This help topic is for R version 0.60. For the current version of R, try https://stat.ethz.ch/R-manual/R-patched/library/base/html/call.html
call {base}R Documentation

Function Calls

Usage

call(name, ...)

is.call(expr)
as.call(expr)

Value

An unevaluated function call, that is, an unevaluated expression which consists of the named function applied to the given arguments (name must be a quoted string which gives the name of a function to be called).

is.call is used to determine whether expr is a call. We don't differentiate between expressions and function calls. So is.call is the same as is.expression.

It is not possible to coerce objects to mode call (objects either are calls or they are not calls). as.call returns its argument if it is a call and otherwise terminated with an error message.

See Also

expression, function.

Examples

is.call(call) #-> FALSE: Functions are NOT calls

# set up a function call to round with argument 10.5
cl <- call("round",10.5)
cl
# such a call can also be evaluated.
eval(cl)# [1] 10

[Package base version 0.60 ]