univariate_ilr {nexus} | R Documentation |
Univariate Isometric Log-Ratios (ILR)
Description
Computes univariate ILR coordinates.
Usage
univariate_ilr(object, ...)
## S4 method for signature 'numeric'
univariate_ilr(object)
## S4 method for signature 'matrix'
univariate_ilr(object)
Arguments
object |
A |
... |
Currently not used. |
Details
The ILR transformation provides the coordinates of any composition with
respect to a given orthonormal basis. transform_ilr()
uses the orthonormal
basis (Helmert matrix) originally defined by Egozcue et al. (2003).
Value
Same as object
.
Author(s)
N. Frerebeau
References
Filzmoser, P., Hron, K. & Reimann, C. (2009). Univariate Statistical Analysis of Environmental (Compositional) Data: Problems and Possibilities. Science of The Total Environment, 407(23), 6100-6108. doi:10.1016/j.scitotenv.2009.08.008.
Filzmoser, P., Hron, K. & Reimann, C. (2010). The Bivariate Statistical Analysis of Environmental (Compositional) Data. Science of The Total Environment, 408(19), 4230-4238. doi:10.1016/j.scitotenv.2010.05.011.
Examples
## Data from Aitchison 1986
data("hongite")
## Coerce to compositional data
coda <- as_composition(hongite)
## Isometric log-ratio
ilr <- transform_ilr(coda)
plr <- transform_plr(coda)
## Inverse transformation
inv_ilr <- transform_inverse(ilr)
all.equal(coda, inv_ilr)
inv_plr <- transform_inverse(plr)
all.equal(coda, inv_plr)