The idea is that one wants to write the line of code below in a general way which works the same whether you specify ix as one column or multiple columns but the naming entirely changes when you do this and BOD[, 1] and transform(BOD, X=..., Y=...) or other hard coding solutions still require writing multiple cases.
ix <- 1:2 transform(BOD, X = BOD[ix] * seq(6)) On Tue, Jul 24, 2018 at 7:14 AM, Emil Bode <emil.b...@dans.knaw.nl> wrote: > I think you meant to call BOD[,1] > From ?transform, the ... arguments are supposed to be vectors, and BOD[1] is > still a data.frame (with one column). So I don't think it's surprising > transform gets confused by which name to use (X, or Time?), and kind of > compromises on the name "Time". It's also in a note in ?transform: "If some > of the values are not vectors of the appropriate length, you deserve whatever > you get!" > And if you want to do it with multiple extra columns (and are not satisfied > with these labels), I think the proper way to go would be " transform(BOD, > X=BOD[,1]*seq(6), Y=BOD[,2]*seq(6))" > > If you want to trace it back further, it's not in transform but in > data.frame. Column-names are prepended with a higher-level name if the object > has more than one column. > And it uses the tag-name if simply supplied with a vector: > data.frame(BOD[1:2], X=BOD[1]*seq(6)) takes the name of the only column of > BOD[1], Time. Only because that column name is already present, it's changed > to Time.1 > data.frame(BOD[1:2], X=BOD[,1]*seq(6)) gives third column-name X (as X is now > a vector) > data.frame(BOD[1:2], X=BOD[1:2]*seq(6)) or with BOD[,1:2] gives columns names > X.Time and X.demand, to show these (multiple) columns are coming from X > > So I don't think there's much to fix here. I this case having X.Time in all > cases would have been better, but in general the column-naming of data.frame > works, changing it would likely cause a lot of problems. > You can always change the column-names later. > > Best regards, > Emil Bode > > Data-analyst > > +31 6 43 83 89 33 > emil.b...@dans.knaw.nl > > DANS: Netherlands Institute for Permanent Access to Digital Research Resources > Anna van Saksenlaan 51 | 2593 HW Den Haag | +31 70 349 44 50 | > i...@dans.knaw.nl <mailto:i...@dans.kn> | dans.knaw.nl > <applewebdata://71F677F0-6872-45F3-A6C4-4972BF87185B/www.dans.knaw.nl> > DANS is an institute of the Dutch Academy KNAW <http://knaw.nl/nl> and > funding organisation NWO <http://www.nwo.nl/>. > > On 23/07/2018, 16:52, "R-devel on behalf of Gabor Grothendieck" > <r-devel-boun...@r-project.org on behalf of ggrothendi...@gmail.com> wrote: > > Note the inconsistency in the names in these two examples. X.Time in > the first case and Time.1 in the second case. > > > transform(BOD, X = BOD[1:2] * seq(6)) > Time demand X.Time X.demand > 1 1 8.3 1 8.3 > 2 2 10.3 4 20.6 > 3 3 19.0 9 57.0 > 4 4 16.0 16 64.0 > 5 5 15.6 25 78.0 > 6 7 19.8 42 118.8 > > > transform(BOD, X = BOD[1] * seq(6)) > Time demand Time.1 > 1 1 8.3 1 > 2 2 10.3 4 > 3 3 19.0 9 > 4 4 16.0 16 > 5 5 15.6 25 > 6 7 19.8 42 > > -- > Statistics & Software Consulting > GKX Group, GKX Associates Inc. > tel: 1-877-GKX-GROUP > email: ggrothendieck at gmail.com > > ______________________________________________ > R-devel@r-project.org mailing list > https://stat.ethz.ch/mailman/listinfo/r-devel > > -- Statistics & Software Consulting GKX Group, GKX Associates Inc. tel: 1-877-GKX-GROUP email: ggrothendieck at gmail.com ______________________________________________ R-devel@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-devel
