> On 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.
The attribute comes from the name of the argument to `apply` > > 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)) The `rbind` function is returning a matrix and `[[<-. data.frame` is adding it to the tdata object. Matrices have dimname attributes. It appears to me that you have also earlier attempted (successfully) to add a column named "OpenInt" higher up in your code that you have not shown us. If you want to get rid of this column use `[<-.data.frame` with a NULL argument tdata['OpenInt'] <- NULL If you start again with neither of these columns, I would suggest this instead: tdata[["newcol2"]] <- c( 0, apply(tdata["Open"],2,diff ) ) The valued returned should be an undimensioned object and will not get bound to the dataframe as a matrix. -- David. > >> 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. David Winsemius Alameda, CA, USA ______________________________________________ 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.
