You could use transform() instead of [[<- to add columns to your data.frame so the new columns get transformed they way they do when given to the data.frame function itself. E.g.,
> dd <- data.frame(X=1:5, Y=11:15) > str(transform(dd, Z=matrix(X+Y,ncol=1,dimnames=list(NULL, "NewZ")))) 'data.frame': 5 obs. of 3 variables: $ X : int 1 2 3 4 5 $ Y : int 11 12 13 14 15 $ NewZ: int 12 14 16 18 20 > str(transform(dd, Z=matrix(c(X,Y),ncol=2,dimnames=list(NULL, c("NewZ1","NewZ2"))))) 'data.frame': 5 obs. of 4 variables: $ X : int 1 2 3 4 5 $ Y : int 11 12 13 14 15 $ Z.NewZ1: int 1 2 3 4 5 $ Z.NewZ2: int 11 12 13 14 15 Bill Dunlap TIBCO Software wdunlap tibco.com On Sat, Apr 23, 2016 at 8:59 AM, thomas mann <twiniverse2...@gmail.com> wrote: > I am attempting to add a calculated column to a data frame. Basically, > adding a column called "newcol2" which are the stock closing prices from 1 > day to the next. > > The one little hang up is the name of the column. There seems to be an > additional data column name included in the attributes (dimnames?). So > when i run HEAD(DATAFRAMENAME) i get the column name = "Open". but you > can see below... it is called "newcol2 with some attribute called open. > > I did a lot of google searches but really could not find what i was looking > for. Any help is greatly appreciated. Thank you! > > tdata[["newcol2"]] <- rbind(0,apply(tdata["Open"],2,diff)) > > > str(tdata) > 'data.frame': 7505 obs. of 8 variables: > $ Date : int 19860709 19860710 19860711 19860714 19860715 19860716 > 19860717 19860718 19860721 19860722 ... > $ Open : num 9.14 9.45 9.3 9.08 8.71 ... > $ High : num 9.45 9.51 9.35 9.08 8.71 ... > $ Low : num 9.03 9.14 9.03 8.65 7.96 ... > $ Close : num 9.4 9.35 9.03 8.76 8.5 ... > $ Volume : int 332719 180049 234212 218772 605427 339507 306866 418593 > 94880 119332 ... > $ OpenInt: num [1:7505, 1] 0 0.317 -0.155 -0.223 -0.367 ... > ..- attr(*, "dimnames")=List of 2 > .. ..$ : NULL > .. ..$ : chr "Open" > * $ newcol2:* num [1:7505, 1] 0 0.317 -0.155 -0.223 -0.367 ... > ..- attr(*, "dimnames")=List of 2 > .. ..$ : NULL > * .. ..$ : chr "Open"* > > [[alternative HTML version deleted]] > > ______________________________________________ > R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see > 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. > [[alternative HTML version deleted]] ______________________________________________ R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see 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.