yikes. this is all my fault. it was the first thing that I ever defined when I started using R.
is.defined <- function(name) exists(as.character(substitute(name))) I presume there is something much better... /iaw On Wed, Nov 3, 2010 at 2:12 PM, Erik Iverson <er...@ccbr.umn.edu> wrote: > > > 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 > > Which package/version of R is the 'is.defined' function in? > > I don't seem to have it here on 2.11.1, which I know is not > the latest version of R. > > What does 'defined' mean? > >> >> 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)". > > "z" %in% names(d) ? > >> >> * 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. >> >> regards, >> >> /iaw >> >> ---- >> Ivo Welch (ivo.we...@brown.edu, ivo.we...@gmail.com) >> >> ______________________________________________ >> 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. > ______________________________________________ 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.
