[sage-combinat-devel] Re: [sage-devel] Re: a problem in the new permutation groups code (and a solution ?)
Say, you have 1, 2, (1,2), (2,(1,2)), and perhaps other stuff in the domain. How many different meanings does the orbit of ((2,(1,2)),((2,(1,2))) have? How can you guess the right action for it? Dima it's getting boring. Let's say that I do not try to guess anything if that's a problem, do we agree that a function named orbit which knows the type of its input from the value of action wiill never encounter a ambiguous input nor return an ambiguous output ? Nathann -- You received this message because you are subscribed to the Google Groups sage-combinat-devel group. To unsubscribe from this group and stop receiving emails from it, send an email to sage-combinat-devel+unsubscr...@googlegroups.com. To post to this group, send email to sage-combinat-devel@googlegroups.com. Visit this group at http://groups.google.com/group/sage-combinat-devel?hl=en. For more options, visit https://groups.google.com/groups/opt_out.
[sage-combinat-devel] Re: [sage-devel] Re: a problem in the new permutation groups code (and a solution ?)
Helloo !!!
I think its unambiguous to define the orbit of x recursively as
1. use the action on domain elements if x is a domain element
2. otherwise, assume that the x is a list/set/... of domain elements
Well. It is when you know what you are doing and work on a spcific group.
When you write a Sage method, though, it is embarassing if you do not know
wheter the orbit of a pair of elements is a set of element (input
considered as element) or a set of pairs of elements (input considered as a
se of elements).
Really there is no problem with this patch except that Dima does not like
that the elements of a group could be things like 1,2,{1,2}, which makes
{1,2} ambiguous (element? set of two elements?) ... What we did before is
guess the type of INPUT according to a keyword named action (that we need
anyway, if only to differentiate between OnTuples and OnSets) and
everything works fine
Nathann
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[sage-combinat-devel] Re: [sage-devel] Re: a problem in the new permutation groups code (and a solution ?)
And PLEASE if you answer this thread please also send your answer to sage-devel, not only sage-combinat. Nathann -- You received this message because you are subscribed to the Google Groups sage-combinat-devel group. To unsubscribe from this group and stop receiving emails from it, send an email to sage-combinat-devel+unsubscr...@googlegroups.com. To post to this group, send email to sage-combinat-devel@googlegroups.com. Visit this group at http://groups.google.com/group/sage-combinat-devel?hl=en. For more options, visit https://groups.google.com/groups/opt_out.
[sage-combinat-devel] Re: [sage-devel] Re: a problem in the new permutation groups code (and a solution ?)
On Friday, March 22, 2013 2:51:05 PM UTC+1, Nathann Cohen wrote: I think its unambiguous to define the orbit of x recursively as 1. use the action on domain elements if x is a domain element 2. otherwise, assume that the x is a list/set/... of domain elements Well. It is when you know what you are doing and work on a spcific group. For non-interactive you either perform argument validation yourself or use the optional parameter G.orbit(foo, action='OnTuples'). -- You received this message because you are subscribed to the Google Groups sage-combinat-devel group. To unsubscribe from this group and stop receiving emails from it, send an email to sage-combinat-devel+unsubscr...@googlegroups.com. To post to this group, send email to sage-combinat-devel@googlegroups.com. Visit this group at http://groups.google.com/group/sage-combinat-devel?hl=en. For more options, visit https://groups.google.com/groups/opt_out.
Re: [sage-combinat-devel] Re: [sage-devel] Re: a problem in the new permutation groups code (and a solution ?)
For non-interactive you either perform argument validation yourself or use the optional parameter G.orbit(foo, action='OnTuples'). Oh. Ok, this is fine ! So Dima, do we guess the value of action when it is set to None, then translate the output according to the value of action ? That's a good answer ! Nathann -- You received this message because you are subscribed to the Google Groups sage-combinat-devel group. To unsubscribe from this group and stop receiving emails from it, send an email to sage-combinat-devel+unsubscr...@googlegroups.com. To post to this group, send email to sage-combinat-devel@googlegroups.com. Visit this group at http://groups.google.com/group/sage-combinat-devel?hl=en. For more options, visit https://groups.google.com/groups/opt_out.
[sage-combinat-devel] Re: [sage-devel] Re: a problem in the new permutation groups code (and a solution ?)
On 2013-03-22, Nathann Cohen nathann.co...@gmail.com wrote:
--bcaec5430e1288051e04d883f5b8
Content-Type: text/plain; charset=ISO-8859-1
For non-interactive you either perform argument validation yourself or use
the optional parameter G.orbit(foo, action='OnTuples').
Oh. Ok, this is fine !
So Dima, do we guess the value of action when it is set to None, then
translate the output according to the value of action ? That's a good
answer !
We need to fix the domain design first, and here is why (I already wrote
this on the ticket, so I repeat myself):
Take, say, directed 3-cycle, and label its vertices, in the cyclic
order, 1, 2, (1,2). So you get G=Z_3, the automorphism group of this
digraph, acting on the domain V=(1,2,(1,2)). Next, ask for the orbit of
the arc (1,2) of the digraph under G. OK, fine, it is
A=((1,2),(2,(1,2)),((1,2),1). Now, note that the intersection of V and A
equals {(1,2)}. The intersection of two distinct orbits of a group is
not empty...
Would Evariste Galois raise from his grave and chase the designer
of this?
:-)
Dima
Nathann
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Re: [sage-combinat-devel] Re: [sage-devel] Re: a problem in the new permutation groups code (and a solution ?)
Would Evariste Galois raise from his grave and chase the designer of this? I answered on the ticket, and said that I would help him if he did. But Dima you know that this thing will take ime if somebody actually ends up doing it and it's not related to this ticket. Why do you want to block it over that ? Nathann -- You received this message because you are subscribed to the Google Groups sage-combinat-devel group. To unsubscribe from this group and stop receiving emails from it, send an email to sage-combinat-devel+unsubscr...@googlegroups.com. To post to this group, send email to sage-combinat-devel@googlegroups.com. Visit this group at http://groups.google.com/group/sage-combinat-devel?hl=en. For more options, visit https://groups.google.com/groups/opt_out.
[sage-combinat-devel] Re: [sage-devel] Re: a problem in the new permutation groups code (and a solution ?)
On 2013-03-22, Nathann Cohen nathann.co...@gmail.com wrote: --f46d040f9ba4da0f5504d8848510 Content-Type: text/plain; charset=ISO-8859-1 Would Evariste Galois raise from his grave and chase the designer of this? I answered on the ticket, and said that I would help him if he did. But Dima you know that this thing will take ime if somebody actually ends up doing it and it's not related to this ticket. Why do you want to block it over that ? as I explained, the code you don't like there (cause it does not work on insane inputs) would work fine on sane inputs. And the uglier code you prefer would break things on insane inputs, too, although at some other point, e.g. at the one I outlined above in this thread. Dima Nathann -- You received this message because you are subscribed to the Google Groups sage-combinat-devel group. To unsubscribe from this group and stop receiving emails from it, send an email to sage-combinat-devel+unsubscr...@googlegroups.com. To post to this group, send email to sage-combinat-devel@googlegroups.com. Visit this group at http://groups.google.com/group/sage-combinat-devel?hl=en. For more options, visit https://groups.google.com/groups/opt_out.
Re: [sage-combinat-devel] Re: [sage-devel] Re: a problem in the new permutation groups code (and a solution ?)
as I explained, the code you don't like there (cause it does not work on insane inputs) would work fine on sane inputs. And the uglier code you prefer would break things on insane inputs, too, although at some other point, e.g. at the one I outlined above in this thread. It does not break things on insane input -- let's decide where we discuss this, I just answered that on the ticket -- for you are (from Sage's point of view) perfectly aware of what you are doing when you intersect : - The orbit of a vertex which you obtained by doing g.action( x, action = OnPoints ) - The orbit of an edge which you obtained by doing g.action( (x,y), action = OnSets) Hence you KNOW that you are intersecting things of different types. We might as well say that the output of g.action( x, action = OnPoints ) is of type OrbitOfPoint and g.action( (x,y), action = OnSets) of type OrbitOfSet. You actually know this information because you filled the action argument yourself. You can infer the type of what is being returned just from the value of action. Nathann -- You received this message because you are subscribed to the Google Groups sage-combinat-devel group. To unsubscribe from this group and stop receiving emails from it, send an email to sage-combinat-devel+unsubscr...@googlegroups.com. To post to this group, send email to sage-combinat-devel@googlegroups.com. Visit this group at http://groups.google.com/group/sage-combinat-devel?hl=en. For more options, visit https://groups.google.com/groups/opt_out.
