compositions: clr2ilr – R documentation

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clr2ilr

Convert between clr and ilr, and between cpt and ipt.

Description

Compute the centered log ratio transform of a (dataset of) from isometric log-ratio transform(s) and its inverse. Equivalently, compute centered and isometric planar transforms from each other. Acts in vectors and in bilinear forms. For bilinear forms, transform between variation-form from clr-form.

Usage

clr2ilr( x , V=ilrBase(x=x) )
ilr2clr( z , V=ilrBase(z=z), x=gsi.orig(z) )
clrvar2ilr( varx , V=ilrBase(D=ncol(varx)) )
ilrvar2clr( varz , V=ilrBase(D=ncol(varz)+1) ,x=NULL)
clrvar2variation(Sigma)
variation2clrvar(TT)
is.clrvar(M, tol=1e-10)
is.ilrvar(M, tol=1e-10)

Arguments

`x`	the clr/cpt-transform of composition(s) (in the ilr2-routines provided only to give column names.)
`z`	the ilr/ipt-transform of composition(s)
`varx, Sigma`	variance or covariance matrix of clr/cpt-transformed compositions
`varz`	variance or covariance matrix of ilr/ipt-transformed compositions
`V`	a matrix with columns giving the chosen basis of the clr-plane
`TT`	variation matrix
`M`	a matrix, to check if it is a valid variance
`tol`	tolerance for the check

Details

These functions perform a matrix multiplication with V in an appropriate way.

Value

clr2ilr gives the ilr/ipt transform of the same composition(s),
ilr2clr gives the clr/cpt transform of the same composition(s),
clrvar2ilr gives the variance-/covariance-matrix of the ilr/ipt transform of the same compositional data set,
ilrvar2clr and clrvar2variation give the variance-/covariance-matrix of the clr/cpt transform of the same compositional data set.
variation2clrvar gives the variation matrix from the clr-covariance matrix
is.*var check if the given matrix satisfies the conditions to be an ilr-variance resp. a clr-variance

Author(s)

K.Gerald v.d. Boogaart http://www.stat.boogaart.de

References

Egozcue J.J., V. Pawlowsky-Glahn, G. Mateu-Figueras and C. Barcel'o-Vidal (2003) Isometric logratio transformations for compositional data analysis. Mathematical Geology, 35(3) 279-300
Aitchison, J, C. Barcel'o-Vidal, J.J. Egozcue, V. Pawlowsky-Glahn (2002) A consise guide to the algebraic geometric structure of the simplex, the sample space for compositional data analysis, Terra Nostra, Schriften der Alfred Wegener-Stiftung, 03/2003

Examples

data(SimulatedAmounts)
ilrInv(clr2ilr(clr(sa.lognormals)))-clo(sa.lognormals)
clrInv(ilr2clr(ilr(sa.lognormals)))-clo(sa.lognormals)
ilrvar2clr(var(ilr(sa.lognormals)))-var(clr(sa.lognormals))
clrvar2ilr(var(cpt(sa.lognormals)))-var(ipt(sa.lognormals))
variation(acomp(sa.lognormals))
clrvar2variation(var(acomp(sa.lognormals)))

compositions

Compositional Data Analysis

v2.0-1

GPL (>= 2)

Authors

K. Gerald van den Boogaart <boogaart@hzdr.de>, Raimon Tolosana-Delgado, Matevz Bren

Initial release

2021-01-08