[Nauty] Signal 40

igor igor.mat at uni-mb.si
Sun Jan 23 06:52:01 EST 2005


I'm using NAUTY to compute strong bounds on the chromatic number of
a vertex transitive graph.  The list of automorphisms of the graph
produced by NAUTY decreases the number of variables and computation
times drastically.  NAUTY works on my machie perfectly on graphs of
sizes up to almost 3000 (I've set MAXN in a C program based on 
nautyex.c to this value), and finds a lot of automorphisms.  However,
when instructed to return the automorphisms with the first vertex 
fixed (colored with the second color while all other vertices are
colored with the same color) NAUTY complains 

signal 40

on graphs with size 1024 (while 512 is still OK). The results seem
to be OK nevertheless.

Should I worry about this message?  Is there anything what could
improve performance?  (NAUTY is much much faster, and requires much
much less space then the rest of my code, so I don't mind, if it runs
say 100 times slower.)

Best regards,
                 igor

-- 
Igor Dukanovic
EPF Maribor
Slovenia/Europe






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