You are right, and you can see the reason like this:
sage: G = Gamma(5)
sage: G.ncusps??
shows that the code is a one-liner
return ZZ(len(self.cusps()))
i.e. a complete set of cusps is computed (to see how, do G.cusps??),
while for the other groups a formula is used, e.g.
sage: G = Gamma0(5)
On 19 dez, 21:43, Renan Birck Pinheiro renan.ee.u...@gmail.com
wrote:
Hi,
I'm using openSUSE 11.3 on x86_64. I try to install SAGE on it, and I
downloaded the Ubuntu tarball (the Fedora tarball gives the same errors).
[snip]
Recompiling sage was the solution.
Renan
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To post to this
Dear sage-support,
at #10496, David Roe gave me the advice to use PY_TYPE_CHECK rather
than isinstance in Cython files. I did so.
But actually I didn't know PY_TYPE_CHECK at all, and so I have a two
questions:
1) Apparently there are several PY_... functions. Where can I read
about them?
2)
On Mon, Dec 20, 2010 at 11:24 AM, Renan Birck Pinheiro
renan.ee.u...@gmail.com wrote:
On 19 dez, 21:43, Renan Birck Pinheiro renan.ee.u...@gmail.com
wrote:
Hi,
I'm using openSUSE 11.3 on x86_64. I try to install SAGE on it, and I
downloaded the Ubuntu tarball (the Fedora tarball gives the
On 12/20/10 1:42 PM, Simon King wrote:
Dear sage-support,
at #10496, David Roe gave me the advice to use PY_TYPE_CHECK rather
than isinstance in Cython files. I did so.
But actually I didn't know PY_TYPE_CHECK at all, and so I have a two
questions:
1) Apparently there are several PY_...
PY_TYPE_CHECK is just a wrapper macro around PyObject_TypeCheck which
dereferences and compares the object type fields. So that part should be
insanely fast.
sage: cython('cpdef t(x):\n for i in range(0,1000):\n
PY_TYPE_CHECK(x,int)'); timeit(t(5000), repeat=100)
625 loops, best of 100:
Aha, with Jason's answer:
Calling isinstance(x,int) on a python x is cheating, because Cython replaces
it with PyInt_Check (no inheritance to check!).
Calling isinstance on a C variable x goes through IS_INSTANCE which builds
an unnecessary python boolean.
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Em 20-12-2010 18:02, Pedro Sanchez escreveu:
That problem is caused due to a libreadline library mismatch between
those packaged with sage and those from the system.
I got 4.6 today, and same problem arose. Solution worked once more
again, delete sage's libreadline's thing.
Hmm. I would never
The PY_TYPE_CHECK macro exists primarily because Cython didn't used to
optimize isinstance.
On Mon, Dec 20, 2010 at 12:34 PM, Volker Braun vbraun.n...@gmail.com wrote:
PY_TYPE_CHECK is just a wrapper macro around PyObject_TypeCheck which
dereferences and compares the object type fields. So that
On Mon, Dec 20, 2010 at 12:27 PM, Jason Grout
jason-s...@creativetrax.com wrote:
On 12/20/10 1:42 PM, Simon King wrote:
Dear sage-support,
at #10496, David Roe gave me the advice to use PY_TYPE_CHECK rather
than isinstance in Cython files. I did so.
But actually I didn't know PY_TYPE_CHECK
Dear Volker, dear Jason,
thank you for your answers!
So, I chose the wrong example isinstance(x,int). With other types to
test, PY_TYPE_CHECK will be faster.
@Volker
But if you really write Cython code then you probably want to type the
argument so that the compiler knows what x is.
...
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 the ticketing procedure
to get this implemented?
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