[R] creating function bodies using body()

[Thomas W Blackwell]

Defining a function is much simpler than that:

tmpfun <- function(a, b=2)
 {  z <- a = b
    z^2         }    #  returns (a + b)^2

But maybe you want the advertised syntax to work.  Please
pardon if I've misjudged the depth of your question.  I've
never tried to use  body().

-  tom blackwell  -  u michigan medical school  -  ann arbor  -

On Fri, 4 Apr 2003 Setzer.Woodrow at epamail.epa.gov wrote:

> I'm having trouble figuring out how to create a function using "body<-"
> ().  The help file for body() says that the argument should be a list of
> R expressions.  However if I try that I get an error:
>
> > tmpfun <- function(a, b=2){}
> > body(tmpfun) <- list(expression(z <- a + b),expression(z^2))
> Error in as.function.default(c(formals(f), value), envir) :
>         invalid formal argument list for "function"
>
> Can someone give me a simple example for doing this?  Thanks!
>
> R. Woodrow Setzer, Jr.                        Phone: (919) 541-0128
> Experimental Toxicology Division             Fax:  (919) 541-4284
> Pharmacokinetics Branch
> NHEERL B143-05; US EPA; RTP, NC 27711