ilr {robCompositions} | R Documentation |
An isometric log-ratio transformation with a special choice of the balances according to Hron et al. (2009).
ilr(x)
x |
object of class data frame or matrix with positive entries |
This choice of the balances separates all the relative information of the part x_1 from the remaining parts. It is useful for estimating missing values in x_1 by regression of the remaining variables.
The ilr transformed data.
Karel Hron, Matthias Templ
Egozcue J.J., V. Pawlowsky-Glahn, G. Mateu-Figueras and C. Barcel'o-Vidal (2003) Isometric logratio transformations for compositional data analysis. Mathematical Geology, 35(3) 279-300 \
Hron, K. and Templ, M. and Filzmoser, P. (2008) Imputation of missing values for compositional data using classical and robust methods Research Report SM-2008-4, Vienna University of Technology, 15 pages.
require(MASS) Sigma <- matrix(c(5.05,4.95,4.95,5.05), ncol=2, byrow=TRUE) z <- invilr(mvrnorm(100, mu=c(0,2), Sigma=Sigma)) require(compositions) plot(acomp(z)) plot(invilr(z))