uk.ac.starlink.ttools.task

Class Aggregators

java.lang.Object

uk.ac.starlink.ttools.task.Aggregators

public class Aggregators
extends Object

Provides instances of the Aggregator interface.

Since:

16 Nov 2022

Author:

Mark Taylor

Field Summary

Fields

Modifier and Type	Field and Description
static Aggregator	ARRAY_NOBLANKS Aggregator that assembles an array of all non-blank inputs.
static Aggregator	ARRAY_WITHBLANKS Aggregator that assembles an array of all inputs.
static Aggregator	COUNT Aggregator for counting items, with int-valued counter.
static Aggregator	COUNT_LONG Aggregator for counting items, with long-valued counter.
static Aggregator	MAX Aggregator that calculates the maximum.
static Aggregator	MEAN Aggregator that calculates the mean.
static Aggregator	MEDIAN Aggregator that calculates the median.
static Aggregator	MIN Aggregator that calculates the minimum.
static Aggregator	NGOOD Aggregator for counting non-blank items, with int-valued counter.
static Aggregator	NGOOD_LONG Aggregator for counting non-blank items, with long-valued counter.
static Aggregator	POP_STDEV Aggregator that calculates the population standard deviation.
static Aggregator	SAMPLE_STDEV Aggregator that calculates the sample standard deviation.
static Aggregator	SUM Aggregator for summing items.

Method Summary

Modifier and Type	Method and Description
static Aggregator	getAggregator(String aggTxt) Gets an aggregator instance from its name.
static Aggregator[]	getAggregators() Returns an array of useful Aggregator instances.
static String	getOptionsDescription() Returns an XML element listing the possible options for specification of an Aggregator.

Methods inherited from class java.lang.Object

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

Field Detail

COUNT

public static final Aggregator COUNT

Aggregator for counting items, with int-valued counter.

NGOOD

public static final Aggregator NGOOD

Aggregator for counting non-blank items, with int-valued counter.

SUM

public static final Aggregator SUM

Aggregator for summing items.

MEAN

public static final Aggregator MEAN

Aggregator that calculates the mean.

MEDIAN

public static final Aggregator MEDIAN

Aggregator that calculates the median.

SAMPLE_STDEV

public static final Aggregator SAMPLE_STDEV

Aggregator that calculates the sample standard deviation.

POP_STDEV

public static final Aggregator POP_STDEV

Aggregator that calculates the population standard deviation.

MAX

public static final Aggregator MAX

Aggregator that calculates the maximum.

MIN

public static final Aggregator MIN

Aggregator that calculates the minimum.

ARRAY_NOBLANKS

public static final Aggregator ARRAY_NOBLANKS

Aggregator that assembles an array of all non-blank inputs.

ARRAY_WITHBLANKS

public static final Aggregator ARRAY_WITHBLANKS

Aggregator that assembles an array of all inputs.

COUNT_LONG

public static final Aggregator COUNT_LONG

Aggregator for counting items, with long-valued counter.

NGOOD_LONG

public static final Aggregator NGOOD_LONG

Aggregator for counting non-blank items, with long-valued counter.

Method Detail

getAggregators

public static Aggregator[] getAggregators()

Returns an array of useful Aggregator instances.

Returns:

aggregator array

getAggregator

public static Aggregator getAggregator(String aggTxt)

Gets an aggregator instance from its name.

Parameters:

aggTxt - string specification of aggregator

Returns:

aggregator, or null if nothing can be made of it

getOptionsDescription

public static String getOptionsDescription()

Returns an XML element listing the possible options for specification of an Aggregator. This corresponds to the suitable inputs for the getAggregator(String) method.

Returns:

options description in as a <ul> element