Michael test[!duplicated(paste(test$timestamp, test$user_id)),]
should remove the second (and subsequent) occurrences of duplicates. Your example suggests you don't always want to keep the first occurrence, but the rule which determines which occurrence you want to keep is not obvious to me. HTH .... Peter Alspach > -----Original Message----- > From: [EMAIL PROTECTED] > [mailto:[EMAIL PROTECTED] On Behalf Of Michael Pearmain > Sent: Wednesday, 24 September 2008 8:44 a.m. > To: r-help@r-project.org > Subject: [R] Contional > > Hi All, > > I'm having trouble selecting rows to delete, that i can't > seem to overcome. > > Below is some sample data, i am trying to dedup the data > based on each user, and simultaneously the timestamp (at the > side i have highlighted expected row to be removed) > > I've looked at the lag function but can't seem to make it work? > > My logic ran along the lines of an ifelse statement and then > remove after that, but it doesn't seem to work? Any help appreciated > > Let's call the data test > > test$lag <- ifelse(test$user_id==lag(test$user_id) > & test$timestamp==lag(test$timestamp),1,0) > > Can anyone help on this? > > Mike > > > > Source_type timestamp user_id > 75381 0 07-07-2008-21:03:55 848307909687 > 75379 1 07-07-2008-19:52:55 848307838407 > 75380 2 07-07-2008-19:54:14 848307838407 > 75378 1 07-07-2008-15:24:01 848285633277 > 75374 1 07-07-2008-13:39:17 848273633667 > 75377 2 07-07-2008-13:39:55 848273633667 > 75376 2 07-07-2008-13:39:55 848273633667 Remove > 75375 2 07-07-2008-13:56:05 848273633667 > 75373 1 07-07-2008-17:11:00 848272661427 > 75371 1 07-07-2008-13:19:00 848270431847 > 75372 2 07-07-2008-13:19:14 848270431847 > 75369 1 07-07-2008-12:49:16 848269676907 Remove > 75370 2 07-07-2008-12:49:16 848269676907 > 75366 1 07-07-2008-13:29:15 848263484847 > 75368 2 07-07-2008-13:29:44 848263484847 > > Thanks in advance > > [[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.
