The character vector
gam.slist has by default the values
c("s", "lo","random")
. This supplies
gam() with a set of
smoothers that are
available, that have been properly interfaced with the
gam() fitting
algorithms. Thus since
"s" is in this list, then all terms of the
form
s(age) in a formula will be designated as
"special" by the
function
terms(), and indicate that a smoother is available for
smoothing against its argument. An entry in this vector, say
"s",
implies the presence of a function
glm.s().
The vector
gam.wlist is currently initialized to
c("s","lo"), and
indicates what special, efficient backfitting algorithms are available
when all the terms in the additive model are to be fit with the same
type of smoother. An entry, say
"s", in this table indicates the
presence of a function
s.wam().