[Nauty-list] geng for large sizes
Brendan McKay
bdm at cs.anu.edu.au
Wed Sep 19 15:59:55 EST 2007
Thanks to Keith and Gordon for finding a problem in geng. Actually
it is fixed already in nauty version 2.4 even though I have no
recollection of fixing it.
The problem is that no graphs were produced for n > 28 when
none of -b,-t,-f,-m were given.
The simplest workaround is to add -m. The best workaround is
to either patch geng.c and recompile, or to get version 2.4
from the web page. I already applied the patch to version 2.2
as provided on the web page.
The required patch: Change
if (maxn + 4 > 8*sizeof(xword)) savemem = TRUE;
to
if (maxn + 4 > 8*sizeof(xword)) savemem = sparse = TRUE;
--------
Meanwhile, I put Beta 6 of version 2.4 on the web page.
It has no known bugs (so find some for me). The latest set of
changes, from the tail of the file README is:
July 12, 2007: Added -f option to directg.
Aug 14, 2007: Added -i,-I,-K options to shortg, parallel to labelg.
Since -k is used in labelg in place of -I, changed labelg
to use -I also, with -k remaining as an undocumented
compatibility feature.
Aug-Sep 2007: Minor things:
* naututil-h.in now defines CPUTIME=0.0 as a last resort
* gtools.c now implements EDGECODE (not used anywhere yet)
* fixed definition of SG_FREE in nausparse.h (not used)
* geng favours space over time for n > 28
Brendan.
Nauty page: http://cs.anu.edu.au/~bdm/nauty/
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