Patrick, Take a look at all.vars to start with That will return the vars as characters, from there you can use get to test/proceed.
> all.vars(parse.tree) [1] "x" Best, Jeff On Fri, Feb 4, 2011 at 1:37 PM, Patrick Leyshock <ngkbr...@gmail.com> wrote: > Hello, > > I'm trying to access an object, given only its name as a symbol. I cannot > figure out how to proceed. Suppose I call substitute( ) on the expression > 'x + 2': > >> parse.tree <- substitute(x + 2); > > The constituents of parse.tree are of type symbol and numeric: > >> str(parse.tree[[1]]) > symbol + > >> str(parse.tree[[2]]) > symbol x > >> str(parse.tree[[3]]) > num 2 > > Suppose that x is S4 object, and that I need to access a slot of that > object. How can I do so, using only 'parse.tree' (or parse.tree coerced > into a list)? > > Thanks, Patrick > > [[alternative HTML version deleted]] > > ______________________________________________ > R-devel@r-project.org mailing list > https://stat.ethz.ch/mailman/listinfo/r-devel > -- Jeffrey Ryan jeffrey.r...@lemnica.com www.lemnica.com ______________________________________________ R-devel@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-devel
