unsplit method for List object and split<-
method for Vector object.
"unsplit"(value, f, drop = FALSE)
"split"(x, f, drop = FALSE, ...) <- valuefactor or list of factors
X
FUN
unsplit unlists value, where the order of the returned
vector is as if value were originally created by splitting that
vector on the factor f. split(x, f, drop = FALSE) <- value: Virtually splits x by
the factor f, replaces the elements of the resulting list with the
elements from the list value, and restores x to its original
form. Note that this works for any Vector, even though split
itself is not universally supported.