getCount()

Returns:

the total number of values that have been added to this sketch

getMinValue

public double getMinValue()

Returns:

the minimum value that has been added to this sketch

Throws:

NoSuchElementException - if the sketch is empty

getMaxValue

public double getMaxValue()

Returns:

the maximum value that has been added to this sketch

Throws:

NoSuchElementException - if the sketch is empty

getValueAtQuantile

public double getValueAtQuantile(double quantile)

Parameters:

quantile - a number between 0 and 1 (both included)

Returns:

the value at the specified quantile

Throws:

NoSuchElementException - if the sketch is empty

getValuesAtQuantiles

public double[] getValuesAtQuantiles(double[] quantiles)

Parameters:

quantiles - number between 0 and 1 (both included)

Returns:

the values at the respective specified quantiles

Throws:

NoSuchElementException - if the sketch is empty