Statistics
public class Statistics : NSObject
The class that helps to process numerical data
Statistics
was designed to help with the mathematics of the collection, organization, and interpretation of numerical data, especially the analysis of population characteristics by inference from sampling.

The list used for statistical computations
Declaration
Swift
public var list: [BigNumber]

Creates a
Statistics
objectExample:
Statistics(1, 2, 3, 4, 5, 6, 7, 8, 9, 10)
Declaration
Swift
public init(_ list: Double...)
Parameters
list
A list of
Double
used for statistical computations

Return the arithmetic mean (average) of the list
The arithmetic mean of a set of values is the quantity commonly called “the” mean or the average. It’s simply the sum of all the terms in a list, divided by the number of elements in the list.
Declaration
Swift
var average: BigNumber { get }

Alias for average
Declaration
Swift
var mean: BigNumber { get }

Returns the average of the absolute deviations of data points from their mean. It is a measure of the variability in a data set.
Declaration
Swift
var MAD: BigDouble { get }

Returns the sum of squares of deviations of data points from their sample mean.
Declaration
Swift
var devSquared: BigDouble { get }

Returns the geometric mean.
In mathematics, the geometric mean is a mean or average, which indicates the central tendency or typical value of a set of numbers by using the product of their values (as opposed to the arithmetic mean which uses their sum). The geometric mean is defined as the nth root of the product of n numbers, i.e., for a set of numbers x_1, x_2, …, x_n, the geometric mean is defined as
\left(\prod_{i=1}^n x_i\right)^\frac{1}{n} = \sqrt[n]{x_1 x_2 \cdots x_n}Declaration
Swift
var geometricMean: BigDouble { get }

Returns the harmonic mean
In mathematics, the harmonic mean (sometimes called the subcontrary mean) is one of several kinds of average, and in particular, one of the Pythagorean means. Typically, it is appropriate for situations when the average of rates is desired.
The harmonic mean can be expressed as the reciprocal of the arithmetic mean of the reciprocals of the given set of observations. As a simple example, the harmonic mean of 1, 4, and 4 is
\left(\frac{1^{1} + 4^{1} + 4^{1}}{3}\right)^{1} = \frac{3}{\frac{1}{1} + \frac{1}{4} + \frac{1}{4}} = \frac{3}{1.5} = 2Declaration
Swift
var harmonicMean: BigDouble { get }

Return the weighted arithmetic mean (average) of the list with the given coefficients
The weighted arithmetic mean is similar to an ordinary arithmetic mean (the most common type of average), except that instead of each of the data points contributing equally to the final average, some data points contribute more than others. The notion of weighted mean plays a role in descriptive statistics and also occurs in a more general form in several other areas of mathematics.
If all the weights are equal, then the weighted mean is the same as the arithmetic mean. While weighted means generally behave in a similar fashion to arithmetic means, they do have a few counterintuitive properties, as captured for instance in Simpson’s paradox.
Parameters
coefficients
The weighted coefficients you want to use to multiply the original list.

This function returns the correlation coefficient of two cell ranges.
Use the correlation coefficient to determine the relationship between two properties. For example, you can examine the relationship between a location’s average temperature and the use of air conditioners.
Parameters
list
A second array to be compared with.

Returns the Fisher transformation at x. This transformation produces a function that is normally distributed rather than skewed. Use this function to perform hypothesis testing on the correlation coefficient.
Parameters
x
A numeric value for which you want the transformation.
Return Value
The Fisher transformation at x.

Returns the inverse of the Fisher transformation. Use this transformation when analyzing correlations between ranges or arrays of data. If y = fisher(x), then inverseFisher(y) = x.
Parameters
y
The image of x using the fisher transformation
Return Value
The inverse of the Fisher transformation.

In mathematics, the error function (also called the Gauss error function), often denoted by erf, is a complex function of a complex variable defined as:
\operatorname{erf} z = \frac{2}{\sqrt\pi}\int_0^z e^{t^2}\,dtParameters
x
Any number
Return Value
\operatorname{erf}(x)

Integral of the Gauss function
Computed using:
\int_{0}^{x}\frac{1}{\sqrt{2\pi}}*e^{\frac{x^{2}}{2}}dx = \frac{1}{2}\cdot \operatorname{erf}\left( \frac{x}{\sqrt{2}} \right)Parameters
x
Any number

Returns the median of the given numbers. The median is the number in the middle of a set of numbers.
If there is an even number of numbers in the set, then MEDIAN calculates the average of the two numbers in the middle.
Declaration
Swift
var median: BigNumber { get }

Returns corresponding quantile
In statistics and probability quantiles are cut points dividing the range of a probability distribution into continuous intervals with equal probabilities, or dividing the observations in a sample in the same way. There is one fewer quantile than the number of groups created. Thus quartiles are the three cut points that will divide a dataset into four equalsized groups. Common quantiles have special names: for instance quartile, decile (creating 10 groups: see below for more). The groups created are termed halves, thirds, quarters, etc., though sometimes the terms for the quantile are used for the groups created, rather than for the cut points.
Declaration
Swift
func quantile(percentage: Double) throws > BigNumber
Parameters
percentage
The percentage of distribution (ex: 0.25 is the first quartile)

Linear regression on a set of points
Returns an affine function going through the set of point.
Declaration
Swift
static func linearRegression(points: [Point]) throws > Polynomial
Parameters
points
A set of points

Returns the standard deviation of the list
The standard deviation (SD, also represented by the lower case Greek letter sigma σ for the population standard deviation or the Latin letter s for the sample standard deviation) is a measure of the amount of variation or dispersion of a set of values. A low standard deviation indicates that the values tend to be close to the mean (also called the expected value) of the set, while a high standard deviation indicates that the values are spread out over a wider range.
Computed using:
\sigma = \sqrt{\frac{\sum_{}^{}(x\bar{x})^2}{n1}}Declaration
Swift
var standardDeviation: BigNumber { get }

Returns the variance of the list
In probability theory and statistics, variance is the expectation of the squared deviation of a random variable from its mean. Informally, it measures how far a set of (random) numbers are spread out from their average value.
Computed using:
V = \sigma^2 = \frac{\sum_{}^{}(x\bar{x})^2}{n1}Declaration
Swift
var variance: BigNumber { get }