Thanks Duncan, I knew that, I wanted to know if there was some way not involving having to recreate the df. It is not a big issue in this case (they are not very big), but it might be problematic for big data frames.
Thanks for advice on using col.names=NA. Cheers, Luca Luca Cerone Tel: +34 692 06 71 28 Skype: luca.cerone On Wed, Mar 19, 2014 at 11:44 AM, Duncan Murdoch <murdoch.dun...@gmail.com> wrote: > On 14-03-19 6:12 AM, Luca Cerone wrote: >> >> Hi everybody, >> I am sorry if this is a silly question (I have tried to search it at >> http://tolstoy.newcastle.edu.au/R/ but I get a 404 page). >> >> I have a script writing some data.frames to csv files. >> I write the csv files using the write.csv function and the option >> row.names=TRUE. >> Everything works fine, except that I am not able to set the name of >> the column holding the row.names. >> >> For example I tried to set the column name to ID like this: >> >> df = data.frame(a=c(1,2,3), b=c(3,4,5)) >> rownames(df) = c("A","B","C") >> >> write.csv(df, row.names=TRUE, colnames=c("ID", colnames(df))) >> >> This fails with the following error: >> Error in write.table(df, row.names = TRUE, colnames = c("ID", >> colnames(df)), : >> unused argument (colnames = c("ID", colnames(df))) >> >> How can I do this? I have tried to use write.table() as well, but it >> seems I never get to set the options right. >> > > You can't get a column heading for the row names. If you want a blank entry > there, use col.names=NA and row.names=TRUE. If you want the heading to be > ID, then you need to write the row names as a regular column of the > dataframe, e.g. > > df2 <- data.frame(ID=rownames(df), df) > > and then write df2 *without* rownames (so they don't appear twice). > > Duncan Murdoch ______________________________________________ R-help@r-project.org mailing list 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.
