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)
‘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:
- To record the call for later re-use: for example most model-fitting functions record the call as element
callof the list they return. Here the default
expand.dots = TRUEis appropriate.
- To pass most of the call to another function, often
model.frame. Here the common idiom is that
expand.dots = FALSEis used, and the
...element of the matched call is removed. An alternative is to explicitly select the arguments to be passed on, as is done in
match.call outside a function without specifying
definition is an error.
An object of class
Chambers, J. M. (1998) Programming with Data. A Guide to the S Language. Springer.
Documentation reproduced from R 3.0.1. License: GPL-2.