Thanks to all for the help. I found that write.table works nicely, with col.names = FALSE with append = TRUE.
Sincerely, Erin Erin Hodgess, PhD mailto: erinm.hodg...@gmail.com On Thu, Jun 4, 2020 at 7:56 PM Jeff Newmiller <jdnew...@dcn.davis.ca.us> wrote: > Use write.table. > > Write.csv follows a very specific definition for csv... one element of > which is that it is not allowed to have a second header line after data > lines. The only way for write.csv to enforce this is to disallow appending. > > On June 4, 2020 6:34:14 PM PDT, 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. > > -- > Sent from my phone. Please excuse my brevity. > [[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.