alr_basis {coda.base} | R Documentation |
Additive log-ratio basis
Description
Compute the transformation matrix to express a composition using the oblique additive log-ratio coordinates.
Usage
alr_basis(dim, denominator = NULL, numerator = NULL)
Arguments
dim |
An integer indicating the number of components. If a dataframe or matrix is provided, the number of components is inferred from the number of columns. If a character vector specifying the names of the parts is provided the number of component is its length. |
denominator |
part used as denominator (default behaviour is to use last part) |
numerator |
parts to be used as numerator. By default all except the denominator parts are chosen following original order. |
Value
matrix
References
Aitchison, J. (1986) The Statistical Analysis of Compositional Data. Monographs on Statistics and Applied Probability. Chapman & Hall Ltd., London (UK). 416p.
Examples
alr_basis(5)
# Third part is used as denominator
alr_basis(5, 3)
# Third part is used as denominator, and
# other parts are rearranged
alr_basis(5, 3, c(1,5,2,4))
[Package coda.base version 1.0.3 Index]