Last data update: 2014.03.03

R: Skewness coefficients of a folder of data sets
skewnessfR Documentation

Skewness coefficients of a folder of data sets

Description

Computes the skewness coefficient by column of the elements of an object of class folder.

Usage

skewnessf(fold, na.rm = FALSE)

Arguments

fold

an object of class folder. The attribute attr(,"same.cols") must be TRUE (otherwise, there is an error).

na.rm

logical. Should missing values be omitted from the calculations? (see skewness)

Details

This function can only be applied to a folder of data frames with the same column names. If attr(fold,"same.cols") = FALSE, there is an error.

It uses skewness to compute the mean by numeric column of each element of the folder. If some columns of the data frames are not numeric, there is a warning, and the means are computed on the numeric columns only.

Value

A list whose elements are the skewness coefficients by column of the elements of the folder.

Author(s)

Rachid Boumaza, Pierre Santagostini, Smail Yousfi, Sabine Demotes-Mainard

Maintainer: Rachid Boumaza <rachid.boumaza@agrocampus-ouest.fr>

See Also

folder to create an object is of class folder. meanf, varf, corf, kurtosisf for other statistics for folder objects.

Examples

# First example: iris (Fisher)               
data(iris)
iris.fold <- df2folder(iris, "Species")
iris.skewness <- skewnessf(iris.fold)
print(iris.skewness)

# Second example: roses
data(roses)
roses.fold <- df2folder(roses, "Lot")
roses.skewness <- skewnessf(roses.fold)
print(roses.skewness)

Results