On Sat, Nov 22, 2008 at 10:25 PM, Tim Lahey <[EMAIL PROTECTED]> wrote:
>
>
> On Nov 23, 2008, at 1:01 AM, William Stein wrote:
>
>>
>> On Sat, Nov 22, 2008 at 9:34 PM, Tim Lahey <[EMAIL PROTECTED]>
>> wrote:
>>>
>>> As a fellow Maple user, I highly recommend that you look at the new
>>> symbolics in Sage, pynac. While support is still incomplete, it has
>>> capabilities more similar to Maple than the Maxima-based symbolics.
>>> It also tends to be much faster than the Maxima symbolics too.
>>>
>>
>> I'm glad you're excited by this, since I put a lot of work into it
>> (with Burcin) :-). Anyway, to try it out, just pass the ns=True option
>> to the var command. E.g.,
>>
>> sage: var('x,y',ns=True)
>> (x, y)
>> sage: expand((x+sin(y)*x)^3)
>> 3*sin(y)*x^3 + 3*sin(y)^2*x^3 + sin(y)^3*x^3 + x^3
>>
>> And this is a lot faster than the old ones:
>>
>> sage: time f = expand((x+sin(y)/sqrt(x))^500)
>> CPU times: user 0.04 s, sys: 0.01 s, total: 0.04 s
>> Wall time: 0.04 s
>>
>> sage: var('x,y',ns=False) # old symbolics
>> (x, y)
>> sage: time f = expand((x+sin(y)/sqrt(x))^500)
>> CPU times: user 0.58 s, sys: 0.12 s, total: 0.69 s
>> Wall time: 1.22 s
>>
>> Note that many things still are implemented with these symbolic
>> variables though -- it's
>> just that they are faster, and have a new design (e.g., pattern
>> matching rules).
>>
>
> I've been trying out them since you posted the pynac-0.1 spkg and
> refrained
> from upgrading until 3.2 since I couldn't get that package to work
> with the
> newer builds. I'm definitely excited about the possibility that I
> might be
> able to finally move over to Sage for regular use. Although, it's my
> understanding that integration is still using Maxima?
Ginac (on which Pynac is based) doesn't have any nontrivial symbolic
integration. So that's going to continue to depend on Maxima until
we:
* write our own
* switch to using sympy for integration (sympy does some integration)
* use code from giac, which does some integration
* Axiom?
I would definitely like to improve the ability of the integrate
command to use say Maple or Mathematica to optionally compute
integrals. Then people like you (in this thread) who do have Maple or
Mathematica laying around could still use it for that without having
to explicitly mess with the Sage Maple/Mathematica interfaces.
-- William
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