On Sat, 29 Sep 2018, 10:32 Simon King, <[email protected]> wrote:
> Hi Dima, > > On 2018-09-29, Dima Pasechnik <[email protected]> wrote: > > On Sat, Sep 29, 2018 at 9:58 AM Simon King <[email protected]> > wrote: > >> > >> On 2018-09-29, Simon King <[email protected]> wrote: > >> > Too bad: When the error occurs and I adjust the pool size then > >> > afterwards the previously defined objects in gap are gone. > >> > >> Additional problem: Even when I increase the memory limit sufficiently, > >> gap-via-pexpect takes substantially longer than libgap to compute the > >> double cosets. Why is that? There shouldn't be big traffic in the > >> interface whan just doing DC = G.DoubleCosetRepsAndSizes(N,N). > > > > Just use libGAP, perhaps? > > (and do the port of the corresponding functionality to libGAP, if you > have time) > > Rewriting my whole p_group_cohomology package to libGAP would be work > that I'd rather avoid. > I believe making libGAP the default GAP interface is the way to go, and much of the work needed for this conversion is already done... > Given a group defined in gap-via-pexpect, how to put it into libGAP? > Slight complication: My groups come with a name. Hence, the string > representation of the group is not good, libGAP doesn't understand it: > > sage: G = gap.SymmetricGroup(6) > sage: G.SetName('"G"') > sage: libgap.eval(G) > ... > ValueError: libGAP: Error, Variable: 'G' must have a value > libgap's GAP objects are just thin cython wrappers around GAP's objects in memory. So you basically need to send to libgap a complete valid GAP statement defining G. > So, how can I make gap produce data that allow to reconstruct the group? > Is libgap.Group(G.GeneratorsOfGroup()) the way to go? For permutation > groups probably it is. But for polycyclic groups, as provided by the > SmallGroups library? > sage: G = gap.SmallGroup(720,761) > sage: G > Group( [ f1, f2, f3, f4, f5, f6, f7 ] ) > sage: libgap.Group(G.GeneratorsOfGroup()) > ... > ValueError: libGAP: Error, Variable: 'f1' must have a value > > Concerning your hint to use the ACE package: After installing > gap_packages, DC = G.DoubleCosetRepsAndSizes(N,N) takes a very long > time in gap-via-pexpect (much longer than with libGAP), but so far it > didn't crash. But it is VERY long. So, rewriting everything to > libGAP might be the way to go after all. Sigh. Will be tedious work... > > Worse: It seems to me that after installing gap_packages, libgap takes > long as well. > ACE is not in gap_packages AFAIK. > Best regards, > Simon > > -- > You received this message because you are subscribed to the Google Groups > "sage-support" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected]. > To post to this group, send email to [email protected]. > Visit this group at https://groups.google.com/group/sage-support. > For more options, visit https://groups.google.com/d/optout. > -- You received this message because you are subscribed to the Google Groups "sage-support" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To post to this group, send email to [email protected]. Visit this group at https://groups.google.com/group/sage-support. For more options, visit https://groups.google.com/d/optout.
