isoPortionLines: Isoportion- and Isoproportion-lines

Description

Add lines of equal portion and proportion to ternary diagrams, to serve as reference axis.

Usage

isoPortionLines(...)
# S3 method for acomp
isoPortionLines(by=0.2,at=seq(0,1,by=by),...,
                      parts=1:3,total=1,labs=TRUE,lines=TRUE,unit="")
# S3 method for rcomp
isoPortionLines(by=0.2,at=seq(0,1,by=by),...,
                      parts=1:3,total=1,labs=TRUE,lines=TRUE,unit="")
isoProportionLines(...)
# S3 method for acomp
isoProportionLines(by=0.2,at=seq(0,1,by=by),...,
                      parts=1:3,labs=TRUE,lines=TRUE) 
# S3 method for rcomp
isoProportionLines(by=0.2,at=seq(0,1,by=by),...,
                      parts=1:3,labs=TRUE,lines=TRUE)

Arguments

…

graphical arguments

numeric in [0,1]: which portions/proportions should be marked?

numeric in (0,1]: steps between protions/proportions

parts

numeric vector subset of {1,2,3}: the variables to be marked

total

the total amount to be used in labeling

labs

logical: plot the labels?

lines

logical: plot the lines?

unit

mark of the units e.g. "%"

Details

Isoportion lines give lines of the same portion of one of the parts, while isoproportion line gives lines of the same ratio between two parts. The isoproportion lines are straight lines in both the Aitchison and the real geometries of the simplex, while the isoportion lines are not straight in an Aitchison sense (only in the real one). However, note that both types of lines remain straight in the real sense when perturbed (von Eynatten et al., 2002).

References

von Eynatten, H., V. Pawlowsky-Glahn, and J.J. Egozcue (2002) Understanding perturbation on the simplex: a simple method to better visualize and interpret compositional data in ternary diagrams. Mathematical Geology 34, 249-257

Examples

Run this code

# NOT RUN {
data(SimulatedAmounts)
plot(acomp(sa.lognormals))
isoPortionLines()
plot(acomp(sa.lognormals),center=TRUE)
isoPortionLines()
plot(rcomp(sa.lognormals))
isoPortionLines()
plot(acomp(sa.lognormals))
isoProportionLines()
plot(acomp(sa.lognormals),center=TRUE)
isoProportionLines()
plot(rcomp(sa.lognormals))
isoProportionLines()
# }