clr {robCompositions}R Documentation

Centred log-ratio transformation

Description

The clr transformation moves D-part compositional data from the simplex into a D-dimensional real space.

Usage

clr(x)

Arguments

x multivariate data ideally of class data.frame or matrix

Details

Each composition is divided by the geometric mean of its parts before the logarithm is taken.

Value

The transformed data, including

x.clr clr transformed data
gm the geometric means of the original composition.

Note

The resulting transformed data set is singular by definition.

Author(s)

Matthias Templ

References

Aitchison, J. (1986) The Statistical Analysis of Compositional Data Monographs on Statistics and Applied Probability. Chapman & Hall Ltd., London (UK). 416p.

See Also

invclr, alr, ilr, invalr, invilr

Examples

data(expenditures)
eclr <- clr(expenditures)
inveclr <- invclr(eclr)
head(expenditures)
head(inveclr)
head(invclr(eclr$x.clr))

[Package robCompositions version 1.3.3 Index]