On Aug 27, 2014, at 12:44 PM, Gang Chen wrote: > Thanks for the help! However, I just need to get > > pdCompSymm(~1 + Age)
That's not a formula in the R sense of the word. You should do a better job of posting a use case. Perhaps you want an expression? -- David. > > without a tilde (~) at the beginning. > > On Wed, Aug 27, 2014 at 3:34 PM, David Winsemius <dwinsem...@comcast.net> > wrote: >> >> On Aug 27, 2014, at 11:19 AM, Gang Chen wrote: >> >>> A random effect formulation for R package nlme is read in as a string >>> of characters from an input file: >>> >>> ranEff <- "pdCompSymm(~1+Age)" >>> >>> I need to convert 'ranEff' to a formula class. However, as shown below: >>> >>>> as.formula(ranEff) >>> ~1 + Age >>> >>> the "pdCompSymm" is lost in the conversion. Any solutions? >> >> as.formula(paste("~",ranEff)) >> ~pdCompSymm(~1 + Age) >> -- >> >> David Winsemius >> Alameda, CA, USA >> David Winsemius Alameda, CA, USA ______________________________________________ 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.