Inverse additive log-ratio transformation, often called additive logistic transformation.
Usage
invalr(x, cnames = NULL, ivar = NULL, useClassInfo = TRUE)
Arguments
x
data set, object of class alr, matrix or data.frame
cnames
column names. If the object is of class alr the column names are chosen from therein.
ivar
index of the rationing part. If the object is of class 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.
useClassInfo
if FALSE, the class information of object x is not used.
Value
the transformed data matrix
Details
The function allows also to preserve absolute values when class info is provided. Otherwise only the relative information is preserved.
References
Aitchison, J. (1986) The Statistical Analysis of Compositional
Data Monographs on Statistics and Applied Probability. Chapman &
Hall Ltd., London (UK). 416p.