match.call {base} | R Documentation |
match.call
returns a call in which all of the specified arguments are
specified by their full names.
match.call(definition = NULL, call = sys.call(sys.parent()), expand.dots = TRUE)
definition |
a function, by default the function from which
match.call is called. |
call |
an unevaluated call to the function specified by
definition , as generated by call . |
expand.dots |
logical. Should arguments matching ...
in the call be included or left as a ... argument? |
match.call
is most commonly used in two circumstamces:
call
of
the list they return. Here the default expand.dots = TRUE
is appropriate.
model.frame
. Here the common idiom is that
expand.dots = FALSE
is used, and the ...
elememt
of the matched call is removed. An alternative is to
explicitly select the arguments to be passed on, as is done in
lm
.
An object of class call
.
Chambers, J. M. (1998) Programming with Data. A Guide to the S Language. Springer.
call
, pmatch
, match.arg
,
match.fun
.
match.call(get, call("get", "abc", i = FALSE, p = 3)) ## -> get(x = "abc", pos = 3, inherits = FALSE) fun <- function(x, lower = 0, upper = 1) { structure((x - lower) / (upper - lower), CALL = match.call()) } fun(4 * atan(1), u = pi)