ilr_basis {coda.base}R Documentation

Default Isometric log-ratio basis

Description

Build an isometric log-ratio basis for a composition with k+1 parts

h[i] = √(i/(i+1)) ( log(x[1] … x[i])/i - log(x[i+1]) )

for i in 1… k.

Usage

ilr_basis(dim, type = "default")

Arguments

dim

number of components

type

if different than 'pivot' (pivot balances) or 'cdp' (codapack balances) default balances are returned, which computes a triangular Helmert matrix as defined by Egozcue et al., 2013.

Details

Modifying parameter type (pivot or cdp) other ilr basis can be generated

Value

matrix

References

Egozcue, J.J., Pawlowsky-Glahn, V., Mateu-Figueras, G. and Barceló-Vidal C. (2003). Isometric logratio transformations for compositional data analysis. Mathematical Geology, 35(3) 279-300

Examples

ilr_basis(5)

[Package coda.base version 0.3.1 Index]