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interpreting cosparallel output

2015-09-13
2015-09-14
  • Brooks Ambrose

    Brooks Ambrose - 2015-09-13

    Hello,

    I'm very interested in using cosparallel for my research, and first thank
    you very much for inventing this great tool. I don't see an active
    discussion or issue tracker for the software so please point me in the
    right direction if there is a better venue for this question. I have
    attached a sample of output for my graph generated by a command like:

    $ ./cos -P 1 input.mcliques

    This was a test using one thread. I don't know if I understand the output
    and I have not found the answer in the documentation. I hope you can tell
    me if this is sensible output, a bug, or if there is additional
    post-processing that is required or recommended. I've attached a sample of
    output for k=9 communities, as well as the console output. My questions are:

    • Why are there multiple lines corresponding to the same community id?
      The User Guide says about the <community_id>, "This integer uniquely
      identifies the community".
    • Lines with the same <community_id> often contain the same
      <maximal_clique> ids. Should these lines be combined and the set of unique
      <maximal_clique> ids be treated as the k-clique community?
    • Are these redundant lines/ids actually correct or do they indicate an
      error?

    Thank you in advance,
    Brooks Ambrose

    Brooks Ambrose, M.A., C.Phil.
    Instructor, Berkeley School of Information
    University of California, Los Angeles
    brooksambrose@berkeley.edu

     
  • Simone Mainardi

    Simone Mainardi - 2015-09-14

    Brooks,

    Thanks for reaching out.

    Each community file (e.g., 9_communities.txt) has multiple lines corresponding to the same community id since each line correspond to a unique maximal clique. By construction, each k-clique community is made up of overplapping maximal cliques but is defined on edges -- and not on nodes. In other words, if you have a k-clique community C spanning a set of nodes N in a graph G, this does not equal the subgraph of G with the nodes in N. For this reason, the software COS outputs the full list of maximal cliques for each community, one per line.

    So for the sake of example, if we consider an excerpt of the file 9_communities.txt:

    [...]
    0:1042 1587 1590 1594 1598 1607 1613 2134 2136 2299
    0:1042 1590 1593 1594 1598 1607 1613 2136 2283 2299
    0:1590 1593 1594 1598 1607 1613 1619 2136 2283 2299
    [...]

    we have that 9-clique community identified by 0 has three overlapping maximal cliques with size 10, among others.

    Maximal cliques, expressed al lists of their memers, are indicated on the right of the semi-colon, See for example the overlapping node 2136 in bold above.

    To sum up, there are no redundant lines or errors. Everything looks OK.

    Simone

    ps. I enclose here your files for completeness.

     

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