Re: [R] Testing for existence of object within a function

On Fri, Oct 8, 2010 at 4:05 PM, Eli Holmes wrote: > I'm still trying to sort out if I can tell the function not to use > values in the user workspace if they don't exist locally in a > function, i.e. a "use local variables only" option when defining a > function. Obviously, I could go to a style o

Re: [R] Testing for existence of object within a function

Thanks for the help. After looking over the answers, I've come up with some revised code: # To simply test if an argument was passed in, missing() can be used # However, if arg defined later, missing() will return TRUE instead of false a=1 #put a in global environment tst <- function(a,b=1) { if

Re: [R] Testing for existence of object within a function

On Oct 7, 2010, at 7:27 PM, Eli Holmes wrote: I'm trying to test for the existence of an object within a function, but despite searching the help files and R-list, I can't figure out how to do it. Here is some test code: #- a=1 #now I have a in the global environment

Re: [R] Testing for existence of object within a function

Eli - I think you're looking for missing(): tst = function(a,b=1) + if(missing(a))print("You must provide a") else print(a) tst() [1] "You must provide a" tst(7) [1] 7 - Phil Spector Statistical Co