vector(mode = "logical", length = 0) as.vector(x, mode = "any") is.vector(x, mode = "any")
vector produces a vector of the given length and mode. Logical
vector elements are initialized to FALSE, numeric vector
elements to 0 and character vector elements to "".
as.vector attempts to coerce its argument into a vector of mode
mode (the default is to coerce to whichever mode is most
convenient). The attributes of x are removed.
is.vector returns TRUE if x is a vector (of mode
logical, factor, integer, real or character) and FALSE
otherwise.