alr_basis {coda.base} | R Documentation |
Compute the transformation matrix to express a composition using the oblique additive log-ratio coordinates.
alr_basis(dim, denominator = dim, numerator = which(denominator != 1:dim))
dim |
number of parts |
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. |
matrix
Aitchison, J. (1986) The Statistical Analysis of Compositional Data. Monographs on Statistics and Applied Probability. Chapman & Hall Ltd., London (UK). 416p.
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))