Hi Dima,
On 2018-12-26, Dima Pasechnik <dimp...@gmail.com> wrote:
>> 1. Creating examples in the doc strings. Reason: I simply don't know
>> how to express the GAP command
>> Group( [ (1,2)(3,8)(4,6)(5,7), (1,3)(2,5)(4,7)(6,8) ] )
>> in libgap. I tried
>> libgap.Group( [ ((1,2),(3,8),(4,6),(5,7)), ((1,3),(2,5),(4,7),(6,8)) ] )
>> but it fails.
>
> What are these permutations, type-wise? Are they Sage permutations, or
> just strings?
> The following works:
>
> sage: G=PermutationGroup( [ ((1,2),(3,8),(4,6),(5,7)),
> ((1,3),(2,5),(4,7),(6,8)) ] )
> sage: libgap(G)
> Group([ (1,2)(3,8)(4,6)(5,7), (1,3)(2,5)(4,7)(6,8) ])
Seems awkward to me. I expected that libgap.Group([((1,2),...]) would
work with the same input that works for PermutationGroup. See #26960.
> Isn't it there already?
>
> sage: libgap.set_global('bla',[1,2])
> sage: libgap.get_global('bla')
> [ 1, 2 ]
Is that a convenience method? So far, I was directly using
DeclareGlobalVariable and InstallValue directly.
So, I will start using it. Thanks for the pointer!
> With IO package (which already seems to work with new libgap, just needs
> a bit of extra work, hopefully done this week, see
> https://trac.sagemath.org/ticket/26930)
> https://www.gap-system.org/Manuals/pkg/io-4.5.4/doc/chap5.html#X81BBA46880EBFC7D
>
> (I never used it myself, so YMMV)
A few years ago I tried to understand the IO package, but at that time
couldn't get it to work at all. In addition, it would require a package
in GAP, in addition to database_gap that the cohomology package relies
on.
But is it is something that could be part of gap_packages, and if the
GAP documentation is clear enough (that's very often not the case, I
often need to do experiments before understanding what is written in the
GAP docs), it may be an option for *new* pickles. But it won't be useful
for loading old pickles.
Best regards,
Simon
--
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.
