The function is used to document plots produced during a data
analysis. It is called by all plotting functions of this package.
For getting final presentation versions of the plots, the stamp can be
suppressed by changing the default by calling options(stamp=0)
.
In more detail: If stamp==0
(or options("stamp")==0
)
the function will only do its thing if sure==TRUE
.
If stamp==2
, it will certainly do it.
If stamp==1
and sure==FALSE
, the stamp is added when a
plot page is complete.