uk.ac.starlink.ttools.filter

Class SortQuantiler

java.lang.Object

uk.ac.starlink.ttools.filter.SortQuantiler

All Implemented Interfaces:

Quantiler

public class SortQuantiler
extends Object
implements Quantiler

Quantiler that retains all data samples, sorts them when ready, and uses the sorted array to answer questions about quantiles. This is exact, but consumes approximately 8 bytes per sample, so not suited for unlimited sized datasets.

Since:

3 Dec 2020

Author:

Mark Taylor

Field Summary

Fields

Modifier and Type	Field and Description
static int	DFLT_BLOCKSIZE Default block size.

Constructor Summary

Constructors

Constructor and Description
SortQuantiler() Constructor with default block size.
SortQuantiler(int blocksize) Constructor with supplied block size.

Method Summary

Modifier and Type	Method and Description
void	acceptDatum(double value) Accepts a value to accumulate for quantile calculations.
void	addQuantiler(Quantiler o) Merges the state of another compatible accumulator into this one; the effect is as if all the Quantiler.acceptDatum(double) calls that were made on other had been made on this one.
double	getValueAtQuantile(double quantile) Returns the value at a given quantile.
void	ready() Call after all data has been accumulated and before quantiles are to be calculated.

Methods inherited from class java.lang.Object

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

Field Detail

DFLT_BLOCKSIZE

public static final int DFLT_BLOCKSIZE

Default block size.

See Also:

Constant Field Values

Constructor Detail

SortQuantiler

public SortQuantiler()

Constructor with default block size.

SortQuantiler

public SortQuantiler(int blocksize)

Constructor with supplied block size.

Parameters:

blocksize - tuning parameter, block size in bytes

Method Detail

acceptDatum

public void acceptDatum(double value)

Description copied from interface: Quantiler

Accepts a value to accumulate for quantile calculations. NaN values are ignored.

Specified by:

acceptDatum in interface Quantiler

Parameters:

value - value to accumulate

addQuantiler

public void addQuantiler(Quantiler o)

Description copied from interface: Quantiler

Merges the state of another compatible accumulator into this one; the effect is as if all the Quantiler.acceptDatum(double) calls that were made on other had been made on this one.

Specified by:

addQuantiler in interface Quantiler

Parameters:

o - compatible quantiler to merge with this

ready

public void ready()

Description copied from interface: Quantiler

Call after all data has been accumulated and before quantiles are to be calculated.

Specified by:

ready in interface Quantiler

getValueAtQuantile

public double getValueAtQuantile(double quantile)

Description copied from interface: Quantiler

Returns the value at a given quantile.

Specified by:

getValueAtQuantile in interface Quantiler

Parameters:

quantile - value in the range 0..1

Returns:

value at quantile, or NaN if no data