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sn (version 2.1.2)

The Skew-Normal and Related Distributions Such as the Skew-t and the SUN

Description

Build and manipulate probability distributions of the skew-normal family and some related ones, notably the skew-t and the SUN families. For the skew-normal and the skew-t distributions, statistical methods are provided for data fitting and model diagnostics, in the univariate and the multivariate case.

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Install

install.packages('sn')

Monthly Downloads

19,550

Version

2.1.2

License

GPL-2 | GPL-3

Maintainer

Adelchi Azzalini

Last Published

January 25th, 2026

Functions in sn (2.1.2)

Confidence intervals for parameters of a selm-class object

convertSN2SUNdistr

Convert a SN distribution into a SUN

Multivariate skew-normal distribution

Skew-Cauchy Distribution

Coefficients of objects created by selm

Skew-Normal Distribution

Conversion between parametrizations of a skew-elliptical distribution

convertCSN2SUNpar

Conversion of CSN parameters to SUN parameters

Multivariate skew-\(t\) distribution and skew-Cauchy distribution

conditionalSECdistr

Skew-normal conditional distribution

Skew-\(t\) Distribution

Simulated sample from a skew-normal distribution

galton_moors2alpha_nu

Mapping of the (Galton-Bowley, Moors) measures to the (\(alpha\), \(nu\)) parameters of a ST distribution

fitdistr.grouped-class

Methods for objects of class created by fitdistr.grouped

vech, tr and other matrix operators

Build an object representing a SUN distribution

Build a skew-elliptically contoured distribution

extractSECdistr

Extract the SEC error distribution from an object created by selm

Four-number summary of a numeric vector

fitdistr.grouped

Maximum-likelihood fitting of a univariate distribution from grouped data

The distribution of the product of two jointly normal or t variables

Profile log-likelihood function of selm-class objects

Plotting methods for classes SECdistrUv and SECdistrMv

Diagnostic plots for selm fits

Package sn: overview of the structure and main commands

Predict method for selm-class objects

plot.fitdistr.grouped

Plot an object generated by fitdistr.grouped

Residuals and fitted values from selm fits

plot.SUNdistr-method

Plotting method for class SUNdistr

The mode of a skew-elliptically contoured (SEC) distribution

Expected and observed Fisher information for SN and ST distributions

Spreading grouped data over intervals

summary.SECdistrMv-class

Classes summary.SECdistrMv and summary.SECdistrUv

Compute preliminary estimates for a linear model with ST-distributed error term

Standard deviation

Package sn: overview, background and history

Fitting linear models with skew-elliptical error term

sn-st.cumulants

Cumulants of univariate skew-normal and skew-\(t\) distributions

Classes selm and mselm of objects created by function selm

Function \(\log(2\,\Phi(x))\) and its derivatives

Piedmont wines data

symm-modulated-distr

Symmetry-modulated distributions

summary.SUNdistr-class

Class summary.SUNdistr

summary.SECdistr

Summary of a SEC distribution object

Summarizing selm fits

summary.SUNdistr

Summary of a SUN distribution object

Fitting functions for selm models

Australian Institute of Sport data

Penalty function for log-likelihood of selm models

Owen's function

SECdistrUv-class

Class "SECdistrUv"

The Unified Skew-Normal (SUN) probability distribution

SECdistrMv-class

Class "SECdistrMv"

Price of Barolo wine

Class "SUNdistr" and its methods

affineTransSECdistr

Affine transformations and marginals of a skew-elliptical distribution

Operations on SUNdistr-class objects