There we go, thank you! On Fri, Feb 4, 2011 at 11:42 AM, Jeff Ryan <jeff.a.r...@gmail.com> wrote:
> 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 > [[alternative HTML version deleted]] ______________________________________________ R-devel@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-devel
