On 2014-09-11, 'Martin R' via sage-devel <sage-devel@googlegroups.com> wrote:
> Am Donnerstag, 11. September 2014 01:36:40 UTC+2 schrieb Nils Bruin:
>>
>> On Wednesday, September 10, 2014 10:54:06 AM UTC-7, Nils Bruin wrote:
>>>
>>> On Wednesday, September 10, 2014 10:38:50 AM UTC-7, Nils Bruin wrote:
>>>>
>>>> sage: Permutation([0,1,2])
>>>>
>>>
>> In fact, one CAN see from this list whether the permutation is 0-based or
>> 1-based, since every element from the domain must must occur exactly once,
>> so
>>
>> Permutation([1,2,0]) is a cyclic permutation on the 3 element set {0,1,2}
>> and Permutation([2,3,1]) is a cyclic permutation on {1,2,3}. So, in cycle
>> notation, 0- or 1-based doesn't matter (unless you're explicit about
>> domain, but then you should just be explicit about domain) and with
>> enumerated-images notation you can distinguish the two. I guess the only
>> point then is whether it's acceptable to have
>>
>> sage: Permutation([2,3,1])
>> [0,2,3,1]
>>
>> (but really, we could just always suppress the printing of fixed initial
>> and tail, in which case the printing problem goes away too).
>>
>
> Indeed. The only thing which I really really find annoying is the special
> notation for circular permutations.
Well, there are two ways to make this consistent:
1) it being deprecated and removed, eventually.
i.e. things like Permutation((3,5,7))
must become Permutation(['(3,5,7)'])
2) things like Permutation((3,5,7),(1,2),(42,41))
should be allowed as well.
I'd much prefer 2). Should we hold a formal vote?
Dima
--
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 http://groups.google.com/group/sage-devel.
For more options, visit https://groups.google.com/d/optout.
