Hello all and thanks in advance for any help or direction. I have co-authorship data that looks like:
Paper Author Year 1 SmithKK JonesSD 2008 2 WallaceAR DarwinCA 1999 3 HawkingS 2003 I would like: Paper Author Year 1 SmithKK 2008 1 JonesSD 2008 2 WallaceAR 1999 2 DarwinCA 1999 3 HawkingS 2003 Thanks for your patience with what is likely an easy question <r-help@r-project.org> [[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.