Use xx[[gene]] instead of xx$gene (the $ is a shorthand for [[ with some extra magic to be more convenient, the magic is getting in your way, so go back to the [[ syntax (make sure you double the braces)).
Hope this helps, -- Gregory (Greg) L. Snow Ph.D. Statistical Data Center Intermountain Healthcare [EMAIL PROTECTED] (801) 408-8111 > -----Original Message----- > From: [EMAIL PROTECTED] > [mailto:[EMAIL PROTECTED] On Behalf Of rosa clements > Sent: Thursday, July 12, 2007 11:39 AM > To: r-help@stat.math.ethz.ch > Subject: [R] Interpreting a string as a variable in a column header > > This must be a very simple question, but I can't find any > information on it elsewhere, sorry. When extracting > information from a list using column headers, how do I get R > to interpret something as a variable rather than a string? > For example: > > xx$"YAL002" > > works, but this doesn't: > > gene <- "YAL002" > xx$gene > > neither do > > xx$parse(gene) > xx$eval(gene) > xx$eval(parse(gene)) > > or a variety of other constructions I have tried. > > Background: I have a table of information about yeast genes, > and I also have a list of yeast genes and their GO terms (xx) > from the YEAST package that I downloaded. I want to go > through all the genes in my table and look up their GO terms > in the list from the YEAST package. > They might not contain exactly the same genes (ideally they > should, but I'd be surprised if they do) and I don't think > they're in the same order, so I do want to use the column > names, but there are a lot of them so I'm not typing them all > out individually. It might be possible to turn the GO data > into something other than a list, but the help page > recommends using xx <- as.list(YEASTGO) and doesn't make any > other suggestions, so I should probably do as I'm told. > > Thanks for any help or suggestions of where to look, > > Rosa > > ______________________________________________ > 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. > ______________________________________________ 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.