idt {compositions} | R Documentation |
Compute the isometric default transform of a vector (or dataset) of compositions or amounts in the selected class.
idt(x) ## Default S3 method: idt( x ) ## S3 method for class 'acomp': idt( x ) ## S3 method for class 'rcomp': idt( x ) ## S3 method for class 'aplus': idt( x ) ## S3 method for class 'rplus': idt( x ) ## S3 method for class 'rmult': idt( x ) ## S3 method for class 'factor': idt( x )
x |
a classed amount or composition, to be transformed with its isometric default transform |
The general idea of this package is to analyse the same data with
different geometric concepts, in a fashion as similar as possible. For each of the
four concepts there exists an isometric transform expressing the geometry
in a full-rank euclidean vector space. Such a transformation is computed by idt
. For
acomp
the transform is ilr
, for
rcomp
it is ipt
, for
aplus
it is ilt
, and for
rplus
it is iit
. Keep in mind that the
transform does not keep the variable names, since there is no guaranteed
one-to-one relation between the original parts and each transformed variable.
A corresponding matrix of row-vectors containing the transforms.
## Not run: # the idt is defined by idt <- function(x) UseMethod("idt",x) idt.default <- function(x) x idt.acomp <- function(x) ilr(x) idt.rcomp <- function(x) ipt(x) idt.aplus <- ilt idt.rplus <- iit ## End(Not run) idt(acomp(1:5)) idt(rcomp(1:5))