inst-not/quantreg/quantreg-rqss-examples.R

In aphalo/ggpmisc: Miscellaneous Extensions to 'ggplot2'

library(quantreg)

n <- 200
x <- sort(rchisq(n,4))
z <- x + rnorm(n)
y <- log(x)+ .1*(log(x))^2 + log(x)*rnorm(n)/4 + z
plot(x, y-z)

f.N  <- rqss(y ~ qss(x, constraint= "N") + z)

f.I  <- rqss(y ~ qss(x, constraint= "I") + z)

f.CI <- rqss(y ~ qss(x, constraint= "CI") + z)

lines(x[-1], f.N $coef[1] + f.N $coef[-(1:2)])

lines(x[-1], f.I $coef[1] + f.I $coef[-(1:2)], col="blue")

lines(x[-1], f.CI$coef[1] + f.CI$coef[-(1:2)], col="red")

## A bivariate example
if(requireNamespace("interp")){
  if(requireNamespace("interp")){
    data(CobarOre)
    fCO <- rqss(z ~ qss(cbind(x,y), lambda= .08), data=CobarOre)
    plot(fCO)
  }}

sessionInfo()