compositions (version 2.0-8)

ratioLoadings: Loadings of relations of two amounts

Description

In a compositional dataset the relation of two objects can be interpreted safer than a single amount. These functions compute, display and plot the corresponding pair-information for the various principal component analysis results.

Usage

relativeLoadings(x,...)
# S3 method for princomp.acomp
relativeLoadings(x,...,log=FALSE,scale.sdev=NA,
                                                  cutoff=0.1)
# S3 method for princomp.aplus
relativeLoadings(x,...,log=FALSE,scale.sdev=NA,
                                                  cutoff=0.1)
# S3 method for princomp.rcomp
relativeLoadings(x,...,scale.sdev=NA,
                                                  cutoff=0.1)
# S3 method for princomp.rplus
relativeLoadings(x,...,scale.sdev=NA,
                                                  cutoff=0.1)
# S3 method for relativeLoadings.princomp.acomp
print(x,...,cutoff=attr(x,"cutoff"),
                                                  digits=2)
# S3 method for relativeLoadings.princomp.aplus
print(x,...,cutoff=attr(x,"cutoff"),
                                                 digits=2)
# S3 method for relativeLoadings.princomp.rcomp
print(x,...,cutoff=attr(x,"cutoff"),
                                                 digits=2)
# S3 method for relativeLoadings.princomp.rplus
print(x,...,cutoff=attr(x,"cutoff"),
                                                 digits=2)
# S3 method for relativeLoadings.princomp.acomp
plot(x,...)
# S3 method for relativeLoadings.princomp.aplus
plot(x,...)
# S3 method for relativeLoadings.princomp.rcomp
plot(x,...)
# S3 method for relativeLoadings.princomp.rplus
plot(x,...)

Value

The value is a matrix of type

"relativeLoadings.princomp.*", containing the ratios in the compositions represented by the loadings (optionally scaled by the standard deviation of the components and scale.sdev).

Arguments

x

a result from an amount PCA princomp.acomp/princomp.aplus/princomp.rcomp/princomp.rplus

log

a logical indicating to use log-ratios instead of ratios

scale.sdev

if not NA, a number specifying the multiple of a standard deviation, used to scale the components

cutoff

a single number. Changes under that (log)-cutoff are not displayed

digits

the number of digits to be displayed

...

further parameters to internally-called functions

Author

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

Details

The relative loadings of components allow a direct interpretation of the effects of principal components. For acomp/aplus classes the relation is induced by a ratio, which can optionally be log-transformed. For the rcomp/rplus-classes the relation is induced by a difference, which is meaningless when the units are different.

See Also

princomp.acomp, princomp.aplus, princomp.rcomp, princomp.rplus, barplot

Examples

data(SimulatedAmounts)
pc <- princomp(acomp(sa.lognormals5))
pc
summary(pc)
relativeLoadings(pc,log=TRUE)
relativeLoadings(pc)
relativeLoadings(pc,scale.sdev=1)
relativeLoadings(pc,scale.sdev=2)

plot(relativeLoadings(pc,log=TRUE))
plot(relativeLoadings(pc))
plot(relativeLoadings(pc,scale.sdev=1))
plot(relativeLoadings(pc,scale.sdev=2))