| skew {semTools} | R Documentation |
Finding skewness (g1) of an object
skew(object, population=FALSE)
object |
A vector used to find a skewness |
population |
|
The skewness computed is g1. The parameter skewness γ_{2} formula is
γ_{2} = \frac{μ_{3}}{μ^{3/2}_{2}},
where μ_{i} denotes the i order central moment.
The excessive kurtosis formula for sample statistic g_{2} is
g_{2} = \frac{k_{3}}{k^{2}_{2}},
where k_{i} are the i order k-statistic.
The standard error of the skewness is
Var(\hat{g}_2) = \frac{6}{N}
where N is the sample size.
A value of a skewness with a test statistic if the population is specified as FALSE
Sunthud Pornprasertmanit (psunthud@gmail.com)
Weisstein, Eric W. (n.d.). Skewness. Retrived from MathWorld–A Wolfram Web Resource http://mathworld.wolfram.com/Skewness.html
kurtosis Find the univariate excessive kurtosis of a variable
mardiaSkew Find the Mardia's multivariate skewness of a set of variables
mardiaKurtosis Find the Mardia's multivariate kurtosis of a set of variables
skew(1:5)