Hi Erin: The default for write.csv is col.names = TRUE . So, in the second one, if you put, col.names = FALSE, that should work. It's confused right now because you want to append but also write the column names again.
Mark On Thu, Jun 4, 2020 at 9:34 PM Erin Hodgess <erinm.hodg...@gmail.com> wrote: > Hello! > > Hope everyone is doing as well as possible. > > I have a question about write.csv. I thought that the append argument > would permit adding another data frame with the same column names. > > Here is my example: > > date1 <- as.Date("2020-03-09") > wday <- weekdays(date1) > x1 <- data.frame(date=date1,day=wday,lev=1:5,y=rnorm(5)) > x1 > date day lev y > 1 2020-03-09 Monday 1 -0.09543049 > 2 2020-03-09 Monday 2 0.53943428 > 3 2020-03-09 Monday 3 -0.79224851 > 4 2020-03-09 Monday 4 0.68168147 > 5 2020-03-09 Monday 5 -1.02902897 > write.csv(file="test1.csv",x1,row.names=FALSE) > date1 <- date1 + 1 > wday <- weekdays(date1) > x2 <- data.frame(date=date1,day=wday,lev=1:5,y=rnorm(5)) > x2 > date day lev y > 1 2020-03-10 Tuesday 1 -0.6648301 > 2 2020-03-10 Tuesday 2 -0.1137580 > 3 2020-03-10 Tuesday 3 1.6532675 > 4 2020-03-10 Tuesday 4 -0.5845293 > 5 2020-03-10 Tuesday 5 0.2849392 > write.csv(file="test1.csv",x2,row.names=FALSE,append=TRUE) > Warning message: > In write.csv(file = "test1.csv", x2, row.names = FALSE, append = TRUE) : > attempt to set 'append' ignored > > The values from x2 appear in the test1.csv file. > > What am I missing, please? > > Thanks, > Erin > > > Erin Hodgess, PhD > mailto: erinm.hodg...@gmail.com > > [[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.