lrpca {ToolsForCoDa}

Logratio principal component analysis with condition indices

Description

Function lrpca performs logratio principal component analysis. It returns the variance decomposition, principal components, biplot coordinates and a table with condition indices.

Usage

lrpca(Xcom)

Arguments

Xcom

A matrix with compositions in its rows

Details

Calculations are based on the singular value decompositon of the clr transformed compositions.

Value

Fp

matrix with principal components

Fs

matrix with standardized principal components

Gp

biplot markers for parts (principal coordinates)

Gs

biplot markers for parts (standard coordinates)

La

eigenvalues

D

singular values

decom

table with variance decomposition

kappalist

table with condition indices and eigenvectors

Author(s)

Jan Graffelman ([e-mail])

See Also

princomp,

Examples

data(bentonites)
Ben <- bentonites[,1:8]
Ben.com <- Ben/rowSums(Ben)
out.lrpca <- lrpca(Ben.com)