io.github.privacystreams.commons.statistic

Class StatisticOperators

java.lang.Object

io.github.privacystreams.commons.statistic.StatisticOperators

@PSOperatorWrapper
public class StatisticOperators
extends java.lang.Object

A helper class to access statistic-related functions

Constructor Summary

Constructors

Constructor and Description
StatisticOperators()

Method Summary

Modifier and Type	Method and Description
static Function<java.util.List<Item>,java.lang.Integer>	count() Count the number of items in the stream and output the number.
static Function<java.util.List<Item>,java.lang.Integer>	count(java.lang.String field) Count the number of valid fields in the stream and output the number.
static Function<java.util.List<Item>,java.lang.Number>	max(java.lang.String numField) Get the max value of a field in the stream.
static Function<java.util.List<Item>,java.lang.Double>	mean(java.lang.String numField) Calculate the average of the number values of a field in the stream.
static Function<java.util.List<Item>,java.lang.Number>	median(java.lang.String numField) Get the median value of a field in the stream.
static Function<java.util.List<Item>,java.lang.Number>	min(java.lang.String numField) Get the min value of a field in the stream.
static Function<java.util.List<Item>,java.lang.Number>	mode(java.lang.String numField) Get the mode value of a field in the stream.
static Function<java.util.List<Item>,java.lang.Double>	range(java.lang.String numField) Calculate the range of the number values of a field in the stream.
static Function<java.util.List<Item>,java.lang.Double>	rms(java.lang.String numField) Calculate the RMS (root mean square) of the number values of a field in the stream.
static Function<java.util.List<Item>,java.lang.Double>	sum(java.lang.String numField) Calculate the sum of the number values of a field in the stream.
static Function<java.util.List<Item>,java.lang.Double>	variance(java.lang.String numField) Calculate the variance of the number values of a field in the stream.

Methods inherited from class java.lang.Object

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

Constructor Detail

StatisticOperators

public StatisticOperators()

Method Detail

count

public static Function<java.util.List<Item>,java.lang.Integer> count()

Count the number of items in the stream and output the number.

Returns:

the function.

count

public static Function<java.util.List<Item>,java.lang.Integer> count(java.lang.String field)

Count the number of valid fields in the stream and output the number.

Parameters:

field - the name of the field to count

Returns:

the function.

range

public static Function<java.util.List<Item>,java.lang.Double> range(java.lang.String numField)

Calculate the range of the number values of a field in the stream. The field values must be in Number type, such as Integer, Double, Long, ... If calculation fails (e.g. there is no item in the stream), the result will be null.

Parameters:

numField - the name of the field, the field value must be a number.

Returns:

the function

sum

public static Function<java.util.List<Item>,java.lang.Double> sum(java.lang.String numField)

Calculate the sum of the number values of a field in the stream. The field values must be in Number type, such as Integer, Double, Long, ... If there is no valid field value in the stream, the "sum" result will be 0.0

Parameters:

numField - the name of the field, the field value must be a number.

Returns:

the function

mean

public static Function<java.util.List<Item>,java.lang.Double> mean(java.lang.String numField)

Calculate the average of the number values of a field in the stream. The field values must be in Number type, such as Integer, Double, Long, ... If calculation fails (e.g. there is no item in the stream), the result will be null.

Parameters:

numField - the name of the field, the field value must be a number.

Returns:

the function

rms

public static Function<java.util.List<Item>,java.lang.Double> rms(java.lang.String numField)

Calculate the RMS (root mean square) of the number values of a field in the stream. The field values must be in Number type, such as Integer, Double, Long, ... If calculation fails (e.g. there is no item in the stream), the result will be null.

Parameters:

numField - the name of the field, the field value must be a number.

Returns:

the function

variance

public static Function<java.util.List<Item>,java.lang.Double> variance(java.lang.String numField)

Calculate the variance of the number values of a field in the stream. The field values must be in Number type, such as Integer, Double, Long, ... If calculation fails (e.g. there is no item in the stream), the result will be null.

Parameters:

numField - the name of the field, the field value must be a number.

Returns:

the function

max

public static Function<java.util.List<Item>,java.lang.Number> max(java.lang.String numField)

Get the max value of a field in the stream. The field values must be in Number type, such as Integer, Double, Long, ... If calculation fails (e.g. there is no item in the stream), the result will be null.

Parameters:

numField - the name of the field, the field value must be a number.

Returns:

the function

min

public static Function<java.util.List<Item>,java.lang.Number> min(java.lang.String numField)

Get the min value of a field in the stream. The field values must be in Number type, such as Integer, Double, Long, ... If calculation fails (e.g. there is no item in the stream), the result will be null.

Parameters:

numField - the name of the field, the field value must be a number.

Returns:

the function

median

public static Function<java.util.List<Item>,java.lang.Number> median(java.lang.String numField)

Get the median value of a field in the stream. The field values must be in Number type, such as Integer, Double, Long, ... If calculation fails (e.g. there is no item in the stream), the result will be null.

Parameters:

numField - the name of the field, the field value must be a number.

Returns:

the function

mode

public static Function<java.util.List<Item>,java.lang.Number> mode(java.lang.String numField)

Get the mode value of a field in the stream. The field values must be in Number type, such as Integer, Double, Long, ... If calculation fails (e.g. there is no item in the stream), the result will be null.

Parameters:

numField - the name of the field, the field value must be a number.

Returns:

the function