[Nauty] new version of nauty available

Brendan McKay Brendan.McKay at anu.edu.au
Sun Oct 15 21:44:52 AEDT 2017


Release 2.6r10 of nauty&traces is available on the web site. The
changes are:

* Problems with input of graphs with 0 vertices were fixed with help
   from Kevin Ryde.  However, note that many utilities in the package
   will not work with such null graphs.  It is NOT TRUE that graphs of
   order 0 are now supported.  If you need them in your own code
   I suggest you treat them separately.

* The configuration script was improved with help from Kevin Ryde.

* Stronger measures are taken to ensure that the sort order used by
   shortg is plain byte order. This corresponds to the C collation
   order, also known as POSIX, but it may be different from the
   collation order used by default on your command line. This means
   that utilities like sort, uniq, comm and join might consider the
   output of shortg to be out of order. To avoid this, define the
   environment variable LC_ALL to equal the string "C".
      bash:   export LC_ALL=C
      tcsh:   setenv LC_ALL C
   If LC_ALL is undefined, it will also be sufficient to define
   LC_COLLATE to equal "C".  The POSIX standard says that LC_ALL
   takes precedence over LC_COLLATE if both are defined, but this
   might not be true for older systems.  If you really don't want
   to change environment variables, you can compile shortg with
   -DKEEP_SORT_LOCALE but beware that some collation orders are
   not even deterministic (i.e. different characters might compare equal).

Beta release 2.7b10 is also available.  In addition to the above,
the main routine nauty() now works for null graphs and some
utilities work for them too.  However, null graphs are not uniformly
supported through the package.  In addition, watercluster2 has
a new option Z for digraph6 output.  Recall that watercluster2 is
a program from Gunnar Brinkmann that is often much faster than
directg.

Brendan.



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