Just store them as strings in the data frame and then perform a conversion to expressions prior to the loop:
DF <- data.frame(s = c("O[3]", "NO", "NO[2]"), stringsAsFactors = FALSE) e <- parse(text = DF$s) ... continue with prior solution ... On 12/20/06, MrJ Man <[EMAIL PROTECTED]> wrote: > Thanks for your response; one more thing: Is it > possible to use a data.frame > for the same effect, as these values are associated > with some others (I could > of course use them separately, but merging them in a > data.frame should be > possible in R)? > > > Try this: > > > > > > e <- expression(O[3], NO, NO[2]) > > opar <- par(mfrow = c(2,2)) > > for(i in 1:3) plot(1, 1, type = "b", main = > bquote(.(e[[i]]) ~ Year ~ > > 2005)) par(opar) > > > > Also please read the last line to every post to > r-help and particularly > > note the part about reproducible examples. x and > y.were undefined. > > > > > __________________________________________________ > Do You Yahoo!? > Tired of spam? Yahoo! Mail has the best spam protection around > http://mail.yahoo.com > ______________________________________________ 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.