[R] adjacency list to non-symmetric matrix

[William Dunlap]

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-bounces at r-project.org [mailto:r-help-bounces at r-project.org] On Behalf
> Of Sebastian Haunss
> Sent: Tuesday, February 05, 2013 1:07 AM
> To: r-help at 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.
> 
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