'v' appears to be a list: > v=c(`-`,`+`,1,`^`,`^`,NA,NA,"X",9,"X",2) > i2=16 > v[i2] [[1]] NULL
> str(v) List of 11 $ :function (e1, e2) $ :function (e1, e2) $ : num 1 $ :function (e1, e2) $ :function (e1, e2) $ : logi NA $ : logi NA $ : chr "X" $ : num 9 $ : chr "X" $ : num 2 because you used backquotes(`) on the '-'; notice the difference: > str(c(`-`,1)) List of 2 $ :function (e1, e2) $ : num 1 > str(c('-',1)) chr [1:2] "-" "1" > On 7/12/07, Atte Tenkanen <[EMAIL PROTECTED]> wrote: > Hi, > > What's wrong here?: > > > v=c(`-`,`+`,1,`^`,`^`,NA,NA,"X",9,"X",2) > > i2=16 > > v[i2] > [[1]] > NULL > > > is.null(v[i2]) > [1] FALSE > > Is it a bug or have I misunderstood something? > > Atte Tenkanen > University of Turku, Finland > > ______________________________________________ > R-help@stat.math.ethz.ch 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. > -- Jim Holtman Cincinnati, OH +1 513 646 9390 What is the problem you are trying to solve? ______________________________________________ R-help@stat.math.ethz.ch 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.