Try table(): > adj <- table(d) # 'd' is your data.frame > adj group person a b c d Greg 1 0 0 0 Mary 0 1 0 1 Sam 1 1 1 0 Tom 0 1 1 1 If you have duplicate rows in the d then it will tally them up. You can can convert positives to 1's with adj[adj>0] <- 1.
Bill Dunlap Spotfire, TIBCO Software wdunlap tibco.com > -----Original Message----- > From: r-help-boun...@r-project.org [mailto:r-help-boun...@r-project.org] On > Behalf > Of Sebastian Haunss > Sent: Tuesday, February 05, 2013 1:07 AM > To: r-help@r-project.org > Subject: [R] adjacency list to non-symmetric matrix > > Dear R community, > > is there an easy way to convert an adjacency list (or a data-frame) to a > non-symmetric > matrix? > > The adjacency list has the following form: > > person group > 1 Sam a > 2 Sam b > 3 Sam c > 4 Greg a > 5 Tom b > 6 Tom c > 7 Tom d > 8 Mary b > 9 Mary d > > I need the data in a matrix with persons as rows and groups as columns: > > a b c d > Sam 1 1 1 0 > Greg 1 0 0 0 > Tom 0 1 1 1 > Mary 0 1 0 1 > > I know that there are several possibilities in some of the network packages > to convert > adjacency lists to symmetric or sparse matrices, but I couldn't find a way to > coerce them > into affiliation matrices. > > > kind regards > Sebastian > > -- > > PD Dr. Sebastian Haunss > SfB 597 - Transformations of the State > Universität Bremen > Linzer Str. 9a > 28359 Bremen > T: +49-(0)421-218-56654 > http://shaunss.ipgovernance.eu/ > > Recently published: > Haunss, Sebastian (2012), “Gewalt und Gewaltlosigkeit in sozialen Bewegungen”, > Forschungsjournal Soziale Bewegungen 25(4): 6–16. > Leifeld, Philip, and Sebastian Haunss (2012), “Political Discourse Networks > and the > Conflict over Software Patents in Europe”, European Journal of Political > Research 51(3): > 382–409. > > ______________________________________________ > 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. ______________________________________________ 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.