alfainv: Inverse of the alpha-transformation

In Compositional: Compositional Data Analysis

Description Usage Arguments Details Value Author(s) References See Also Examples

View source: R/alfainv.R

Description

The inverse of the α-transformation.

Usage

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alfainv(x, a, h = TRUE)

Arguments

Details

The inverse of the α-transformation is applied to the data. If the data lie outside the α-space, NAs will be returned for some values.

Value

A matrix with the pairwise distances.

Author(s)

Michail Tsagris

R implementation and documentation: Michail Tsagris <mtsagris@yahoo.gr> and Giorgos Athineou <athineou@csd.uoc.gr>

References

Tsagris M.T., Preston S. and Wood A.T.A. (2016). Improved classification for compositional data using the α-transformation. Journal of Classification (to appear). http://arxiv.org/pdf/1506.04976v2.pdf

Tsagris M.T., Preston S. and Wood A.T.A. (2011). A data-based power transformation for compositional data. In Proceedings of the 4th Compositional Data Analysis Workshop, Girona, Spain. http://arxiv.org/pdf/1106.1451.pdf

See Also

alfa, alfadist

Examples

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library(MASS)
x <- as.matrix(fgl[1:10, 2:9])
x <- x / rowSums(x)
y <- alfa(x, 0.5)$aff
alfainv(y, 0.5)