On Mar 20, 2013, at 16:59 , William Dunlap wrote: > Will you be doing the same for attribute names?
Not at this point. > >> options(prompt=with(version, paste0(language,"-",major,".",minor,"> "))) > R-2.15.3> x <- structure(17, AnAttr="an attribute", Abcd="a b c d") > R-2.15.3> attr(x, "A") > NULL > R-2.15.3> attr(x, "An") > [1] "an attribute" > R-2.15.3> attr(x, "Ab") > [1] "a b c d" > > How will you deal with the common idiom of using is.null(x$n) > to see if x has a compnent named "n"? One would not want > a warning if x had a component called "nn". Why not? If you were looking for x$n, you're getting the wrong answer. > > Bill Dunlap > Spotfire, TIBCO Software > wdunlap tibco.com > > >> -----Original Message----- >> From: r-devel-boun...@r-project.org [mailto:r-devel-boun...@r-project.org] >> On Behalf >> Of peter dalgaard >> Sent: Wednesday, March 20, 2013 5:28 AM >> To: r-devel@r-project.org >> Subject: [Rd] Deprecating partial matching in $.data.frame >> >> Allowing partial matching on $-extraction has always been a source of >> accidents. >> Recently, someone who shall remain nameless tried names(mydata) <- "d^2" >> followed by >> mydata$d^2. >> >> As variables in a data frame are generally considered similar to variables >> in, say, the >> global environment, it seems strange that foo$bar can give you the content of >> foo$bartender. >> >> In R-devel (i.e., *not* R-3.0.0 beta, but 3.1.0-to-be) partial matches now >> gives a warning. >> >> Of course, it is inevitable that lazy programmers will have been using code >> like >> >>> anova(fit1)$P >> [1] 0.0008866369 NA >> Warning message: >> In `$.data.frame`(anova(fit1), P) : Name partially matched in data frame >> >> and now get the warning during package checks. This can always be removed by >> spelling >> out the column name, as in >> >>> anova(fit1)$`Pr(>F)` >> [1] 0.0008866369 NA >> >> or by explicitly specifying a partial match with >> >>> anova(fit1)[["P", exact=FALSE]] >> [1] 0.0008866369 NA >> >> >> -- >> 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-devel@r-project.org mailing list >> https://stat.ethz.ch/mailman/listinfo/r-devel -- 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-devel@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-devel
