I'm not sure what is happening here, but apparently the problem is resolved if we start the PageRank calculation from a completely uniform initial vector instead of the in-degree vector plus some random noise. The problem is that it breaks some of our PageRank test cases where the in-degree vector plus some random noise seemed to work better.
T> On 19 Mar 2013, at 15:28, Tamás Nepusz <[email protected]> wrote: > Hi, > > You are right, the PageRank values should all be between 0 and 1. Your graph > seems to be a corner case for which the ARPACK solver fail to converge, > although I have no idea why. I will evaluate and get back to you. > > -- > T. > > On 19 Mar 2013, at 01:22, Krishna Sandeep Reddy Dubba <[email protected]> > wrote: > >> Hi all, >> I am trying to compute pagerank for a graph and I am getting strange values >> for pagerank. to my knowledge, the page rank values should be between 0 and >> 1 but i get very large or very small number (> 1 and < 0). I attach the .gml >> file and here is the output. Please let me know what I am doing wrong or is >> this graph some strange special case? >> >> In [4]: import igraph >> In [5]: g = igraph.read(f) >> In [6]: pr = g.pagerank() >> In [7]: pr >> Out[7]: >> [1323658113126271.8, >> -264731622625256.4, >> -264731622625256.44, >> -264731622625256.44, >> 264731622625252.84, >> -264731622625256.4, >> 264731622625252.94, >> -264731622625256.44, >> -264731622625254.56, >> 264731622625252.78, >> -1588389735751520.0, >> 4500437584629358.5, >> -264731622625254.47, >> -264731622625254.53, >> -264731622625254.5, >> 264731622625252.8, >> -264731622625256.4, >> -264731622625256.47, >> -529463245250509.7, >> 264731622625253.78, >> -264731622625256.34, >> -264731622625256.34, >> -264731622625256.4, >> -264731622625256.44, >> -264731622625256.47, >> -264731622625256.4, >> -264731622625256.44, >> -264731622625256.44] >> >> Thanks, >> dksr >> <A0043022_50052754.gml>_______________________________________________ >> igraph-help mailing list >> [email protected] >> https://lists.nongnu.org/mailman/listinfo/igraph-help > _______________________________________________ igraph-help mailing list [email protected] https://lists.nongnu.org/mailman/listinfo/igraph-help
