On 03/11/2010 2:05 PM, ivo welch wrote:
quick programming questions. I want to "turn on" more errors. there are two traps I occasionally fall into.* I wonder why R thinks that a variable is always defined in a data frame. > is.defined(d) [1] FALSE > d= data.frame( x=1:5, y=1:5 ) > is.defined(d$z) [1] TRUE > is.defined(nonexisting$garbage) [1] TRUE this is a bit unfortunate for me, because subsequent errors become less clear. right now, I need to do '(is.defined(d) and !is.null(d$z))' to check that my function inputs are valid. It would be nicer if one could just write "if (is.defined(d$z)". * is there a way to turn off automatic recycling? I would rather get an error than unexpected recycling. I can force recycling with rep() when I need to.
Where did you find the is.defined() function? It's not part of R. The R function to do that is exists().
Duncan Murdoch ______________________________________________ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
