transform_inverse: Inverse Log-Ratio Transformation

In nexus: Sourcing Archaeological Materials by Chemical Composition

Inverse Log-Ratio Transformation

Description

Computes inverse log-ratio transformations.

Usage

transform_inverse(object, origin, ...)

## S4 method for signature 'CLR,missing'
transform_inverse(object)

## S4 method for signature 'ALR,missing'
transform_inverse(object)

## S4 method for signature 'ILR,missing'
transform_inverse(object)

## S4 method for signature 'matrix,ILR'
transform_inverse(object, origin)

Arguments

object	A LogRatio object.
origin	A LogRatio object to be used for the inverse transformation.
...	Currently not used.

Value

A CompositionMatrix object.

Author(s)

N. Frerebeau

References

Aitchison, J. (1986). The Statistical Analysis of Compositional Data. London: Chapman and Hall.

Egozcue, J. J., Pawlowsky-Glahn, V., Mateu-Figueras, G. & Barceló-Vidal, C. (2003). Isometric Logratio Transformations for Compositional Data Analysis. Mathematical Geology, 35(3), 279-300. \Sexpr[results=rd]{tools:::Rd_expr_doi("10.1023/A:1023818214614")}.

Fišerová, E. & Hron, K. (2011). On the Interpretation of Orthonormal Coordinates for Compositional Data. Mathematical Geosciences, 43(4), 455‑468. \Sexpr[results=rd]{tools:::Rd_expr_doi("10.1007/s11004-011-9333-x")}.

Greenacre, M. J. (2019). Compositional Data Analysis in Practice. Boca Raton: CRC Press.

See Also

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

Examples

## Data from Aitchison 1986
data("hongite")

## Coerce to compositional data
coda <- as_composition(hongite)

## Centered log-ratio
clr <- transform_clr(coda)

## Inverse transformation
inv_clr <- transform_inverse(clr)
all.equal(coda, inv_clr)

nexus documentation built on Sept. 11, 2024, 6:43 p.m.