good practice for values not provided
One possibility is: f <- function(a, b, x) if (missing(x)) a+b else a-b-x although that does have the disadvantage that one cannot explicitly tell it not to use x but rather its denoted by its absence.
On 11/19/06, Tamas K Papp <tpapp at princeton.edu> wrote:
Hi,
I am writing a collection of functions which I plan to share as a
package later (when they are tested thoroughly), so I would like to do
things "right" from the beginning...
I encountered a minor question of style. Consider a function
f <- function(a,b,x=NULL) {
## ...
}
if !is.null(x), f will use x to calculate the result, but if
is.null(x), it will do something else not involving x at all (using
any x would be meaningless here, so I can't use
x=calcsomethingfrom(a,b)).
What's the accepted way of indicating this in R with a default for x?
x=FALSE? x=NA? x=NULL?
Thanks,
Tamas
______________________________________________ R-devel at r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-devel