Apache Commons Math 3.6.1 · org.apache.commons.math3.stat.StatUtils

Modifier and Type	Field and Description
private static final GeometricMean	GEOMETRIC_MEAN geometric mean
private static final UnivariateStatistic	MAX max
private static final UnivariateStatistic	MEAN mean
private static final UnivariateStatistic	MIN min
private static final Percentile	PERCENTILE percentile
private static final UnivariateStatistic	PRODUCT prod
private static final UnivariateStatistic	SUM sum
private static final UnivariateStatistic	SUM_OF_LOGS sumLog
private static final UnivariateStatistic	SUM_OF_SQUARES sumSq
private static final Variance	VARIANCE variance

Access	Constructor and Description
private	StatUtils() Private Constructor

Method Summary

Modifier and Type	Method and Description
public static double	Returns: the geometric mean of the values or Double.NaN if the array is empty geometricMean(final double[] the input array values) Returns the geometric mean of the entries in the input array, or `Double.NaN` if the array is empty.
public static double	Returns: the geometric mean of the values or Double.NaN if length = 0 geometricMean(final double[] the input array values, final int index of the first array element to include begin, final int the number of elements to include length) Returns the geometric mean of the entries in the specified portion of the input array, or `Double.NaN` if the designated subarray is empty.
private static double[]	Returns: array of array of the most frequently occurring element(s) sorted in ascending order. getMode(double[] input data values, final int index (0-based) of the first array element to include begin, final int the number of elements to include length) Private helper method.
public static double	Returns: the maximum of the values or Double.NaN if the array is empty max(final double[] the input array values) Returns the maximum of the entries in the input array, or `Double.NaN` if the array is empty.
public static double	Returns: the maximum of the values or Double.NaN if length = 0 max(final double[] the input array values, final int index of the first array element to include begin, final int the number of elements to include length) Returns the maximum of the entries in the specified portion of the input array, or `Double.NaN` if the designated subarray is empty.
public static double	Returns: the mean of the values or Double.NaN if the array is empty mean(final double[] the input array values) Returns the arithmetic mean of the entries in the input array, or `Double.NaN` if the array is empty.
public static double	Returns: the mean of the values or Double.NaN if length = 0 mean(final double[] the input array values, final int index of the first array element to include begin, final int the number of elements to include length) Returns the arithmetic mean of the entries in the specified portion of the input array, or `Double.NaN` if the designated subarray is empty.
public static double	Returns: mean of paired differences meanDifference(final double[] the first array sample1, final double[] the second array sample2) Returns the mean of the (signed) differences between corresponding elements of the input arrays -- i.e., sum(sample1[i] - sample2[i]) / sample1.length.
public static double	Returns: the minimum of the values or Double.NaN if the array is empty min(final double[] the input array values) Returns the minimum of the entries in the input array, or `Double.NaN` if the array is empty.
public static double	Returns: the minimum of the values or Double.NaN if length = 0 min(final double[] the input array values, final int index of the first array element to include begin, final int the number of elements to include length) Returns the minimum of the entries in the specified portion of the input array, or `Double.NaN` if the designated subarray is empty.
public static double[]	Returns: array of array of the most frequently occurring element(s) sorted in ascending order. mode(double[] input data sample) Returns the sample mode(s).
public static double[]	Returns: array of array of the most frequently occurring element(s) sorted in ascending order. mode(double[] input data sample, final int index (0-based) of the first array element to include begin, final int the number of elements to include length) Returns the sample mode(s).
public static double[]	Returns: normalized (standardized) sample. normalize(final double[] Sample to normalize. sample) Normalize (standardize) the sample, so it is has a mean of 0 and a standard deviation of 1.
public static double	Returns: the percentile value or Double.NaN if the array is empty percentile(final double[] input array of values values, final double the percentile value to compute p) Returns an estimate of the `p`th percentile of the values in the `values` array.
public static double	Returns: the percentile value percentile(final double[] array of input values values, final int the first (0-based) element to include in the computation begin, final int the number of array elements to include length, final double the percentile to compute p) Returns an estimate of the `p`th percentile of the values in the `values` array, starting with the element in (0-based) position `begin` in the array and including `length` values.
public static double	Returns: the population variance of the values or Double.NaN if the array is empty populationVariance(final double[] the input array values) Returns the population variance of the entries in the input array, or `Double.NaN` if the array is empty.
public static double	Returns: the population variance of the values or Double.NaN if length = 0 populationVariance(final double[] the input array values, final int index of the first array element to include begin, final int the number of elements to include length) Returns the population variance of the entries in the specified portion of the input array, or `Double.NaN` if the designated subarray is empty.
public static double	Returns: the population variance of the values or Double.NaN if length = 0 populationVariance(final double[] the input array values, final double the precomputed mean value mean, final int index of the first array element to include begin, final int the number of elements to include length) Returns the population variance of the entries in the specified portion of the input array, using the precomputed mean value.
public static double	Returns: the population variance of the values or Double.NaN if the array is empty populationVariance(final double[] the input array values, final double the precomputed mean value mean) Returns the population variance of the entries in the input array, using the precomputed mean value.
public static double	Returns: the product of the values or Double.NaN if the array is empty product(final double[] the input array values) Returns the product of the entries in the input array, or `Double.NaN` if the array is empty.
public static double	Returns: the product of the values or Double.NaN if length = 0 product(final double[] the input array values, final int index of the first array element to include begin, final int the number of elements to include length) Returns the product of the entries in the specified portion of the input array, or `Double.NaN` if the designated subarray is empty.
public static double	Returns: the sum of the values or `Double.NaN` if the array is empty sum(final double[] array of values to sum values) Returns the sum of the values in the input array, or `Double.NaN` if the array is empty.
public static double	Returns: the sum of the values or Double.NaN if length = 0 sum(final double[] the input array values, final int index of the first array element to include begin, final int the number of elements to include length) Returns the sum of the entries in the specified portion of the input array, or `Double.NaN` if the designated subarray is empty.
public static double	Returns: sum of paired differences sumDifference(final double[] the first array sample1, final double[] the second array sample2) Returns the sum of the (signed) differences between corresponding elements of the input arrays -- i.e., sum(sample1[i] - sample2[i]).
public static double	Returns: the sum of the natural logs of the values or Double.NaN if the array is empty sumLog(final double[] the input array values) Returns the sum of the natural logs of the entries in the input array, or `Double.NaN` if the array is empty.
public static double	Returns: the sum of the natural logs of the values or Double.NaN if length = 0 sumLog(final double[] the input array values, final int index of the first array element to include begin, final int the number of elements to include length) Returns the sum of the natural logs of the entries in the specified portion of the input array, or `Double.NaN` if the designated subarray is empty.
public static double	Returns: the sum of the squared values or `Double.NaN` if the array is empty sumSq(final double[] input array values) Returns the sum of the squares of the entries in the input array, or `Double.NaN` if the array is empty.
public static double	Returns: the sum of the squares of the values or Double.NaN if length = 0 sumSq(final double[] the input array values, final int index of the first array element to include begin, final int the number of elements to include length) Returns the sum of the squares of the entries in the specified portion of the input array, or `Double.NaN` if the designated subarray is empty.
public static double	Returns: the variance of the values or Double.NaN if the array is empty variance(final double[] the input array values) Returns the variance of the entries in the input array, or `Double.NaN` if the array is empty.
public static double	Returns: the variance of the values or Double.NaN if length = 0 variance(final double[] the input array values, final int index of the first array element to include begin, final int the number of elements to include length) Returns the variance of the entries in the specified portion of the input array, or `Double.NaN` if the designated subarray is empty.
public static double	Returns: the variance of the values or Double.NaN if length = 0 variance(final double[] the input array values, final double the precomputed mean value mean, final int index of the first array element to include begin, final int the number of elements to include length) Returns the variance of the entries in the specified portion of the input array, using the precomputed mean value.
public static double	Returns: the variance of the values or Double.NaN if the array is empty variance(final double[] the input array values, final double the precomputed mean value mean) Returns the variance of the entries in the input array, using the precomputed mean value.
public static double	Returns: variance of paired differences varianceDifference(final double[] the first array sample1, final double[] the second array sample2, double the mean difference between corresponding entries meanDifference) Returns the variance of the (signed) differences between corresponding elements of the input arrays -- i.e., var(sample1[i] - sample2[i]).

Inherited from java.lang.Object:: clone equals finalize getClass hashCode notify notifyAll toString wait wait wait

GEOMETRIC_MEAN	back to summary
private static final GeometricMean GEOMETRIC_MEAN geometric mean

MAX	back to summary
private static final UnivariateStatistic MAX max

MEAN	back to summary
private static final UnivariateStatistic MEAN mean

MIN	back to summary
private static final UnivariateStatistic MIN min

PERCENTILE	back to summary
private static final Percentile PERCENTILE percentile

PRODUCT	back to summary
private static final UnivariateStatistic PRODUCT prod

SUM	back to summary
private static final UnivariateStatistic SUM sum

SUM_OF_LOGS	back to summary
private static final UnivariateStatistic SUM_OF_LOGS sumLog

SUM_OF_SQUARES	back to summary
private static final UnivariateStatistic SUM_OF_SQUARES sumSq

VARIANCE	back to summary
private static final Variance VARIANCE variance

StatUtils	back to summary
private StatUtils() Private Constructor

Method Detail

geometricMean back to summary

geometricMean	back to summary
public static double geometricMean(final double[] values) throws MathIllegalArgumentException Returns the geometric mean of the entries in the input array, or `Double.NaN` if the array is empty. Throws `IllegalArgumentException` if the array is null. See `org.apache.commons.math3.stat.descriptive.moment.GeometricMean` for details on the computing algorithm. Parameters values:double[] the input array Returns:double the geometric mean of the values or Double.NaN if the array is empty Exceptions MathIllegalArgumentException: if the array is null

public static double geometricMean(final double[] values) throws MathIllegalArgumentException

Returns the geometric mean of the entries in the input array, or Double.NaN if the array is empty.

Throws IllegalArgumentException if the array is null.

See org.apache.commons.math3.stat.descriptive.moment.GeometricMean for details on the computing algorithm.

Parameters

values:double[]: the input array

Returns:double

the geometric mean of the values or Double.NaN if the array is empty

Exceptions

MathIllegalArgumentException:: if the array is null

geometricMean back to summary

geometricMean	back to summary
public static double geometricMean(final double[] values, final int begin, final int length) throws MathIllegalArgumentException Returns the geometric mean of the entries in the specified portion of the input array, or `Double.NaN` if the designated subarray is empty. Throws `IllegalArgumentException` if the array is null. See `org.apache.commons.math3.stat.descriptive.moment.GeometricMean` for details on the computing algorithm. Parameters values:double[] the input array begin:int index of the first array element to include length:int the number of elements to include Returns:double the geometric mean of the values or Double.NaN if length = 0 Exceptions MathIllegalArgumentException: if the array is null or the array index parameters are not valid

public static double geometricMean(final double[] values, final int begin, final int length) throws MathIllegalArgumentException

Returns the geometric mean of the entries in the specified portion of the input array, or Double.NaN if the designated subarray is empty.

Throws IllegalArgumentException if the array is null.

See org.apache.commons.math3.stat.descriptive.moment.GeometricMean for details on the computing algorithm.

Parameters

values:double[]: the input array
begin:int: index of the first array element to include
length:int: the number of elements to include

Returns:double

the geometric mean of the values or Double.NaN if length = 0

Exceptions

MathIllegalArgumentException:: if the array is null or the array index parameters are not valid

getMode	back to summary
private static double[] getMode(double[] values, final int begin, final int length) Private helper method. Assumes parameters have been validated. Parameters values:double[] input data begin:int index (0-based) of the first array element to include length:int the number of elements to include Returns:double[] array of array of the most frequently occurring element(s) sorted in ascending order.

getMode

back to summary

private static double[] getMode(double[] values, final int begin, final int length)

Private helper method. Assumes parameters have been validated.

Parameters

values:double[]: input data
begin:int: index (0-based) of the first array element to include
length:int: the number of elements to include

Returns:double[]

array of array of the most frequently occurring element(s) sorted in ascending order.

max back to summary

max	back to summary
public static double max(final double[] values) throws MathIllegalArgumentException Returns the maximum of the entries in the input array, or `Double.NaN` if the array is empty. Throws `MathIllegalArgumentException` if the array is null. The result is `NaN` iff all values are `NaN` (i.e. `NaN` values have no impact on the value of the statistic). If any of the values equals `Double.POSITIVE_INFINITY`, the result is `Double.POSITIVE_INFINITY.` Parameters values:double[] the input array Returns:double the maximum of the values or Double.NaN if the array is empty Exceptions MathIllegalArgumentException: if the array is null

public static double max(final double[] values) throws MathIllegalArgumentException

Returns the maximum of the entries in the input array, or Double.NaN if the array is empty.

Throws MathIllegalArgumentException if the array is null.

The result is NaN iff all values are NaN (i.e. NaN values have no impact on the value of the statistic).
If any of the values equals Double.POSITIVE_INFINITY, the result is Double.POSITIVE_INFINITY.

Parameters

values:double[]: the input array

Returns:double

the maximum of the values or Double.NaN if the array is empty

Exceptions

MathIllegalArgumentException:: if the array is null

max back to summary

max	back to summary
public static double max(final double[] values, final int begin, final int length) throws MathIllegalArgumentException Returns the maximum of the entries in the specified portion of the input array, or `Double.NaN` if the designated subarray is empty. Throws `MathIllegalArgumentException` if the array is null or the array index parameters are not valid. The result is `NaN` iff all values are `NaN` (i.e. `NaN` values have no impact on the value of the statistic). If any of the values equals `Double.POSITIVE_INFINITY`, the result is `Double.POSITIVE_INFINITY.` Parameters values:double[] the input array begin:int index of the first array element to include length:int the number of elements to include Returns:double the maximum of the values or Double.NaN if length = 0 Exceptions MathIllegalArgumentException: if the array is null or the array index parameters are not valid

public static double max(final double[] values, final int begin, final int length) throws MathIllegalArgumentException

Returns the maximum of the entries in the specified portion of the input array, or Double.NaN if the designated subarray is empty.

Throws MathIllegalArgumentException if the array is null or the array index parameters are not valid.

The result is NaN iff all values are NaN (i.e. NaN values have no impact on the value of the statistic).
If any of the values equals Double.POSITIVE_INFINITY, the result is Double.POSITIVE_INFINITY.

Parameters

values:double[]: the input array
begin:int: index of the first array element to include
length:int: the number of elements to include

Returns:double

the maximum of the values or Double.NaN if length = 0

Exceptions

MathIllegalArgumentException:: if the array is null or the array index parameters are not valid

mean back to summary

mean	back to summary
public static double mean(final double[] values) throws MathIllegalArgumentException Returns the arithmetic mean of the entries in the input array, or `Double.NaN` if the array is empty. Throws `IllegalArgumentException` if the array is null. See `org.apache.commons.math3.stat.descriptive.moment.Mean` for details on the computing algorithm. Parameters values:double[] the input array Returns:double the mean of the values or Double.NaN if the array is empty Exceptions MathIllegalArgumentException: if the array is null

public static double mean(final double[] values) throws MathIllegalArgumentException

Returns the arithmetic mean of the entries in the input array, or Double.NaN if the array is empty.

Throws IllegalArgumentException if the array is null.

See org.apache.commons.math3.stat.descriptive.moment.Mean for details on the computing algorithm.

Parameters

values:double[]: the input array

Returns:double

the mean of the values or Double.NaN if the array is empty

Exceptions

MathIllegalArgumentException:: if the array is null

mean back to summary

mean	back to summary
public static double mean(final double[] values, final int begin, final int length) throws MathIllegalArgumentException Returns the arithmetic mean of the entries in the specified portion of the input array, or `Double.NaN` if the designated subarray is empty. Throws `IllegalArgumentException` if the array is null. See `org.apache.commons.math3.stat.descriptive.moment.Mean` for details on the computing algorithm. Parameters values:double[] the input array begin:int index of the first array element to include length:int the number of elements to include Returns:double the mean of the values or Double.NaN if length = 0 Exceptions MathIllegalArgumentException: if the array is null or the array index parameters are not valid

public static double mean(final double[] values, final int begin, final int length) throws MathIllegalArgumentException

Returns the arithmetic mean of the entries in the specified portion of the input array, or Double.NaN if the designated subarray is empty.

Throws IllegalArgumentException if the array is null.

See org.apache.commons.math3.stat.descriptive.moment.Mean for details on the computing algorithm.

Parameters

values:double[]: the input array
begin:int: index of the first array element to include
length:int: the number of elements to include

Returns:double

the mean of the values or Double.NaN if length = 0

Exceptions

MathIllegalArgumentException:: if the array is null or the array index parameters are not valid

meanDifference	back to summary
public static double meanDifference(final double[] sample1, final double[] sample2) throws DimensionMismatchException, NoDataException Returns the mean of the (signed) differences between corresponding elements of the input arrays -- i.e., sum(sample1[i] - sample2[i]) / sample1.length. Parameters sample1:double[] the first array sample2:double[] the second array Returns:double mean of paired differences Exceptions DimensionMismatchException: if the arrays do not have the same (positive) length. NoDataException: if the sample arrays are empty.

meanDifference

back to summary

public static double meanDifference(final double[] sample1, final double[] sample2) throws DimensionMismatchException, NoDataException

Returns the mean of the (signed) differences between corresponding elements of the input arrays -- i.e., sum(sample1[i] - sample2[i]) / sample1.length.

Parameters

sample1:double[]: the first array
sample2:double[]: the second array

Returns:double

mean of paired differences

Exceptions

DimensionMismatchException:: if the arrays do not have the same (positive) length.
NoDataException:: if the sample arrays are empty.

min back to summary

min	back to summary
public static double min(final double[] values) throws MathIllegalArgumentException Returns the minimum of the entries in the input array, or `Double.NaN` if the array is empty. Throws `MathIllegalArgumentException` if the array is null. The result is `NaN` iff all values are `NaN` (i.e. `NaN` values have no impact on the value of the statistic). If any of the values equals `Double.NEGATIVE_INFINITY`, the result is `Double.NEGATIVE_INFINITY.` Parameters values:double[] the input array Returns:double the minimum of the values or Double.NaN if the array is empty Exceptions MathIllegalArgumentException: if the array is null

public static double min(final double[] values) throws MathIllegalArgumentException

Returns the minimum of the entries in the input array, or Double.NaN if the array is empty.

Throws MathIllegalArgumentException if the array is null.

The result is NaN iff all values are NaN (i.e. NaN values have no impact on the value of the statistic).
If any of the values equals Double.NEGATIVE_INFINITY, the result is Double.NEGATIVE_INFINITY.

Parameters

values:double[]: the input array

Returns:double

the minimum of the values or Double.NaN if the array is empty

Exceptions

MathIllegalArgumentException:: if the array is null

min back to summary

min	back to summary
public static double min(final double[] values, final int begin, final int length) throws MathIllegalArgumentException Returns the minimum of the entries in the specified portion of the input array, or `Double.NaN` if the designated subarray is empty. Throws `MathIllegalArgumentException` if the array is null or the array index parameters are not valid. The result is `NaN` iff all values are `NaN` (i.e. `NaN` values have no impact on the value of the statistic). If any of the values equals `Double.NEGATIVE_INFINITY`, the result is `Double.NEGATIVE_INFINITY.` Parameters values:double[] the input array begin:int index of the first array element to include length:int the number of elements to include Returns:double the minimum of the values or Double.NaN if length = 0 Exceptions MathIllegalArgumentException: if the array is null or the array index parameters are not valid

public static double min(final double[] values, final int begin, final int length) throws MathIllegalArgumentException

Returns the minimum of the entries in the specified portion of the input array, or Double.NaN if the designated subarray is empty.

Throws MathIllegalArgumentException if the array is null or the array index parameters are not valid.

The result is NaN iff all values are NaN (i.e. NaN values have no impact on the value of the statistic).
If any of the values equals Double.NEGATIVE_INFINITY, the result is Double.NEGATIVE_INFINITY.

Parameters

values:double[]: the input array
begin:int: index of the first array element to include
length:int: the number of elements to include

Returns:double

the minimum of the values or Double.NaN if length = 0

Exceptions

MathIllegalArgumentException:: if the array is null or the array index parameters are not valid

mode back to summary

mode	back to summary
public static double[] mode(double[] sample) throws MathIllegalArgumentException Returns the sample mode(s). The mode is the most frequently occurring value in the sample. If there is a unique value with maximum frequency, this value is returned as the only element of the output array. Otherwise, the returned array contains the maximum frequency elements in increasing order. For example, if `sample` is {0, 12, 5, 6, 0, 13, 5, 17}, the returned array will have length two, with 0 in the first element and 5 in the second. NaN values are ignored when computing the mode - i.e., NaNs will never appear in the output array. If the sample includes only NaNs or has length 0, an empty array is returned. Parameters sample:double[] input data Returns:double[] array of array of the most frequently occurring element(s) sorted in ascending order. Exceptions MathIllegalArgumentException: if the indices are invalid or the array is null Since 3.3

public static double[] mode(double[] sample) throws MathIllegalArgumentException

Returns the sample mode(s). The mode is the most frequently occurring value in the sample. If there is a unique value with maximum frequency, this value is returned as the only element of the output array. Otherwise, the returned array contains the maximum frequency elements in increasing order. For example, if sample is {0, 12, 5, 6, 0, 13, 5, 17}, the returned array will have length two, with 0 in the first element and 5 in the second.

NaN values are ignored when computing the mode - i.e., NaNs will never appear in the output array. If the sample includes only NaNs or has length 0, an empty array is returned.

Parameters

sample:double[]: input data

Returns:double[]

array of array of the most frequently occurring element(s) sorted in ascending order.

Exceptions

MathIllegalArgumentException:: if the indices are invalid or the array is null

Since

3.3

mode back to summary

mode	back to summary
public static double[] mode(double[] sample, final int begin, final int length) Returns the sample mode(s). The mode is the most frequently occurring value in the sample. If there is a unique value with maximum frequency, this value is returned as the only element of the output array. Otherwise, the returned array contains the maximum frequency elements in increasing order. For example, if `sample` is {0, 12, 5, 6, 0, 13, 5, 17}, the returned array will have length two, with 0 in the first element and 5 in the second. NaN values are ignored when computing the mode - i.e., NaNs will never appear in the output array. If the sample includes only NaNs or has length 0, an empty array is returned. Parameters sample:double[] input data begin:int index (0-based) of the first array element to include length:int the number of elements to include Returns:double[] array of array of the most frequently occurring element(s) sorted in ascending order. Exceptions MathIllegalArgumentException: if the indices are invalid or the array is null Since 3.3

public static double[] mode(double[] sample, final int begin, final int length)

NaN values are ignored when computing the mode - i.e., NaNs will never appear in the output array. If the sample includes only NaNs or has length 0, an empty array is returned.

Parameters

sample:double[]: input data
begin:int: index (0-based) of the first array element to include
length:int: the number of elements to include

Returns:double[]

array of array of the most frequently occurring element(s) sorted in ascending order.

Exceptions

MathIllegalArgumentException:: if the indices are invalid or the array is null

Since

3.3

normalize	back to summary
public static double[] normalize(final double[] sample) Normalize (standardize) the sample, so it is has a mean of 0 and a standard deviation of 1. Parameters sample:double[] Sample to normalize. Returns:double[] normalized (standardized) sample. Since 2.2

normalize

back to summary

public static double[] normalize(final double[] sample)

Normalize (standardize) the sample, so it is has a mean of 0 and a standard deviation of 1.

Parameters

sample:double[]: Sample to normalize.

Returns:double[]

normalized (standardized) sample.

Since

2.2

percentile back to summary

percentile	back to summary
public static double percentile(final double[] values, final double p) throws MathIllegalArgumentException Returns an estimate of the `p`th percentile of the values in the `values` array. Returns `Double.NaN` if `values` has length `0` Returns (for any value of `p`) `values[0]` if `values` has length `1` Throws `IllegalArgumentException` if `values` is null or p is not a valid quantile value (p must be greater than 0 and less than or equal to 100) See `org.apache.commons.math3.stat.descriptive.rank.Percentile` for a description of the percentile estimation algorithm used. Parameters values:double[] input array of values p:double the percentile value to compute Returns:double the percentile value or Double.NaN if the array is empty Exceptions MathIllegalArgumentException: if `values` is null or p is invalid

public static double percentile(final double[] values, final double p) throws MathIllegalArgumentException

Returns an estimate of the pth percentile of the values in the values array.

Returns Double.NaN if values has length 0

Returns (for any value of p) values[0] if values has length 1
Throws IllegalArgumentException if values is null or p is not a valid quantile value (p must be greater than 0 and less than or equal to 100)

See org.apache.commons.math3.stat.descriptive.rank.Percentile for a description of the percentile estimation algorithm used.

Parameters

values:double[]: input array of values
p:double: the percentile value to compute

Returns:double

the percentile value or Double.NaN if the array is empty

Exceptions

MathIllegalArgumentException:: if values is null or p is invalid

percentile back to summary

percentile	back to summary
public static double percentile(final double[] values, final int begin, final int length, final double p) throws MathIllegalArgumentException Returns an estimate of the `p`th percentile of the values in the `values` array, starting with the element in (0-based) position `begin` in the array and including `length` values. Returns `Double.NaN` if `length = 0` Returns (for any value of `p`) `values[begin]` if `length = 1` Throws `MathIllegalArgumentException` if `values` is null , `begin` or `length` is invalid, or `p` is not a valid quantile value (p must be greater than 0 and less than or equal to 100) See `org.apache.commons.math3.stat.descriptive.rank.Percentile` for a description of the percentile estimation algorithm used. Parameters values:double[] array of input values begin:int the first (0-based) element to include in the computation length:int the number of array elements to include p:double the percentile to compute Returns:double the percentile value Exceptions MathIllegalArgumentException: if the parameters are not valid or the input array is null

public static double percentile(final double[] values, final int begin, final int length, final double p) throws MathIllegalArgumentException

Returns an estimate of the pth percentile of the values in the values array, starting with the element in (0-based) position begin in the array and including length values.

Returns Double.NaN if length = 0
Returns (for any value of p) values[begin] if length = 1
Throws MathIllegalArgumentException if values is null , begin or length is invalid, or p is not a valid quantile value (p must be greater than 0 and less than or equal to 100)

See org.apache.commons.math3.stat.descriptive.rank.Percentile for a description of the percentile estimation algorithm used.

Parameters

values:double[]: array of input values
begin:int: the first (0-based) element to include in the computation
length:int: the number of array elements to include
p:double: the percentile to compute

Returns:double

the percentile value

Exceptions

MathIllegalArgumentException:: if the parameters are not valid or the input array is null

populationVariance back to summary

populationVariance	back to summary
public static double populationVariance(final double[] values) throws MathIllegalArgumentException Returns the population variance of the entries in the input array, or `Double.NaN` if the array is empty. See `org.apache.commons.math3.stat.descriptive.moment.Variance` for details on the formula and computing algorithm. Returns 0 for a single-value (i.e. length = 1) sample. Throws `MathIllegalArgumentException` if the array is null. Parameters values:double[] the input array Returns:double the population variance of the values or Double.NaN if the array is empty Exceptions MathIllegalArgumentException: if the array is null

public static double populationVariance(final double[] values) throws MathIllegalArgumentException

Returns the population variance of the entries in the input array, or Double.NaN if the array is empty.

See org.apache.commons.math3.stat.descriptive.moment.Variance for details on the formula and computing algorithm.

Returns 0 for a single-value (i.e. length = 1) sample.

Throws MathIllegalArgumentException if the array is null.

Parameters

values:double[]: the input array

Returns:double

the population variance of the values or Double.NaN if the array is empty

Exceptions

MathIllegalArgumentException:: if the array is null

populationVariance back to summary

populationVariance	back to summary
public static double populationVariance(final double[] values, final int begin, final int length) throws MathIllegalArgumentException Returns the population variance of the entries in the specified portion of the input array, or `Double.NaN` if the designated subarray is empty. See `org.apache.commons.math3.stat.descriptive.moment.Variance` for details on the computing algorithm. Returns 0 for a single-value (i.e. length = 1) sample. Throws `MathIllegalArgumentException` if the array is null or the array index parameters are not valid. Parameters values:double[] the input array begin:int index of the first array element to include length:int the number of elements to include Returns:double the population variance of the values or Double.NaN if length = 0 Exceptions MathIllegalArgumentException: if the array is null or the array index parameters are not valid

public static double populationVariance(final double[] values, final int begin, final int length) throws MathIllegalArgumentException

Returns the population variance of the entries in the specified portion of the input array, or Double.NaN if the designated subarray is empty.

See org.apache.commons.math3.stat.descriptive.moment.Variance for details on the computing algorithm.

Returns 0 for a single-value (i.e. length = 1) sample.

Throws MathIllegalArgumentException if the array is null or the array index parameters are not valid.

Parameters

values:double[]: the input array
begin:int: index of the first array element to include
length:int: the number of elements to include

Returns:double

the population variance of the values or Double.NaN if length = 0

Exceptions

MathIllegalArgumentException:: if the array is null or the array index parameters are not valid

populationVariance back to summary

populationVariance	back to summary
public static double populationVariance(final double[] values, final double mean, final int begin, final int length) throws MathIllegalArgumentException Returns the population variance of the entries in the specified portion of the input array, using the precomputed mean value. Returns `Double.NaN` if the designated subarray is empty. See `org.apache.commons.math3.stat.descriptive.moment.Variance` for details on the computing algorithm. The formula used assumes that the supplied mean value is the arithmetic mean of the sample data, not a known population parameter. This method is supplied only to save computation when the mean has already been computed. Returns 0 for a single-value (i.e. length = 1) sample. Throws `MathIllegalArgumentException` if the array is null or the array index parameters are not valid. Parameters values:double[] the input array mean:double the precomputed mean value begin:int index of the first array element to include length:int the number of elements to include Returns:double the population variance of the values or Double.NaN if length = 0 Exceptions MathIllegalArgumentException: if the array is null or the array index parameters are not valid

public static double populationVariance(final double[] values, final double mean, final int begin, final int length) throws MathIllegalArgumentException

Returns the population variance of the entries in the specified portion of the input array, using the precomputed mean value. Returns Double.NaN if the designated subarray is empty.

See org.apache.commons.math3.stat.descriptive.moment.Variance for details on the computing algorithm.

The formula used assumes that the supplied mean value is the arithmetic mean of the sample data, not a known population parameter. This method is supplied only to save computation when the mean has already been computed.

Returns 0 for a single-value (i.e. length = 1) sample.

Throws MathIllegalArgumentException if the array is null or the array index parameters are not valid.

Parameters

values:double[]: the input array
mean:double: the precomputed mean value
begin:int: index of the first array element to include
length:int: the number of elements to include

Returns:double

the population variance of the values or Double.NaN if length = 0

Exceptions

MathIllegalArgumentException:: if the array is null or the array index parameters are not valid

populationVariance back to summary

populationVariance	back to summary
public static double populationVariance(final double[] values, final double mean) throws MathIllegalArgumentException Returns the population variance of the entries in the input array, using the precomputed mean value. Returns `Double.NaN` if the array is empty. See `org.apache.commons.math3.stat.descriptive.moment.Variance` for details on the computing algorithm. The formula used assumes that the supplied mean value is the arithmetic mean of the sample data, not a known population parameter. This method is supplied only to save computation when the mean has already been computed. Returns 0 for a single-value (i.e. length = 1) sample. Throws `MathIllegalArgumentException` if the array is null. Parameters values:double[] the input array mean:double the precomputed mean value Returns:double the population variance of the values or Double.NaN if the array is empty Exceptions MathIllegalArgumentException: if the array is null

public static double populationVariance(final double[] values, final double mean) throws MathIllegalArgumentException

Returns the population variance of the entries in the input array, using the precomputed mean value. Returns Double.NaN if the array is empty.

See org.apache.commons.math3.stat.descriptive.moment.Variance for details on the computing algorithm.

Returns 0 for a single-value (i.e. length = 1) sample.

Throws MathIllegalArgumentException if the array is null.

Parameters

values:double[]: the input array
mean:double: the precomputed mean value

Returns:double

the population variance of the values or Double.NaN if the array is empty

Exceptions

MathIllegalArgumentException:: if the array is null

product back to summary

product	back to summary
public static double product(final double[] values) throws MathIllegalArgumentException Returns the product of the entries in the input array, or `Double.NaN` if the array is empty. Throws `IllegalArgumentException` if the array is null. Parameters values:double[] the input array Returns:double the product of the values or Double.NaN if the array is empty Exceptions MathIllegalArgumentException: if the array is null

public static double product(final double[] values) throws MathIllegalArgumentException

Returns the product of the entries in the input array, or Double.NaN if the array is empty.

Throws IllegalArgumentException if the array is null.

Parameters

values:double[]: the input array

Returns:double

the product of the values or Double.NaN if the array is empty

Exceptions

MathIllegalArgumentException:: if the array is null

product back to summary

product	back to summary
public static double product(final double[] values, final int begin, final int length) throws MathIllegalArgumentException Returns the product of the entries in the specified portion of the input array, or `Double.NaN` if the designated subarray is empty. Throws `IllegalArgumentException` if the array is null. Parameters values:double[] the input array begin:int index of the first array element to include length:int the number of elements to include Returns:double the product of the values or Double.NaN if length = 0 Exceptions MathIllegalArgumentException: if the array is null or the array index parameters are not valid

public static double product(final double[] values, final int begin, final int length) throws MathIllegalArgumentException

Returns the product of the entries in the specified portion of the input array, or Double.NaN if the designated subarray is empty.

Throws IllegalArgumentException if the array is null.

Parameters

values:double[]: the input array
begin:int: index of the first array element to include
length:int: the number of elements to include

Returns:double

the product of the values or Double.NaN if length = 0

Exceptions

MathIllegalArgumentException:: if the array is null or the array index parameters are not valid

sum back to summary

sum	back to summary
public static double sum(final double[] values) throws MathIllegalArgumentException Returns the sum of the values in the input array, or `Double.NaN` if the array is empty. Throws `IllegalArgumentException` if the input array is null. Parameters values:double[] array of values to sum Returns:double the sum of the values or `Double.NaN` if the array is empty Exceptions MathIllegalArgumentException: if the array is null

public static double sum(final double[] values) throws MathIllegalArgumentException

Returns the sum of the values in the input array, or Double.NaN if the array is empty.

Throws IllegalArgumentException if the input array is null.

Parameters

values:double[]: array of values to sum

Returns:double

the sum of the values or Double.NaN if the array is empty

Exceptions

MathIllegalArgumentException:: if the array is null

sum back to summary

sum	back to summary
public static double sum(final double[] values, final int begin, final int length) throws MathIllegalArgumentException Returns the sum of the entries in the specified portion of the input array, or `Double.NaN` if the designated subarray is empty. Throws `IllegalArgumentException` if the array is null. Parameters values:double[] the input array begin:int index of the first array element to include length:int the number of elements to include Returns:double the sum of the values or Double.NaN if length = 0 Exceptions MathIllegalArgumentException: if the array is null or the array index parameters are not valid

public static double sum(final double[] values, final int begin, final int length) throws MathIllegalArgumentException

Returns the sum of the entries in the specified portion of the input array, or Double.NaN if the designated subarray is empty.

Throws IllegalArgumentException if the array is null.

Parameters

values:double[]: the input array
begin:int: index of the first array element to include
length:int: the number of elements to include

Returns:double

the sum of the values or Double.NaN if length = 0

Exceptions

MathIllegalArgumentException:: if the array is null or the array index parameters are not valid

sumDifference	back to summary
public static double sumDifference(final double[] sample1, final double[] sample2) throws DimensionMismatchException, NoDataException Returns the sum of the (signed) differences between corresponding elements of the input arrays -- i.e., sum(sample1[i] - sample2[i]). Parameters sample1:double[] the first array sample2:double[] the second array Returns:double sum of paired differences Exceptions DimensionMismatchException: if the arrays do not have the same (positive) length. NoDataException: if the sample arrays are empty.

sumDifference

back to summary

public static double sumDifference(final double[] sample1, final double[] sample2) throws DimensionMismatchException, NoDataException

Returns the sum of the (signed) differences between corresponding elements of the input arrays -- i.e., sum(sample1[i] - sample2[i]).

Parameters

sample1:double[]: the first array
sample2:double[]: the second array

Returns:double

sum of paired differences

Exceptions

DimensionMismatchException:: if the arrays do not have the same (positive) length.
NoDataException:: if the sample arrays are empty.

sumLog back to summary

sumLog	back to summary
public static double sumLog(final double[] values) throws MathIllegalArgumentException Returns the sum of the natural logs of the entries in the input array, or `Double.NaN` if the array is empty. Throws `IllegalArgumentException` if the array is null. See `org.apache.commons.math3.stat.descriptive.summary.SumOfLogs`. Parameters values:double[] the input array Returns:double the sum of the natural logs of the values or Double.NaN if the array is empty Exceptions MathIllegalArgumentException: if the array is null

public static double sumLog(final double[] values) throws MathIllegalArgumentException

Returns the sum of the natural logs of the entries in the input array, or Double.NaN if the array is empty.

Throws IllegalArgumentException if the array is null.

See org.apache.commons.math3.stat.descriptive.summary.SumOfLogs.

Parameters

values:double[]: the input array

Returns:double

the sum of the natural logs of the values or Double.NaN if the array is empty

Exceptions

MathIllegalArgumentException:: if the array is null

sumLog back to summary

sumLog	back to summary
public static double sumLog(final double[] values, final int begin, final int length) throws MathIllegalArgumentException Returns the sum of the natural logs of the entries in the specified portion of the input array, or `Double.NaN` if the designated subarray is empty. Throws `IllegalArgumentException` if the array is null. See `org.apache.commons.math3.stat.descriptive.summary.SumOfLogs`. Parameters values:double[] the input array begin:int index of the first array element to include length:int the number of elements to include Returns:double the sum of the natural logs of the values or Double.NaN if length = 0 Exceptions MathIllegalArgumentException: if the array is null or the array index parameters are not valid

public static double sumLog(final double[] values, final int begin, final int length) throws MathIllegalArgumentException

Returns the sum of the natural logs of the entries in the specified portion of the input array, or Double.NaN if the designated subarray is empty.

Throws IllegalArgumentException if the array is null.

See org.apache.commons.math3.stat.descriptive.summary.SumOfLogs.

Parameters

values:double[]: the input array
begin:int: index of the first array element to include
length:int: the number of elements to include

Returns:double

the sum of the natural logs of the values or Double.NaN if length = 0

Exceptions

MathIllegalArgumentException:: if the array is null or the array index parameters are not valid

sumSq back to summary

sumSq	back to summary
public static double sumSq(final double[] values) throws MathIllegalArgumentException Returns the sum of the squares of the entries in the input array, or `Double.NaN` if the array is empty. Throws `IllegalArgumentException` if the array is null. Parameters values:double[] input array Returns:double the sum of the squared values or `Double.NaN` if the array is empty Exceptions MathIllegalArgumentException: if the array is null

public static double sumSq(final double[] values) throws MathIllegalArgumentException

Returns the sum of the squares of the entries in the input array, or Double.NaN if the array is empty.

Throws IllegalArgumentException if the array is null.

Parameters

values:double[]: input array

Returns:double

the sum of the squared values or Double.NaN if the array is empty

Exceptions

MathIllegalArgumentException:: if the array is null

sumSq back to summary

sumSq	back to summary
public static double sumSq(final double[] values, final int begin, final int length) throws MathIllegalArgumentException Returns the sum of the squares of the entries in the specified portion of the input array, or `Double.NaN` if the designated subarray is empty. Throws `IllegalArgumentException` if the array is null. Parameters values:double[] the input array begin:int index of the first array element to include length:int the number of elements to include Returns:double the sum of the squares of the values or Double.NaN if length = 0 Exceptions MathIllegalArgumentException: if the array is null or the array index parameters are not valid

public static double sumSq(final double[] values, final int begin, final int length) throws MathIllegalArgumentException

Returns the sum of the squares of the entries in the specified portion of the input array, or Double.NaN if the designated subarray is empty.

Throws IllegalArgumentException if the array is null.

Parameters

values:double[]: the input array
begin:int: index of the first array element to include
length:int: the number of elements to include

Returns:double

the sum of the squares of the values or Double.NaN if length = 0

Exceptions

MathIllegalArgumentException:: if the array is null or the array index parameters are not valid

variance back to summary

variance	back to summary
public static double variance(final double[] values) throws MathIllegalArgumentException Returns the variance of the entries in the input array, or `Double.NaN` if the array is empty. This method returns the bias-corrected sample variance (using `n - 1` in the denominator). Use `populationVariance(double[])` for the non-bias-corrected population variance. See `org.apache.commons.math3.stat.descriptive.moment.Variance` for details on the computing algorithm. Returns 0 for a single-value (i.e. length = 1) sample. Throws `MathIllegalArgumentException` if the array is null. Parameters values:double[] the input array Returns:double the variance of the values or Double.NaN if the array is empty Exceptions MathIllegalArgumentException: if the array is null

public static double variance(final double[] values) throws MathIllegalArgumentException

Returns the variance of the entries in the input array, or Double.NaN if the array is empty.

This method returns the bias-corrected sample variance (using n - 1 in the denominator). Use populationVariance(double[]) for the non-bias-corrected population variance.

See org.apache.commons.math3.stat.descriptive.moment.Variance for details on the computing algorithm.

Returns 0 for a single-value (i.e. length = 1) sample.

Throws MathIllegalArgumentException if the array is null.

Parameters

values:double[]: the input array

Returns:double

the variance of the values or Double.NaN if the array is empty

Exceptions

MathIllegalArgumentException:: if the array is null

variance back to summary

variance	back to summary
public static double variance(final double[] values, final int begin, final int length) throws MathIllegalArgumentException Returns the variance of the entries in the specified portion of the input array, or `Double.NaN` if the designated subarray is empty. This method returns the bias-corrected sample variance (using `n - 1` in the denominator). Use `populationVariance(double[], int, int)` for the non-bias-corrected population variance. See `org.apache.commons.math3.stat.descriptive.moment.Variance` for details on the computing algorithm. Returns 0 for a single-value (i.e. length = 1) sample. Throws `MathIllegalArgumentException` if the array is null or the array index parameters are not valid. Parameters values:double[] the input array begin:int index of the first array element to include length:int the number of elements to include Returns:double the variance of the values or Double.NaN if length = 0 Exceptions MathIllegalArgumentException: if the array is null or the array index parameters are not valid

public static double variance(final double[] values, final int begin, final int length) throws MathIllegalArgumentException

Returns the variance of the entries in the specified portion of the input array, or Double.NaN if the designated subarray is empty.

This method returns the bias-corrected sample variance (using n - 1 in the denominator). Use populationVariance(double[], int, int) for the non-bias-corrected population variance.

See org.apache.commons.math3.stat.descriptive.moment.Variance for details on the computing algorithm.

Returns 0 for a single-value (i.e. length = 1) sample.

Throws MathIllegalArgumentException if the array is null or the array index parameters are not valid.

Parameters

values:double[]: the input array
begin:int: index of the first array element to include
length:int: the number of elements to include

Returns:double

the variance of the values or Double.NaN if length = 0

Exceptions

MathIllegalArgumentException:: if the array is null or the array index parameters are not valid

variance back to summary

variance	back to summary
public static double variance(final double[] values, final double mean, final int begin, final int length) throws MathIllegalArgumentException Returns the variance of the entries in the specified portion of the input array, using the precomputed mean value. Returns `Double.NaN` if the designated subarray is empty. This method returns the bias-corrected sample variance (using `n - 1` in the denominator). Use `populationVariance(double[], double, int, int)` for the non-bias-corrected population variance. See `org.apache.commons.math3.stat.descriptive.moment.Variance` for details on the computing algorithm. The formula used assumes that the supplied mean value is the arithmetic mean of the sample data, not a known population parameter. This method is supplied only to save computation when the mean has already been computed. Returns 0 for a single-value (i.e. length = 1) sample. Throws `MathIllegalArgumentException` if the array is null or the array index parameters are not valid. Parameters values:double[] the input array mean:double the precomputed mean value begin:int index of the first array element to include length:int the number of elements to include Returns:double the variance of the values or Double.NaN if length = 0 Exceptions MathIllegalArgumentException: if the array is null or the array index parameters are not valid

public static double variance(final double[] values, final double mean, final int begin, final int length) throws MathIllegalArgumentException

Returns the variance of the entries in the specified portion of the input array, using the precomputed mean value. Returns Double.NaN if the designated subarray is empty.

This method returns the bias-corrected sample variance (using n - 1 in the denominator). Use populationVariance(double[], double, int, int) for the non-bias-corrected population variance.

See org.apache.commons.math3.stat.descriptive.moment.Variance for details on the computing algorithm.

Returns 0 for a single-value (i.e. length = 1) sample.

Throws MathIllegalArgumentException if the array is null or the array index parameters are not valid.

Parameters

values:double[]: the input array
mean:double: the precomputed mean value
begin:int: index of the first array element to include
length:int: the number of elements to include

Returns:double

the variance of the values or Double.NaN if length = 0

Exceptions

MathIllegalArgumentException:: if the array is null or the array index parameters are not valid

variance back to summary

variance	back to summary
public static double variance(final double[] values, final double mean) throws MathIllegalArgumentException Returns the variance of the entries in the input array, using the precomputed mean value. Returns `Double.NaN` if the array is empty. This method returns the bias-corrected sample variance (using `n - 1` in the denominator). Use `populationVariance(double[], double)` for the non-bias-corrected population variance. See `org.apache.commons.math3.stat.descriptive.moment.Variance` for details on the computing algorithm. The formula used assumes that the supplied mean value is the arithmetic mean of the sample data, not a known population parameter. This method is supplied only to save computation when the mean has already been computed. Returns 0 for a single-value (i.e. length = 1) sample. Throws `MathIllegalArgumentException` if the array is null. Parameters values:double[] the input array mean:double the precomputed mean value Returns:double the variance of the values or Double.NaN if the array is empty Exceptions MathIllegalArgumentException: if the array is null

public static double variance(final double[] values, final double mean) throws MathIllegalArgumentException

Returns the variance of the entries in the input array, using the precomputed mean value. Returns Double.NaN if the array is empty.

This method returns the bias-corrected sample variance (using n - 1 in the denominator). Use populationVariance(double[], double) for the non-bias-corrected population variance.

See org.apache.commons.math3.stat.descriptive.moment.Variance for details on the computing algorithm.

Returns 0 for a single-value (i.e. length = 1) sample.

Throws MathIllegalArgumentException if the array is null.

Parameters

values:double[]: the input array
mean:double: the precomputed mean value

Returns:double

the variance of the values or Double.NaN if the array is empty

Exceptions

MathIllegalArgumentException:: if the array is null

varianceDifference back to summary

varianceDifference	back to summary
public static double varianceDifference(final double[] sample1, final double[] sample2, double meanDifference) throws DimensionMismatchException, NumberIsTooSmallException Returns the variance of the (signed) differences between corresponding elements of the input arrays -- i.e., var(sample1[i] - sample2[i]). Parameters sample1:double[] the first array sample2:double[] the second array meanDifference:double the mean difference between corresponding entries Returns:double variance of paired differences Exceptions DimensionMismatchException: if the arrays do not have the same length. NumberIsTooSmallException: if the arrays length is less than 2. See Also `meanDifference(double[], double[])`

public static double varianceDifference(final double[] sample1, final double[] sample2, double meanDifference) throws DimensionMismatchException, NumberIsTooSmallException

Returns the variance of the (signed) differences between corresponding elements of the input arrays -- i.e., var(sample1[i] - sample2[i]).

Parameters

sample1:double[]: the first array
sample2:double[]: the second array
meanDifference:double: the mean difference between corresponding entries

Returns:double

variance of paired differences

Exceptions

DimensionMismatchException:: if the arrays do not have the same length.
NumberIsTooSmallException:: if the arrays length is less than 2.

See Also

meanDifference(double[], double[])

public final Class StatUtils

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