Much thanks to everyone for their recommendations! I agree that fishing in the global environment isn't ideal & only shows my budding understanding of R.
For now, I will adapt Chel Hee's "length(eval(parse(text=DFName))[,1])" solution then fully explore Jeff's suggestion to put the data frames into a list. At best, I am implementing an ineloquent approach to: (1) Add a column to each data frame with a string that is parsed from the appendage of the data frame name, i.e., string is "1001" from data frame object of "df.1001"; then, (2) Bind the rows of all the files. Any more feedback will be much appreciated! Cheers, Alan On Jan 29, 2015, at 3:11 AM, peter dalgaard wrote: > > On 29 Jan 2015, at 07:34 , Jeff Newmiller <jdnew...@dcn.davis.ca.us> wrote: > >> This approach is fraught with dangers. >> >> I recommend that you put all of those data frames into a list and have your >> function accept the list and the name and use the list indexing operator >> mylist[[DFName]] to refer to it. Having functions that go fishing around in >> the global environment will be hard to maintain at best, and buggy at worst. > > Agreed. However, just to help understand the issue: > > DFName is a length-one vector of character strings, not the object that has > the name contained in the string. I.e. you can do nchar(DFName) and > presumably get the value 7, but there is no operation on df.1001 that can > tell you the length of its name. You can (but shouldn't, as per Jeff's note) > get from name to object using get()/assign() and also via some concoctions > involving combinations of eval(), parse(), as.name(), and substitute(). > > -- > Peter Dalgaard, Professor, > Center for Statistics, Copenhagen Business School > Solbjerg Plads 3, 2000 Frederiksberg, Denmark > Phone: (+45)38153501 > Email: pd....@cbs.dk Priv: pda...@gmail.com > > > > > > > > ______________________________________________ R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see 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.
