Common

public struct Common

Common Statistical Functions

This struct is used as a namespace to separate the stats functions in SwiftStats.

In general, the functions here do not throw exceptions but nil values can be returned. For example, to calculate the standard deviation of a sample requires at least two data points. If the array that is passed to sd() does not have at least two values then nil is returned.

Functions here are often generic in that they work for a range of types (for example, the same function is called to calculate the mean of Int8, Int32, Int64, or Int arrays). Separate implementations can be found for BinaryInteger and BinaryFloatingPoint protocols.

  • Calculate n! for values of n that conform to the BinaryInteger protocol. Returns nil if n is less than zero.

    Declaration

    Swift

    public static func factorial<T>(_ n: T) -> Int? where T : BinaryInteger

  • Calculate n! for values of n that conform to the BinaryFloatingPoint protocol. Uses the gamma function to fill in values of n that are not integers. Returns nil if n is less than zero.

    Declaration

    Swift

    public static func factorial<T>(_ n: T) -> Double? where T : BinaryFloatingPoint

  • Calculate n-choose-k for values of n and k that conform to the BinaryInteger protocol.

    Declaration

    Swift

    public static func choose<T>(n: T, k: T) -> Int where T : BinaryInteger

  • Calculate n-choose-k for values of n that conform to the BinaryFloatingPoint protocol and values of k that conform to the BinaryInteger protocol.

    Declaration

    Swift

    public static func choose<N, K>(n: N, k: K) -> Double where N : BinaryFloatingPoint, K : BinaryInteger

  • Calculates the mean of an array of values for types that satisfy the BinaryInteger protocol (e.g Int, Int32).

    Declaration

    Swift

    public static func mean<T>(_ data: [T]) -> Double? where T : BinaryInteger

    Parameters

    data

    Array of values

    Return Value

    The mean of the array of values or nil if the array was empty.

  • Calculates the mean of an array of values for types that satisfy the BinaryFloatingPoint protocol (e.g Float, Double).

    Declaration

    Swift

    public static func mean<T>(_ data: [T]) -> Double? where T : BinaryFloatingPoint

    Parameters

    data

    Array of values

    Return Value

    The mean of the array of values or nil if the array was empty.

  • Calculates the unbiased sample variance for an array for types that satisfy the BinaryFloatingPoint protocol (e.g Float, Double).

    Declaration

    Swift

    public static func variance<T>(_ data: [T]) -> Double? where T : BinaryFloatingPoint

    Parameters

    data

    Sample of values. Note that this should contain at least two values.

    Return Value

    The unbiased sample variance or nil if data contains fewer than two values.

  • Calculates the unbiased sample standard deviation for an array of values for types that satisfy the BinaryFloatingPoint protocol (e.g Float, Double).

    Declaration

    Swift

    public static func sd<T>(_ data: [T]) -> Double? where T : BinaryFloatingPoint

    Parameters

    data

    Sample of values. Note that this should contain at least two values.

    Return Value

    The sample unbiased standard deviation or nil if data contains fewer than two values.

  • Calculates the unbiased sample standard deviation for an array of values for types that satisfy the BinaryInteger protocol (e.g Int, Int32).

    Declaration

    Swift

    public static func sd<T>(_ data: [T]) -> Double? where T : BinaryInteger

    Parameters

    data

    Sample of values. Note that this should contain at least two values.

    Return Value

    The sample unbiased standard deviation or nil if data contains fewer than two values.

  • Calculates the population variance for an array of values for types that satisfy the BinaryFloatingPoint protocol (e.g Float, Double).

    Declaration

    Swift

    public static func pvariance<T>(_ data: [T]) -> Double? where T : BinaryFloatingPoint

    Parameters

    data

    Values of population. Note that this should contain at least one value.

    Return Value

    The population variance or nil if data contains fewer than one value.

  • Calculates the unbiased sample variance for an array of values for types that satisfy the BinaryInteger protocol (e.g Int, Int32).

    Declaration

    Swift

    public static func variance<T>(_ data: [T]) -> Double? where T : BinaryInteger

    Parameters

    data

    Sample of values. Note that this should contain at least two values.

    Return Value

    The unbiased sample variance or nil if data contains fewer than two values.

  • Calculates the population variance for an array of values for types that satisfy the BinaryInteger protocol (e.g Int, Int32).

    Declaration

    Swift

    public static func pvariance<T>(_ data: [T]) -> Double? where T : BinaryInteger

    Parameters

    data

    Values of population. Note that this should contain at least one value.

    Return Value

    The population variance or nil if data contains fewer than one value.

  • Calculates the median of an array of values for types that satisfy the BinaryFloatingPoint protocol (e.g Float, Double).

    Declaration

    Swift

    public static func median<T>(_ data: [T]) -> Double? where T : BinaryFloatingPoint

    Parameters

    data

    Values of population. Note that this should contain at least one value.

    Return Value

    The population variance or nil if data contains fewer than one value.

  • Calculates the median of an array of values for types that satisfy the BinaryInteger protocol (e.g Int, Int32).

    Declaration

    Swift

    public static func median<T>(_ data: [T]) -> Double? where T : BinaryInteger

    Parameters

    data

    Values of population. Note that this should contain at least one value.

    Return Value

    The population variance or nil if data contains fewer than one value.

  • Undocumented

    Declaration

    Swift

    public static func erfinv(_ y: Double) -> Double

  • Undocumented

    Declaration

    Swift

    public static func lsr(_ points: [[Double]]) -> [Double]