| is.recursive {base} | R Documentation |
is.atomic returns TRUE if x is an atomic vector
(or NULL) and FALSE otherwise.
is.recursive returns TRUE if x has a recursive
(list-like) structure and FALSE otherwise.
is.atomic(x) is.recursive(x)
x |
object to be tested. |
is.atomic is true for the atomic vector types
("logical", "integer", "numeric",
"complex", "character" and "raw") and NULL.
Most types of objects are regarded as recursive, except for
atomic vector types, NULL and symbols (as given by
as.name).
These are primitive functions.
Becker, R. A., Chambers, J. M. and Wilks, A. R. (1988) The New S Language. Wadsworth & Brooks/Cole.
is.list,
is.language, etc,
and the demo("is.things").
require(stats) is.a.r <- function(x) c(is.atomic(x), is.recursive(x)) is.a.r(c(a=1,b=3)) # TRUE FALSE is.a.r(list()) # FALSE TRUE - a list is a list is.a.r(list(2)) # FALSE TRUE is.a.r(lm) # FALSE TRUE is.a.r(y ~ x) # FALSE TRUE is.a.r(expression(x+1)) # FALSE TRUE (nowadays)