plot.lmrob: Plot Method for "lmrob" Objects

In robustbase: Basic Robust Statistics

Plot Method for "lmrob" Objects

Description

Diagnostic plots for elements of class lmrob

Usage

## S3 method for class 'lmrob'
plot(x, which = 1:5,
     caption = c("Standardized residuals vs. Robust Distances",
   "Normal Q-Q vs. Residuals", "Response vs. Fitted Values",
   "Residuals vs. Fitted Values" , "Sqrt of abs(Residuals) vs. Fitted Values"),
   panel = if(add.smooth) panel.smooth else points,
   sub.caption = deparse(x$call), main = "",
   compute.MD = TRUE,
   ask = prod(par("mfcol")) < length(which) && dev.interactive(),
   id.n = 3, labels.id = names(residuals(x)), cex.id = 0.75,
   label.pos = c(4,2), qqline = TRUE, add.smooth = getOption("add.smooth"),
   ..., p=0.025)

Arguments

x	an object as created by lmrob
which	integer number between 1 and 5 to specify which plot is desired
caption	Caption for the different plots
panel	panel function. The useful alternative to points, panel.smooth can be chosen by add.smooth = TRUE.
main	main title
sub.caption	sub titles
compute.MD	logical indicating if the robust Mahalanobis distances should be recomputed, using covMcd() when needed, i.e., if which contains 1.
ask	waits for user input before displaying each plot
id.n	number of points to be labelled in each plot, starting with the most extreme.
labels.id	vector of labels, from which the labels for extreme points will be chosen. NULL uses observation numbers.
cex.id	magnification of point labels.
label.pos	positioning of labels, for the left half and right half of the graph respectively.
qqline	logical indicating if a qqline() should be added to the normal Q-Q plot.
add.smooth	logical indicating if a smoother should be added to most plots; see also panel above.
...	optional arguments for par, title, etc.
p	threshold for distance-distance plot

Details

if compute.MD = TRUE and the robust Mahalanobis distances need to be computed, they are stored (“cached”) with the object x when this function has been called from top-level.

References

Robust diagnostic plots as in Rousseeuw and van Zomeren (1990), see ‘References’ in ltsPlot.

See Also

lmrob, also for examples, plot.lm.

Examples

data(starsCYG)
## Plot simple data and fitted lines
plot(starsCYG)
 lmST <-    lm(log.light ~ log.Te, data = starsCYG)
RlmST <- lmrob(log.light ~ log.Te, data = starsCYG)
RlmST
abline(lmST, col = "red")
abline(RlmST, col = "blue")

op <- par(mfrow = c(2,2), mgp = c(1.5, 0.6, 0), mar= .1+c(3,3,3,1))
plot(RlmST, which = c(1:2, 4:5))
par(op)

robustbase documentation built on Sept. 27, 2024, 5:09 p.m.