variation {compositions}R Documentation

Variation matrices of amounts and compositions

Description

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!

Usage

          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, ...)
          

Arguments

x a dataset, eventually of amounts or compositions
... currently unused

Details

The variation matrix was defined in the acomp context for 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 and rmult objects should not be treated with variation matrices, because this implies always the existence of a closure.

Value

The variation matrix of x.

See Also

cdt, clrvar2ilr, clo, mean.acomp, acomp, rcomp, aplus, rplus

Examples

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))


[Package compositions version 0.9-10 Index]