Georg One way is to call factor() on the subsetted object.
> georg <- factor(LETTERS[1:4]) > summary(georg) A B C D 1 1 1 1 > georg <- georg[georg!='A'] > summary(georg) # the level is still there A B C D 0 1 1 1 > georg <- factor(georg) > summary(georg) # now it is gone B C D 1 1 1 HTH .... Peter Alspach > -----Original Message----- > From: [EMAIL PROTECTED] > [mailto:[EMAIL PROTECTED] On Behalf Of Georg Ehret > Sent: Wednesday, 23 April 2008 8:58 a.m. > To: r-help > Subject: [R] levels in dataframes > > Dear R community, I wish to ask a short question > concerning factor-data > in dataframes: When I subset the data and get rid of all data > for one level, I still retain the level name (obtained by > levels(dataframe$variablename) ). > Is there a convenient way to get rid of the levels for which > all data has been deleted? > Thank you and wishing you an excellent day! > Georg. > **************************************************** > Georg Ehret > Johns Hopkins > Baltimore, US > > [[alternative HTML version deleted]] > > ______________________________________________ > 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. > The contents of this e-mail are privileged and/or confidential to the named recipient and are not to be used by any other person and/or organisation. If you have received this e-mail in error, please notify the sender and delete all material pertaining to this e-mail. ______________________________________________ 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.
