On Tue, Jul 24, 2018 at 11:41 AM, Ista Zahn <istaz...@gmail.com> wrote: > I don't think it has much to do with transform in particular: > >> BOD <- data.frame(Time = 1:6, demand = runif(6)) >> BOD[["X"]] <- BOD[1:2] * seq(6); BOD > Time demand X.Time X.demand > 1 1 0.8649628 1 0.8649628 > 2 2 0.5895380 4 1.1790761 > 3 3 0.6854635 9 2.0563906 > 4 4 0.4255801 16 1.7023206 > 5 5 0.5738793 25 2.8693967 > 6 6 0.9996713 36 5.9980281 >> BOD <- data.frame(Time = 1:6, demand = runif(6)) >> BOD[["X"]] <- BOD[1] * seq(6); BOD > Time demand Time > 1 1 0.72990231 1 > 2 2 0.61721422 4 > 3 3 0.02389160 9 > 4 4 0.28341746 16 > 5 5 0.06116124 25 > 6 6 0.67966577 36
Ugh, well, I see now that BOD[["X"]] <- BOD[1:2] * seq(6); BOD and transform(BOD, X = BOD[1:2] * seq(6)) don't produce the same thing, despite printing in ways that look similar. However, data.frame(BOD, X = BOD[1:2] * seq(6)) and data.frame(BOD, X = BOD[1] * seq(6)) do produce the same result as transform, so the point about this being much more pervasive still holds. --Ista > > --Ista > > > On Tue, Jul 24, 2018 at 7:59 AM, Gabor Grothendieck > <ggrothendi...@gmail.com> wrote: >> 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 ______________________________________________ R-devel@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-devel
