The Box-Cox transformation applied to ratios of components {Compositional} | R Documentation |
The Box-Cox transformation applied to ratios of components.
bc(x, lambda)
x |
A matrix with the compositional data. The first component must be zero values free. |
lambda |
The value of the power transformation, it has to be between -1 and 1. If zero values are present it has to
be greater than 0. If λ=0 the additive log-ratio transformation ( |
The Box-Cox transformation applied to ratios of components, as described in Aitchison (1986) is applied.
A matrix with the transformed data.
Michail Tsagris.
R implementation and documentation: Michail Tsagris mtsagris@uoc.gr.
Aitchison J. (1986). The statistical analysis of compositional data. Chapman & Hall.
library(MASS) x <- as.matrix(fgl[, 2:9]) x <- x / rowSums(x) y1 <- bc(x, 0.2) y2 <- bc(x, 0) rbind( colMeans(y1), colMeans(y2) ) rowSums(y1) rowSums(y2)