transform_plr function

Pivot Log-Ratios (PLR)

Computes PLR transformations. methods

transform_plr(object, ...)

## S4 method for signature 'CompositionMatrix'
transform_plr(object, pivot = 1)

## S4 method for signature 'GroupedComposition'
transform_plr(object, pivot = 1)

Arguments

• object: A CompositionMatrix object.
• ...: Currently not used.
• pivot: An integer giving the index of the pivotal variable.

Returns

A PLR object.

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)

inv_plr <- transform_inverse(plr)
all.equal(coda, inv_plr)

References

Fišerová, E. & Hron, K. (2011). On the Interpretation of Orthonormal Coordinates for Compositional Data. Mathematical Geosciences, 43(4), 455‑468. tools:::Rd_expr_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. tools:::Rd_expr_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. tools:::Rd_expr_doi("10.1007/s11004-017-9684-z") .

See Also

Other log-ratio transformations: transform_alr(), transform_clr(), transform_ilr(), transform_inverse(), transform_lr()

Author(s)

N. Frerebeau