[R] if/else help
macqueen1 at llnl.gov
Wed Sep 21 17:26:11 CEST 2016
Hopefully this is not a homework question.
The other responses are fine, but I would suggest the simplest way to do
exactly what you ask is
if (!exists('r4')) r4 <- data.frame(a=0, b=0, c=0, d='x')
The exists() function requires a character string for its first argument,
i.e., the name of the object, not the object itself (check the help page
Using "get" to get it doesn't make sense if it already exists.
Lawrence Livermore National Laboratory
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On 9/20/16, 12:31 PM, "R-help on behalf of Crombie, Burnette N"
<r-help-bounces at r-project.org on behalf of bcrombie at utk.edu> wrote:
>If a data.frame (r4) does not exist in my R environment, I would like to
>create it before I move on to the next step in my script. How do I make
>that happen? Here is what I want to do from a code perspective:
>a <- 0, b <- 0, c <- 0, d <- "x", r4 <- data.frame(cbind(a,b,c,d))
>Thanks for your help,
> [[alternative HTML version deleted]]
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