The pivot coordinate transformation and its inverse {Compositional}

The pivot coordinate transformation and its inverse

Description

The pivot coordinate transformation and its inverse.

Usage

pivot(x)
pivotinv(y)

Arguments

x

A numerical matrix with the compositional data.

y

A numerical matrix with data to be closed into the simplex.

Details

The pivot coordinate transformation and its inverse are computed. This means that no zeros are allowed.

Value

A matrix with the alr transformed data (if pivot is used) or with the compositional data (if the pivotinv is used).

Author(s)

Michail Tsagris.

R implementation and documentation: Michail Tsagris [e-mail].

References

Peter Filzmoser, Karel Hron and Matthias Templ (2018). Applied Compositional Data Analysis With Worked Examples in R (pages 49 and 51). Springer.

See Also

alfa, alfainv, alr, green

Examples

library(MASS)
x <- as.matrix(fgl[, 2:9])
x <- x / rowSums(x)
y <- pivot(x)
x1 <- alrinv(y)