Package org.apache.commons.statistics.descriptive

Class Statistics

java.lang.Object

org.apache.commons.statistics.descriptive.Statistics

final class Statistics
extends java.lang.Object

Utility methods for statistics.

Since:

1.1

Field Summary

Fields

Modifier and Type	Field	Description
(package private) static java.util.function.DoubleConsumer	DOUBLE_NOOP	A no-operation double consumer.
private static java.lang.String	INCOMPATIBLE_STATISTICS	Error message for an incompatible statistics.
(package private) static java.util.function.IntConsumer	INT_NOOP	A no-operation int consumer.
(package private) static java.util.function.LongConsumer	LONG_NOOP	A no-operation long consumer.

Constructor Summary

Constructors

Modifier	Constructor	Description
private	Statistics()	No instances.

Method Summary

Modifier and Type	Method	Description
(package private) static <T extends java.util.function.DoubleConsumer> T	add(T statistic, double[] values)	Add all the values to the statistic.
(package private) static <T extends java.util.function.DoubleConsumer> T	add(T statistic, int[] values)	Add all the values to the statistic.
(package private) static <T extends java.util.function.DoubleConsumer> T	add(T statistic, long[] values)	Add all the values to the statistic.
(package private) static void	checkCombineAssignable(FirstMoment a, FirstMoment b)	Check left-hand side argument a is null or else the right-hand side argument b must be run-time assignable to the same class as a so the statistics can be combined.
(package private) static <T extends StatisticResult & StatisticAccumulator<T>> void	checkCombineCompatible(T a, T b)	Check left-hand side argument a is null or else the right-hand side argument b must also be non-null so the statistics can be combined.
(package private) static <T extends StatisticResult & StatisticAccumulator<T>> void	combine(T a, T b)	If the left-hand side argument a is non-null, combine it with the right-hand side argument b.
(package private) static void	combineMoment(FirstMoment a, FirstMoment b)	If the left-hand side argument a is non-null, combine it with the right-hand side argument b.
(package private) static java.util.function.DoubleConsumer	compose(java.util.function.DoubleConsumer... consumers)	Chain the consumers into a single composite consumer.
(package private) static java.util.function.IntConsumer	compose(java.util.function.IntConsumer... consumers)	Chain the consumers into a single composite consumer.
(package private) static java.util.function.LongConsumer	compose(java.util.function.LongConsumer... consumers)	Chain the consumers into a single composite consumer.
(package private) static StatisticResult	getResultAsBigIntegerOrNull(StatisticResult s)	Gets the statistic result using the BigInteger value.
(package private) static StatisticResult	getResultAsDoubleOrNull(StatisticResult s)	Gets the statistic result using the double value.
(package private) static StatisticResult	getResultAsIntOrNull(StatisticResult s)	Gets the statistic result using the int value.
(package private) static StatisticResult	getResultAsLongOrNull(StatisticResult s)	Gets the statistic result using the long value.
(package private) static boolean	zeroVariance(double m1, double m2)	Returns true if the second central moment m2 is effectively zero given the magnitude of the first raw moment m1.

Methods inherited from class java.lang.Object

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

Field Detail

DOUBLE_NOOP

static final java.util.function.DoubleConsumer DOUBLE_NOOP

A no-operation double consumer. This is exposed for testing.

INT_NOOP

static final java.util.function.IntConsumer INT_NOOP

A no-operation int consumer. This is exposed for testing.

LONG_NOOP

static final java.util.function.LongConsumer LONG_NOOP

A no-operation long consumer. This is exposed for testing.

INCOMPATIBLE_STATISTICS

private static final java.lang.String INCOMPATIBLE_STATISTICS

Error message for an incompatible statistics.

See Also:

Constant Field Values

Constructor Detail

Statistics

private Statistics()

No instances.

Method Detail

add

static <T extends java.util.function.DoubleConsumer> T add(T statistic,
                                                           double[] values)

Add all the values to the statistic.

Type Parameters:

T - Type of the statistic

Parameters:

statistic - Statistic.

values - Values.

Returns:

the statistic

add

static <T extends java.util.function.DoubleConsumer> T add(T statistic,
                                                           int[] values)

Add all the values to the statistic.

Type Parameters:

T - Type of the statistic

Parameters:

statistic - Statistic.

values - Values.

Returns:

the statistic

add

static <T extends java.util.function.DoubleConsumer> T add(T statistic,
                                                           long[] values)

Add all the values to the statistic.

Type Parameters:

T - Type of the statistic

Parameters:

statistic - Statistic.

values - Values.

Returns:

the statistic

add

static <T extends java.util.function.IntConsumer> T add(T statistic,
                                                        int[] values)

Add all the values to the statistic.

Type Parameters:

T - Type of the statistic

Parameters:

statistic - Statistic.

values - Values.

Returns:

the statistic

add

static <T extends java.util.function.LongConsumer> T add(T statistic,
                                                         long[] values)

Add all the values to the statistic.

Type Parameters:

T - Type of the statistic

Parameters:

statistic - Statistic.

values - Values.

Returns:

the statistic

zeroVariance

static boolean zeroVariance(double m1,
                            double m2)

Returns true if the second central moment m2 is effectively zero given the magnitude of the first raw moment m1.

This method shares the logic for detecting a zero variance among implementations that divide by the variance (e.g. skewness, kurtosis).

Parameters:

m1 - First raw moment (mean).

m2 - Second central moment (biased variance).

Returns:

true if the variance is zero

compose

static java.util.function.DoubleConsumer compose(java.util.function.DoubleConsumer... consumers)

Chain the consumers into a single composite consumer. Ignore any null consumer. Returns null if all arguments are null.

Parameters:

consumers - Consumers.

Returns:

a composed consumer (or null)

compose

static java.util.function.IntConsumer compose(java.util.function.IntConsumer... consumers)

Chain the consumers into a single composite consumer. Ignore any null consumer. Returns null if all arguments are null.

Parameters:

consumers - Consumers.

Returns:

a composed consumer (or null)

compose

static java.util.function.LongConsumer compose(java.util.function.LongConsumer... consumers)

Chain the consumers into a single composite consumer. Ignore any null consumer. Returns null if all arguments are null.

Parameters:

consumers - Consumers.

Returns:

a composed consumer (or null)

getResultAsIntOrNull

static StatisticResult getResultAsIntOrNull(StatisticResult s)

Gets the statistic result using the int value. Return null is the statistic is null.

Parameters:

s - Statistic.

Returns:

the result or null

getResultAsLongOrNull

static StatisticResult getResultAsLongOrNull(StatisticResult s)

Gets the statistic result using the long value. Return null is the statistic is null.

Parameters:

s - Statistic.

Returns:

the result or null

getResultAsDoubleOrNull

static StatisticResult getResultAsDoubleOrNull(StatisticResult s)

Gets the statistic result using the double value. Return null is the statistic is null.

Parameters:

s - Statistic.

Returns:

the result or null

getResultAsBigIntegerOrNull

static StatisticResult getResultAsBigIntegerOrNull(StatisticResult s)

Gets the statistic result using the BigInteger value. Return null is the statistic is null.

Parameters:

s - Statistic.

Returns:

the result or null

checkCombineCompatible

static <T extends StatisticResult & StatisticAccumulator<T>> void checkCombineCompatible(T a,
                                                                                         T b)

Check left-hand side argument a is null or else the right-hand side argument b must also be non-null so the statistics can be combined.

Type Parameters:

T - StatisticResult being accumulated.

Parameters:

a - LHS.

b - RHS.

Throws:

java.lang.IllegalArgumentException - if the objects cannot be combined

checkCombineAssignable

static void checkCombineAssignable(FirstMoment a,
                                   FirstMoment b)

Check left-hand side argument a is null or else the right-hand side argument b must be run-time assignable to the same class as a so the statistics can be combined.

Parameters:

a - LHS.

b - RHS.

Throws:

java.lang.IllegalArgumentException - if the objects cannot be combined

combine

static <T extends StatisticResult & StatisticAccumulator<T>> void combine(T a,
                                                                          T b)

If the left-hand side argument a is non-null, combine it with the right-hand side argument b.

Type Parameters:

T - StatisticResult being accumulated.

Parameters:

a - LHS.

b - RHS.

combineMoment

static void combineMoment(FirstMoment a,
                          FirstMoment b)

If the left-hand side argument a is non-null, combine it with the right-hand side argument b. Assumes that the RHS is run-time assignable to the same class as LHS.

Parameters:

a - LHS.

b - RHS.

See Also:

checkCombineAssignable(FirstMoment, FirstMoment)