% Generated by roxygen2: do not edit by hand
% Please edit documentation in R/addLRinv.R
\name{addLRinv}
\alias{addLRinv}
\title{Inverse additive logratio mapping}
\usage{
addLRinv(x, cnames = NULL, ivar = NULL, useClassInfo = TRUE)
}
\arguments{
\item{x}{data set, object of class \dQuote{alr}, \dQuote{matrix} or
\dQuote{data.frame}}

\item{cnames}{column names. If the object is of class \dQuote{alr} the
column names are chosen from therein.}

\item{ivar}{index of the rationing part. If the object is of class
\dQuote{alr} the column names are chosen from therein. If not and ivar is
not provided by the user, it is assumed that the rationing part was the last
column of the data in the simplex.}

\item{useClassInfo}{if FALSE, the class information of object \code{x} is
not used.}
}
\value{
the resulting compositional data matrix
}
\description{
Inverse additive logratio mapping, often called additive logistic
transformation.
}
\details{
The function allows also to preserve absolute values when class info is
provided. Otherwise only the relative information is preserved.
}
\examples{

data(arcticLake)
x <- arcticLake
x.alr <- addLR(x, 2)
y <- addLRinv(x.alr)
## This exactly fulfills:
addLRinv(addLR(x, 3))
data(expenditures)
x <- expenditures
y <- addLRinv(addLR(x, 5, 2))
head(x)
head(y)
## --> absolute values are preserved as well.

## preserve only the ratios:
addLRinv(x.alr, ivar=2, useClassInfo=FALSE)

}
\references{
Aitchison, J. (1986) \emph{The Statistical Analysis of
Compositional Data} Monographs on Statistics and Applied Probability.
Chapman \& Hall Ltd., London (UK). 416p.
}
\seealso{
\code{\link{pivotCoordInv}}, \code{\link{cenLRinv}},
\code{\link{cenLR}}, \code{\link{addLR}}
}
\author{
Matthias Templ
}
\keyword{manip}