clr2ilr {compositions} | R Documentation |
Compute the centered log ratio transform of a (dataset of) isometric log-ratio transform(s) and its inverse. Equivalently, compute centered and isometric planar transforms from each other.
clr2ilr( x , V=ilrBase(x) ) ilr2clr( z , V=ilrBase(z=z) ) clrvar2ilr( varx , V=ilrBase(D=ncol(varx)) ) ilrvar2clr( varz , V=ilrBase(D=ncol(varz)+1) )
x |
the clr/cpt-transform of composition(s) |
z |
the ilr/ipt-transform of composition(s) |
varx |
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 |
These functions perform a matrix multiplication with V
in an
appropriate way.
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
gives the variance-/covariance-matrix of the clr/cpt
transform of the same compositional data set.
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
data(SimulatedAmounts) ilr.inv(clr2ilr(clr(sa.lognormals)))-clo(sa.lognormals) clr.inv(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))