Hi, You don't provide a reproducible example, but I suspect what you need is parse():
> parse(text = "A + B") expression(A + B) Sarah On Thu, Mar 15, 2012 at 10:55 AM, capy_bara <hettl...@few.vu.nl> wrote: > Dear all, > > I am confused about how to create an expression. I use a package (rsbml) > which uses expressions and seems to make a difference if there is a quote > around the expression or not. > > For example, package works with expressions such as >> expression(A + B) > but not with >> expression("A + B") > > I now have a set of math expressions represented as strings, something like > this: >> rhs_eq<- c("0", "A + B", "B * (2+C)") > and want to make expressions without quotes out of it. > > I tried >> lapply(lapply(rhs_eq, as.symbol), as.expression) > which only turns the double quotes into single quotes, but does not remove > the quotes. > I also played around with as.formula, as.name, quote and enquote, but had no > success. > > Does anyone know about quotes in the expression data type? > > Thanks in advance, > > Hannes > > -- Sarah Goslee http://www.functionaldiversity.org ______________________________________________ R-help@r-project.org 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.