Tena koe Mark ?tapply
with the index argument some suitable substring of your ID column. HTH .... Peter Alspach > -----Original Message----- > From: r-help-boun...@r-project.org > [mailto:r-help-boun...@r-project.org] On Behalf Of Mark Na > Sent: Friday, 10 July 2009 10:28 a.m. > To: r-help@r-project.org > Subject: [R] How to combine two rows (in a dataframe) into a > third row? > > Dear R-helpers, > > I have two rows in my dataframe: > > ID VALUE > 1A 10 > 1B 15 > > and I would like to combine these two rows into a single > (new) row in my > dataframe: > > ID VALUE > 1 25 > > ...simply by specifying a new value for ID and summing the two VALUES. > > I have been trying to do this with with rbind, but it's not working. > > I'd appreciate any pointers. > > Thanks, Mark Na > > [[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 confidential and may be subject to legal privilege. If you are not the intended recipient you must not use, disseminate, distribute or reproduce all or any part of this e-mail or attachments. If you have received this e-mail in error, please notify the sender and delete all material pertaining to this e-mail. Any opinion or views expressed in this e-mail are those of the individual sender and may not represent those of The New Zealand Institute for Plant and Food Research Limited. ______________________________________________ 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.
