In ticket 10506, John Cremona wrote the following in reference to
Gamma(n): "Note that the next job is to add a method to return a set
of inequivalent cusps. The default implementation is stupidly slow (as
proved by the fact that the old default for ncusps() was to find all
the cusps and count them
I wrote the following function, which does the job. Function below
takes as input a positive integer N and outputs two objects: the first
output is a list [g_i] of hyperbolic elements in Gamma0(N) which
generate the abelianized (Gamma0(N)_hyp)_ab of the quotient
Gamma0(N)_hyp of Gamma0(N) by the su
On Sun, Dec 19, 2010 at 9:39 PM, John H Palmieri wrote:
> On Dec 19, 7:01 pm, Alex Raichev wrote:
>> Hi all:
>>
>> I get differently formatted answers using factor() multiple times on
>> the same polynomial. I wouldn't call it a bug, but it sure is
>> annoying when doctesting.
>>
>> Alex
>>
>> -
On Tue, Dec 21, 2010 at 10:29 AM, Jason Grout
wrote:
> On 12/21/10 11:36 AM, Robert Bradshaw wrote:
>>
>> On Tue, Dec 21, 2010 at 4:16 AM, Volker Braun
>> wrote:
No, it's because your loop is over 1 rather than 1000.
>>>
>>> Sharp eyes! :)
>>> So, to summarize, with the improved Cyt
On 12/21/10 11:36 AM, Robert Bradshaw wrote:
On Tue, Dec 21, 2010 at 4:16 AM, Volker Braun wrote:
No, it's because your loop is over 1 rather than 1000.
Sharp eyes! :)
So, to summarize, with the improved Cython one should always use isinstance
as it will be optimized to be at least as fas
Let m be a modular symbol for the congruence subgroup G=Gamma0(N) for
some N.
If one assumes m is cuspidal, there exist elements g in G such that m
is equivalent to the symbol {0,g(0)}.
How can I compute one such g with sage? If possible, I'd like to find
g with as small coefficients as possible.
On Tue, Dec 21, 2010 at 4:16 AM, Volker Braun wrote:
>> No, it's because your loop is over 1 rather than 1000.
>
> Sharp eyes! :)
> So, to summarize, with the improved Cython one should always use isinstance
> as it will be optimized to be at least as fast.
Yes, as long as the rhs is known by
Your product formula is a good idea. It's faster than my summation
formula.
On Dec 21, 3:40 am, John Cremona wrote:
> On Dec 21, 1:38 am, rje wrote:
>
> > Thanks for the helpful response. The appropriate code for computing
> > Gamma(n).ncusps() is
>
> > n=self.level()
> > if n<=2:
> >
> No, it's because your loop is over 1 rather than 1000.
Sharp eyes! :)
So, to summarize, with the improved Cython one should always use isinstance
as it will be optimized to be at least as fast. I guess we should remove the
PY_TYPE_CHECK macro from Sage altogether and replace every occurre
There's now a patch at #10506 (http://trac.sagemath.org/sage_trac/
ticket/10506) ready for review.
John Cremona
On Dec 21, 11:40 am, John Cremona wrote:
> On Dec 21, 1:38 am, rje wrote:
>
> > Thanks for the helpful response. The appropriate code for computing
> > Gamma(n).ncusps() is
>
> > n
On Dec 21, 1:38 am, rje wrote:
> Thanks for the helpful response. The appropriate code for computing
> Gamma(n).ncusps() is
>
> n=self.level()
> if n<=2:
> return[None,1,3][n]
> return ZZ(sum([moebius(d)*(n/d)^2/ZZ(2) for d in n.divisors()]))
>
> But can I impose on someone who knows t
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