| variation {compositions} | R Documentation |
Compute the variation matrix in the various approaches of compositional and amount data analysis. Pay attention that this is not computing the variance or covariance matrix!
variation(x,...)
## S3 method for class 'acomp':
variation(x, ...)
## S3 method for class 'rcomp':
variation(x, ...)
## S3 method for class 'aplus':
variation(x, ...)
## S3 method for class 'rplus':
variation(x, ...)
## S3 method for class 'rmult':
variation(x, ...)
x |
a dataset, eventually of amounts or compositions |
... |
currently unused |
The variation matrix was defined in the acomp context of
analysis of compositions as the matrix of variances of all
possible log-ratios among components (Aitchison, 1986). The
generalization to rcomp objects is simply to reproduce the
variance of all possible differences between components. The
amount (aplus, rplus) and rmult objects
should not be treated with variation
matrices, because this was intended to skip the existence of a closure
(which does not exist in the case of amounts).
The variation matrix of x.
K.Gerald v.d. Boogaart http://www.stat.boogaart.de
cdt, clrvar2ilr, clo,
mean.acomp, acomp, rcomp,
aplus, rplus
data(SimulatedAmounts) mean.col(sa.lognormals) variation(acomp(sa.lognormals)) variation(rcomp(sa.lognormals)) variation(aplus(sa.lognormals)) variation(rplus(sa.lognormals)) variation(rmult(sa.lognormals))