Utilities for calculating basic statistics. More...

Static Public Member Functions
static double	sum (double[] numbers)
	Returns the sum number in the numbers list. More...

static double	mean (double[] numbers)
	Returns the mean number in the numbers list. More...

static double	min (double[] numbers)
	Returns the minimum value among the numbers . More...

static double	max (double[] numbers)
	Returns the maximum value among the numbers . More...

static double	stddev (double[] numbers, boolean biasCorrected)
	Returns the standard deviation of the numbers. More...

static double	var (double[] numbers, boolean biasCorrected)
	Computes the variance of the available values. More...

static double	median (double[] m)
	Calculates median value of a sorted list. More...

static double	kurtosis (double[] m, boolean biasCorrected)
	Computes the Kurtosis of the available values. More...

static double	skewness (double[] m, boolean biasCorrected)
	Computes the skewness of the available values. More...

Detailed Description

Utilities for calculating basic statistics.

Author: Vishwesh Venkatraman

Definition at line 25 of file StatUtils.java.

Member Function Documentation

◆ kurtosis()

static double denoptim.utils.StatUtils.kurtosis	(	double[]	m,
		boolean	biasCorrected
	)

static

Computes the Kurtosis of the available values.

We use the following (unbiased) formula to define kurtosis:

kurtosis = { [n(n+1) / (n -1)(n - 2)(n-3)] sum[(x_i - mean)^4] / std^4 } - [3(n-1)^2 / (n-2)(n-3)]

where n is the number of values, mean is the Mean and std is the StandardDeviation

Note that this statistic is undefined for n < 4. Double.Nan is returned when there is not sufficient data to compute the statistic.

Definition at line 205 of file StatUtils.java.

References denoptim.utils.StatUtils.mean(), and denoptim.utils.StatUtils.var().

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◆ max()

static double denoptim.utils.StatUtils.max ( double[] numbers )

static

Returns the maximum value among the numbers .

Parameters

numbers list/array of numbers to calculate the max of.

Returns: the max number in the numbers list.

Definition at line 85 of file StatUtils.java.

References denoptim.utils.StatUtils.max().

Referenced by denoptim.ga.EAUtils.getSummaryStatistics(), and denoptim.utils.StatUtils.max().

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◆ mean()

static double denoptim.utils.StatUtils.mean ( double[] numbers )

static

Returns the mean number in the numbers list.

Parameters

numbers list/array of numbers to calculate the mean of.

Returns: the mean of the numbers.

Definition at line 53 of file StatUtils.java.

References denoptim.utils.StatUtils.sum().

Referenced by denoptim.ga.EAUtils.getSummaryStatistics(), denoptim.utils.StatUtils.kurtosis(), denoptim.utils.StatUtils.skewness(), and denoptim.utils.StatUtils.var().

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◆ median()

static double denoptim.utils.StatUtils.median ( double[] m )

static

Calculates median value of a sorted list.

Parameters

m

Returns: median value of m

Definition at line 172 of file StatUtils.java.

Referenced by denoptim.ga.EAUtils.getSummaryStatistics().

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◆ min()

static double denoptim.utils.StatUtils.min ( double[] numbers )

static

Returns the minimum value among the numbers .

Parameters

numbers list/array of numbers to calculate the mean of.

Returns: the min number in the numbers list.

Definition at line 67 of file StatUtils.java.

References denoptim.utils.StatUtils.min().

Referenced by denoptim.ga.EAUtils.getSummaryStatistics(), and denoptim.utils.StatUtils.min().

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◆ skewness()

static double denoptim.utils.StatUtils.skewness	(	double[]	m,
		boolean	biasCorrected
	)

static

Computes the skewness of the available values.

Parameters

m	sample
biasCorrected	biasCorrected true if variance is calculated by dividing by n - 1. False if by n. stddev is a sqrt of the variance.

Returns: skewness of sample or NaN if sample size is strictly less than 4.

Definition at line 246 of file StatUtils.java.

References denoptim.utils.StatUtils.mean(), and denoptim.utils.StatUtils.stddev().

Referenced by denoptim.ga.EAUtils.getSummaryStatistics().

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◆ stddev()

static double denoptim.utils.StatUtils.stddev	(	double[]	numbers,
		boolean	biasCorrected
	)

static

Returns the standard deviation of the numbers.

Double.NaN is returned if the numbers list is empty.

Parameters

numbers	the numbers to calculate the standard deviation.
biasCorrected	true if variance is calculated by dividing by n - 1. False if by n. stddev is a sqrt of the variance.

Returns: the standard deviation

Definition at line 107 of file StatUtils.java.

References denoptim.utils.StatUtils.stddev(), and denoptim.utils.StatUtils.var().

Referenced by denoptim.ga.EAUtils.getPopulationSD(), denoptim.ga.EAUtils.getSummaryStatistics(), denoptim.utils.StatUtils.skewness(), and denoptim.utils.StatUtils.stddev().

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◆ sum()

static double denoptim.utils.StatUtils.sum ( double[] numbers )

static

Returns the sum number in the numbers list.

Parameters

numbers list/array of numbers to calculate the sum of.

Returns: the sum of the numbers.

Definition at line 36 of file StatUtils.java.

References denoptim.utils.StatUtils.sum().

Referenced by denoptim.utils.StatUtils.mean(), denoptim.utils.StatUtils.sum(), and denoptim.utils.StatUtils.var().

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◆ var()

static double denoptim.utils.StatUtils.var	(	double[]	numbers,
		boolean	biasCorrected
	)

static

Computes the variance of the available values.

By default, the unbiased "sample variance" definitional formula is used: variance = sum((x_i - mean)^2) / (n - 1)

The "population variance" ( sum((x_i - mean)^2) / n ) can also be computed using this statistic. The biasCorrected property determines whether the "population" or "sample" value is returned by the evaluate and getResult methods. To compute population variances, set this property to false.

Parameters

numbers	the numbers to calculate the variance.
biasCorrected	true if variance is calculated by dividing by n - 1. False if by n.

Returns: the variance of the numbers.

Definition at line 145 of file StatUtils.java.

References denoptim.utils.StatUtils.mean(), and denoptim.utils.StatUtils.sum().

Referenced by denoptim.utils.StatUtils.kurtosis(), and denoptim.utils.StatUtils.stddev().

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The documentation for this class was generated from the following file:

/github/workspace/src/main/java/denoptim/utils/StatUtils.java

Static Public Member Functions

Detailed Description

Member Function Documentation

◆ kurtosis()

◆ max()

◆ mean()

◆ median()

◆ min()

◆ skewness()

◆ stddev()

◆ sum()

◆ var()