sprm (version 1.1)

biplot.prm: Biplot for prm objects

Description

This biplot for prm objects visualizes the original variables which contribute to the model and their impact on the latent components as well as the position of the observations in the transformed space. The data is projected onto two of the latent components.

Usage

## S3 method for class 'prm':
biplot(x, comps = c(1, 2), 
colors = list(scores = "#0000AA", loadings = "red", background = "#BBBBEE"), 
textsize = 6, arrowshapes = c(25, 0.03), ...)

Arguments

x

object of class prm.

comps

vector with two integers, referring to the components to be plotted.

colors

list of three elements named scores, loadings and background with color codes or names.

textsize

the text size in which to print the scores and loading names.

arrowshapes

vector of length two containing the angle of the arrowheads and their relative length in npc.

...

further arguments. Currently not used.

References

Sven Serneels et al. (2014) Sparse partial robust M regression

Serneels, S., Croux, C., Filzmoser, P., Van Espen, P.J., Partial Robust M-Regression. Chemometrics and Intelligent Laboratory Systems, 79 (2005), 55-64.

See Also

plot.prm, prms, biplot.sprm

Examples

set.seed(5023)
U <- c(rep(3,20), rep(4,30))
X <- replicate(6, U+rnorm(50))
beta <- c(rep(1, 3), rep(-1,3))
e <- c(rnorm(45,0,1.5),rnorm(5,-20,1))
y <- X%*%beta + e
d <- as.data.frame(X)
d$y <- y
mod <- prms(y~., data=d, a=2, fun="Hampel")
biplot(mod, comps = c(1, 2))