Computes PLR transformations.
Usage
transform_plr(object, ...)
# S4 method for class 'CompositionMatrix'
transform_plr(object, pivot = 1)
# S4 method for class 'GroupedComposition'
transform_plr(object, pivot = 1)Arguments
- object
A
CompositionMatrixobject.- ...
Currently not used.
- pivot
An
integergiving the index of the pivotal variable.
Value
A PLR object.
References
Fišerová, E. & Hron, K. (2011). On the Interpretation of Orthonormal Coordinates for Compositional Data. Mathematical Geosciences, 43(4), 455‑468. doi:10.1007/s11004-011-9333-x .
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 .
Hron, K., Filzmoser, P., de Caritat, P., Fišerová, E. & Gardlo, A. (2017). Weighted Pivot Coordinates for Compositional Data and Their Application to Geochemical Mapping. Mathematical Geosciences, 49(6), 797-814. doi:10.1007/s11004-017-9684-z .
See also
Other log-ratio transformations:
transform_alr(),
transform_clr(),
transform_ilr(),
transform_inverse(),
transform_lr()
Examples
## Data from Aitchison 1986
data("hongite")
## Coerce to compositional data
coda <- as_composition(hongite)
## Isometric log-ratio
ilr <- transform_ilr(coda)
plr <- transform_plr(coda)
## Inverse transformation
inv_ilr <- transform_inverse(ilr)
all.equal(coda, inv_ilr)
#> [1] TRUE
inv_plr <- transform_inverse(plr)
all.equal(coda, inv_plr)
#> [1] TRUE