cex for variable names.
Default is 1.
Make smaller (say 0.8) if you have lots of variables.
type.nsubsets
Plot type for nsubsets graph.
Default is "l".
Use "n" for none, "b" looks good too.
col.nsubsets
Color of nsubsets line.
Default is "black".
lty.nsubsets
Line type of nsubsets line.
Default is 1.
type.gcv,col.gcv,lty.gcv
As above but for the gcv plot
type.rss,col.rss,lty.rss
As above but for the rss plot
cex.legend
cex for legend strings.
Default is 1.
Make smaller (say 0.8) if you want a smaller legend.
x.legend
x position of legend.
Use 0 for no legend.
y.legend
y position of legend.
rh.col
Color of right hand axis label. Use rh.col=0 for no label,
a workaround for when the label is mispositioned.
do.par
Call par() for global settings as appropriate.
Default is TRUE, which sets
oma=c(bottom.margin,0,0,3), cex=cex.var.
Set to FALSE if you want to append figures to an existing plot.