| function {base} | R Documentation |
These functions provide the base mechanisms for defining new functions in the R language.
function( arglist ) expr
return(value)
arglist |
Empty or one or more name or name=expression terms. |
value |
An expression. |
The names in an argument list can be back-quoted non-standard names (see ‘backquote’).
If value is missing, NULL is returned. If it is a
single expression, the value of the evaluated expression is returned.
(The expression is evaluated as soon as return is called, in
the evaluation frame of the function and before any
on.exit expression is evaluated.)
If the end of a function is reached without calling return, the
value of the last evaluated expression is returned.
Prior to R 1.8.0, value could be a series of non-empty
expressions separated by commas. In that case the value
returned is a list of the evaluated expressions, with names set to
the expressions where these are the names of R objects. That is,
a=foo() names the list component a and gives it the value
which results from evaluating foo().
This has been deprecated (and a warning is given), as it was never
documented in S, and whether or not the list is named differs by S
versions. Supply a (named) list value instead.
Becker, R. A., Chambers, J. M. and Wilks, A. R. (1988) The New S Language. Wadsworth & Brooks/Cole.
args and body for accessing the arguments
and body of a function.
debug for debugging; using invisible inside
return(.) for returning invisibly.
norm <- function(x) sqrt(x%*%x)
norm(1:4)
## An anonymous function:
(function(x,y){ z <- x^2 + y^2; x+y+z })(0:7, 1)