On Jul 15, 2012, at 17:41 , Paulo Barata wrote: > > Dr. Dalgaard, > > Thank you. But pre-checking with is.null() or using with() > doesn't solve the problem of catching spelling mistakes > in the name of a variable inside a data frame, when using > the df$var notation often in a program. > > Is there some way for R to behave, in relation to a variable > inside a data frame, the same way it behaves for a variable > not in a data frame? For example:
You could try reading the 2nd half of my one-line reply.... >> >> You can pre-check for is.null(df$aaa) or use with(df, sum(aaa==2)). -- 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 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.
