match.call               package:base               R Documentation

Argument Matching

Description:

     'match.call' returns a call in which all of the arguments are
     specified by their names.  The most common use is to get the call
     of the current function, with all arguments named.

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.

    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?

Value:

     An object of class 'call'.

References:

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

See Also:

     '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)

