fac.design.
Primarily designed for use with
Subscript.
is.fac.design(x)
is.fac.design tests whether
x is a
fac.design object.
That is, it returns
TRUE if
x satisfies a condition for
fac.design
and
FALSE otherwise.
The testing is not exhaustive, and does not guarantee that
x
satisfies all of the properties (loosely) required of a
fac.design object.