plot.cobs: Plot Method for COBS Objects

Description

The plot method for cobs objects. If there was lambda selection, it provides two plots by default.

Usage

# S3 method for cobs
plot(x, which = if(x$select.lambda) 1:2 else 2,
     show.k = TRUE,
     col = par("col"), l.col = c("red","pink"), k.col = gray(c(0.6, 0.8)),
     lwd = 2, cex = 0.4, ylim = NULL,
     xlab = deparse(x$call[[2]]),
     ylab = deparse(x$call[[3]]),
     main = paste(deparse(x$call, width.cutoff = 100), collapse="\n"),
     subtit= c("choosing lambda", "data & spline curve") , ...)

Arguments

x: object of class cobs.
which: integer vector specifying which plots should be drawn;

show.k: logical indicating if the “effective dimensionality” \(k\) should also be shown. Only applicable when which contains 1.
col, l.col, k.col: colors for plotting; k.col only applies when show.k is true in the first plot (which == 1) where l.col[2] and k.col[2] are only used as well, for denoting “doubtful” points; col is only used for the 2nd plot (which == 2).
lwd, cex: line width and point size for the 2nd plot (i.e. which == 2).
ylim: y-axis limits, see axis, with a smart default.
xlab, ylab, main: axis annotation; see also axis.
subtit: a vector of length 2, specifying a sub title for each plot (according to which).
...: further arguments passed and to internal plot methods.

Author

Martin Maechler

Details

plot(.) produces two side-by-side plots in case there was a search for the optimal lambda(which = 1:2), and only the (second) data plus spline curve plot otherwise (which = 2).

Examples

Run this code

example(cobs)

plot(Sbs)
plot(fitted(Sbs), resid(Sbs),
     main = "Tukey-Anscombe plot for cobs()",
     sub = deparse(Sbs$call))