match.fun(FUN, descend=TRUE)
FUN
|
function, e.g. as passed to outer .
|
descend
| logical; control whether to search under non-function objects. |
FUN
to a function, where FUN
can be a
character (string), e.g., "*"
or "fred"
,
or a function such as pmax
.
Returns an error if no matching function is found.
descend=TRUE
, match.fun
will look underneath
non-function objects with the given name; otherwise if FUN
points to a non-function object then an error is generated.
This is now used in base functions such as
apply
, lapply
, outer
,
sweep
, and the like.
FUN
or an error is generated.FUN
is always matched to a
function, even if there is a non-function object higher up the
search list with the same name.match.arg
# Same as get("*"): match.fun("*") # Overwrite outer with a vector outer <- 1:5 match.fun(outer, descend = FALSE) #-> Error: not a function match.fun(outer) # finds it anyway is.function(match.fun("outer")) # as well