transform_alr {nexus} | R Documentation |
Additive Log-Ratios (ALR)
Description
Computes ALR transformation.
Usage
transform_alr(object, ...)
## S4 method for signature 'CompositionMatrix'
transform_alr(object, j = ncol(object), weights = FALSE)
## S4 method for signature 'GroupedComposition'
transform_alr(object, j = ncol(object), weights = FALSE)
## S4 method for signature 'CLR'
transform_alr(object, j = ncol(object))
## S4 method for signature 'GroupedCLR'
transform_alr(object, j = ncol(object), weights = FALSE)
Arguments
object |
A |
... |
Currently not used. |
j |
An |
weights |
A |
Details
The ALR transformation is the logratio of a pair of parts with respect to a fixed part.
Value
An ALR
object.
Author(s)
N. Frerebeau
References
Aitchison, J. (1986). The Statistical Analysis of Compositional Data. London: Chapman and Hall.
Greenacre, M. J. (2019). Compositional Data Analysis in Practice. Boca Raton: CRC Press.
Greenacre, M. J. (2021). Compositional Data Analysis. Annual Review of Statistics and Its Application, 8(1): 271-299. doi:10.1146/annurev-statistics-042720-124436.
See Also
Other log-ratio transformations:
transform_clr()
,
transform_ilr()
,
transform_inverse()
,
transform_lr()
,
transform_plr()
Examples
## Data from Aitchison 1986
data("hongite")
## Coerce to compositional data
coda <- as_composition(hongite)
## Additive log-ratio
alr <- transform_alr(coda)
## Inverse transformation
inv_alr <- transform_inverse(alr)
all.equal(coda, inv_alr)