strip.default(x, level, style = 1,
strip.names = is.shingle(x), name="", bg, fg,
par.strip.text)x.x is a factor. Determines how the current
level of x is indicated on the strip. Details later. Note
that unlike S-Plus the default value is 1.style=2 and 4 when x is a factor.col, cexstyle argument --- non-default styles
are often more informative, especially when the names of the levels
of the factor x are small. Typical use is as
strip = function(...) strip.default(style=2,...)trellis.args, Lattice