Will you be doing the same for attribute names? > 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". 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 ______________________________________________ R-devel@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-devel
