https://github.com/cran/robCompositions
Tip revision: 45c93a18fe3e83941bd865d89680d47d6b1d846e authored by Matthias Templ on 15 May 2012, 00:00:00 UTC
version 1.6.0
version 1.6.0
Tip revision: 45c93a1
ternaryDiagAbline.R
ternaryDiagAbline <- function(x, ...){
if(ncol(x) > 2) stop("it is assumed that the 2-dim points are provided in the transformed space.")
# plot(x)
k <- (x[2,2]-x[1,2])/(x[2,1]-x[1,1])
a <- c(0,c(x[1,2]-k*(x[1,1])))
fk <- function(x,a,k){
y <- k*x+a[2]
y
}
SEQ <- seq(-10,10,length=1000)
x <- fk(SEQ,a,k)
# print(x)
x <- cbind(SEQ,x)
# lines(x)
# print(x)
x <- invilr(x)
s <- rowSums(x)
if (any(s <= 0))
stop("rowSums of the input data x must be positive.")
x <- x/s
top <- sqrt(3)/2
xp <- x[, 2] + x[, 3]/2
yp <- x[, 3] * top
lines(xp, yp, ...)
}