Re: [sage-devel] Re: Characteristic Classes - Implement Vector Bundles?
Hello, Having vector bundles would be nice! But what do you mean by *abstract* vector bundle? Ah. I meant vector bundles without specifying any maps. But since changes of frames/coordinates and continuations are convenient to have, this seems unavoidable. Where would you start if you'd program a vector bundle? As a general rule, it is indeed better to introduce things step by step, in a sequence of tickets, instead of a single big ticket. Then, it would be better to start with the tangent bundle, to introduce the algorithm and concepts first. Best regards, Michael --- Diese E-Mail wurde von Avast Antivirus-Software auf Viren geprüft. https://www.avast.com/antivirus -- 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.
[sage-devel] Re: CHomP
On Friday, May 3, 2019 at 10:22:25 AM UTC-7, Salvatore Stella wrote: > > Hi All, > has anyone tried installing CHomP recently? For me it fails applying > patches. > It is an old-style package and apparently it is very stale; does it > provide > any tangible speedup in `ChainComplex_class.homology` compared to the > default > pari algorithm? > Thanks > S. > > > It used to provide a speed up in computing the homology of simplicial complexes; if I remember right, it was also faster with homology of chain complexes. https://trac.sagemath.org/ticket/15202 is an old ticket for converting CHomP to a new-style package, but no one has worked on it in a few years. -- John -- 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.
[sage-devel] CHomP
Hi All, has anyone tried installing CHomP recently? For me it fails applying patches. It is an old-style package and apparently it is very stale; does it provide any tangible speedup in `ChainComplex_class.homology` compared to the default pari algorithm? Thanks S. -- 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.
Re: [sage-devel] No output from GAP
On Fri, May 3, 2019 at 5:10 PM E. Madison Bray wrote:
>
> On Fri, May 3, 2019 at 5:06 PM E. Madison Bray wrote:
> >
> > On Mon, Apr 29, 2019 at 2:30 AM Andrey Novoseltsev
> > wrote:
> > >
> > > Hello,
> > >
> > > I got a report about GAP problem in SageMathCell, but it looks like the
> > > GAP interface in Sage itself is having issues. I am getting an empty
> > > string from the following command:
> > > sage: print(gap.eval("""
> > > : D_4 := SmallGroup(8,3);
> > > : IsAbelian( D_4 );
> > > : List( ConjugacyClasses( D_4 ), Size );
> > > : IsCyclic( D_4 );
> > > : Size( AllSubgroups( D_4 ) );
> > > : Size( Set( D_4, Order ) );
> > > : IsSolvable( D_4 );"""))
> > >
> > > All commands work fine in GAP and even in Sage each one seems to be
> > > working, but certain combinations of them do not, while some do - I can't
> > > understand the system here...
> > >
> > > Does anyone have any ideas on what is going on?
> >
> > It might be a bug in the pexpect interface I guess. If I try, say,
> > just the first 2 or 3 snippets of the code you gave above I get the
> > full output. But by the `Size( AllSubgroups( D_4 ) );` it becomes
> > empty. I if I do just `D_4 := SmallGroup(8,3); Size( AllSubgroups(
> > D_4 ) );` it produces the correct output.
>
> Oh duh, I re-read the rest of the thread, and as Vincent pointed out,
> this is above the (seemingly arbitrary?) _eval_using_file_cutoff.
>
> I'm not sure why that's so buggy but I'm sure we can figure it out...
I see; it's because it writes the commands to a file, and then
executes the file in GAP by calling Read(...) on the filename, which
doesn't necessarily produce output for each command. This is just
like the difference in Python between entering several lines of code
one-by-one in the REPL, versus simply executing a script. You won't
see the result of each line unless it were wrapped in Print() or
something. Surely there is a better solution...
--
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.
Re: [sage-devel] No output from GAP
On Fri, May 3, 2019 at 5:06 PM E. Madison Bray wrote:
>
> On Mon, Apr 29, 2019 at 2:30 AM Andrey Novoseltsev wrote:
> >
> > Hello,
> >
> > I got a report about GAP problem in SageMathCell, but it looks like the GAP
> > interface in Sage itself is having issues. I am getting an empty string
> > from the following command:
> > sage: print(gap.eval("""
> > : D_4 := SmallGroup(8,3);
> > : IsAbelian( D_4 );
> > : List( ConjugacyClasses( D_4 ), Size );
> > : IsCyclic( D_4 );
> > : Size( AllSubgroups( D_4 ) );
> > : Size( Set( D_4, Order ) );
> > : IsSolvable( D_4 );"""))
> >
> > All commands work fine in GAP and even in Sage each one seems to be
> > working, but certain combinations of them do not, while some do - I can't
> > understand the system here...
> >
> > Does anyone have any ideas on what is going on?
>
> It might be a bug in the pexpect interface I guess. If I try, say,
> just the first 2 or 3 snippets of the code you gave above I get the
> full output. But by the `Size( AllSubgroups( D_4 ) );` it becomes
> empty. I if I do just `D_4 := SmallGroup(8,3); Size( AllSubgroups(
> D_4 ) );` it produces the correct output.
Oh duh, I re-read the rest of the thread, and as Vincent pointed out,
this is above the (seemingly arbitrary?) _eval_using_file_cutoff.
I'm not sure why that's so buggy but I'm sure we can figure it out...
--
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.
Re: [sage-devel] No output from GAP
On Mon, Apr 29, 2019 at 2:30 AM Andrey Novoseltsev wrote:
>
> Hello,
>
> I got a report about GAP problem in SageMathCell, but it looks like the GAP
> interface in Sage itself is having issues. I am getting an empty string from
> the following command:
> sage: print(gap.eval("""
> : D_4 := SmallGroup(8,3);
> : IsAbelian( D_4 );
> : List( ConjugacyClasses( D_4 ), Size );
> : IsCyclic( D_4 );
> : Size( AllSubgroups( D_4 ) );
> : Size( Set( D_4, Order ) );
> : IsSolvable( D_4 );"""))
>
> All commands work fine in GAP and even in Sage each one seems to be working,
> but certain combinations of them do not, while some do - I can't understand
> the system here...
>
> Does anyone have any ideas on what is going on?
It might be a bug in the pexpect interface I guess. If I try, say,
just the first 2 or 3 snippets of the code you gave above I get the
full output. But by the `Size( AllSubgroups( D_4 ) );` it becomes
empty. I if I do just `D_4 := SmallGroup(8,3); Size( AllSubgroups(
D_4 ) );` it produces the correct output.
--
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.
[sage-devel] Re: Characteristic Classes - Implement Vector Bundles?
Hi, Le jeudi 2 mai 2019 13:12:43 UTC+2, Michael Jung a écrit : > > Hey there, > for the next step of implementing characteristic classes, I'd like to > implement abstract vector bundles. > > 1) Do you agree? > Having vector bundles would be nice! But what do you mean by *abstract* vector bundle? 2) How would you proceed in doing so? It seems like it's not an easy task > at all (at least if you wish having all functionalities). > > I mean, for characteristic classes, you only need abstract local frames. > Maybe, I can start with that and leave other functionalities open for > later? And if yes, how can you manage that? > As a general rule, it is indeed better to introduce things step by step, in a sequence of tickets, instead of a single big ticket. Best wishes, Eric. -- 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.
