On Thu, 21 Mar 2019 at 18:42, Ai Bo <boaisp...@gmail.com> wrote: > I found it. Thank you. > I also tried the command listed above. > I am confused. Where is this "I]~~~~~~w"? > Is it a file? How did Graph load this? > > In my program, my code looks like this: > i=12 > for G in graphs.nauty_geng(str(i) + " -C"): > q = True > for j in range (0,i): > S = Sandpile(G,j) > if S.identity() != S.max_stable(): > q = False > break > > > > If I use geng to generate graphs, how should I load them in my for loop so > I can check with Sandpile? >
I think the bottleneck in you computation is not geng, but Sandpile: you spend much more time computing Sandpile compared with asking geng for the next graph. > On Thursday, March 21, 2019 at 8:46:56 AM UTC-7, Dima Pasechnik wrote: >> >> On Thu, Mar 21, 2019 at 3:03 PM Ai Bo <boai...@gmail.com> wrote: >> >> > is this "nauty26r7/geng" a program available? >> >> geng is installed in local/bin/ sub-directory of your Sage >> installation, as a part of Sage's standard package nauty. >> >> > Also, as Python is slow, any part of the nautygen can be written in >> other language, such as C/C++? >> >> it is written in C, so it's quite fast in this sense. >> >> > >> > Thanks, >> > Laura >> > >> > On Wednesday, March 20, 2019 at 11:48:38 PM UTC-7, Jori Mäntysalo (TAU) >> wrote: >> >> >> >> On Thu, 21 Mar 2019, Ai Bo wrote: >> >> >> >> > Is there a way to "random access"? For example, access the nth >> element >> >> > in the "generator", instead of one by one? >> >> >> >> Kind of. As a most time is propably spent by creating Python data >> >> structures for SageMath, you can use nautygen directly to generate >> huge >> >> number of graphs. >> >> >> >> As an example, it takes below 5 seconds to generate all biconnected >> graphs >> >> on 10 vertices, and I took third last one: >> >> >> >> $ nauty26r7/geng 10 -C | tail -3 | head -1 >> >> >A /home/jm58660/lat-koe/nauty26r7/geng -Cd2D9 n=10 e=10-45 >> >> >Z 9743542 graphs generated in 4.59 sec >> >> I]~~~~~~w >> >> >> >> and now >> >> >> >> sage: g = Graph('I]~~~~~~w', format='graph6') >> >> sage: g.is_biconnected() >> >> True >> >> >> >> >> >> -- >> >> Jori Mäntysalo >> >> >> >> Tampereen yliopisto - Ihminen ratkaisee >> > >> > -- >> > You received this message because you are subscribed to the Google >> Groups "sage-devel" group. >> > > To unsubscribe from this group and stop receiving emails from it, send >> an email to sage-devel+...@googlegroups.com. >> > To post to this group, send email to sage-...@googlegroups.com. >> > > Visit this group at https://groups.google.com/group/sage-devel. >> > For more options, visit https://groups.google.com/d/optout. >> > -- > You received this message because you are subscribed to the Google Groups > "sage-devel" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to sage-devel+unsubscr...@googlegroups.com. > To post to this group, send email to sage-devel@googlegroups.com. > Visit this group at https://groups.google.com/group/sage-devel. > For more options, visit https://groups.google.com/d/optout. > -- You received this message because you are subscribed to the Google Groups "sage-devel" group. To unsubscribe from this group and stop receiving emails from it, send an email to sage-devel+unsubscr...@googlegroups.com. To post to this group, send email to sage-devel@googlegroups.com. Visit this group at https://groups.google.com/group/sage-devel. For more options, visit https://groups.google.com/d/optout.