[R] R equiv of #ifdef?

[Bill Simpson]

I was wondering if R has an equivalent of #ifdef.
I want the code to check if a function has been sourced in yet, and if
not, then source it in. (I know of replace(), which works for
packages/libraries)

Here is what I have come up with.

my.objects<-objects()
if(my.objects[my.objects=="thingy2"]!="thingy2")
	source("~/papers/speed/junk.r")

junk.r contains the code for function thingy2().
This doesn't work: "missing value where logical needed"
The error message puzzles me.

>my.objects[my.objects=="thingy2"]!="thingy2"
logical(0)

Thanks very much for any help.

Bill Simpson

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