This help topic is for R version 2.9.0. For the current version of R, try https://stat.ethz.ch/R-manual/R-patched/library/base/html/match.call.html
match.call {base}R Documentation

Argument Matching

Description

match.call returns a call in which all of the specified arguments are specified by their full names.

Usage

match.call(definition = NULL, call = sys.call(sys.parent()),
           expand.dots = TRUE)

Arguments

definition

a function, by default the function from which match.call is called. See details.

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?

Details

‘function’ on this help page means an interpreted function (also known as a ‘closure’): match.call does not support primitive functions (where argument matching is normally positional).

match.call is most commonly used in two circumstances:

Calling match.call outside a function without specifying definition is an error.

Value

An object of class call.

References

Chambers, J. M. (1998) Programming with Data. A Guide to the S Language. Springer.

See Also

sys.call() is similar, but does not expand the argument names; call, pmatch, match.arg, match.fun.

Examples

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)

[Package base version 2.9.0 ]