On Sun, Nov 2, 2008 at 11:46 AM, mabshoff <mabsh...@googlemail.com> wrote:And I think we still want to have as many conversions between
> On Nov 2, 11:38 am, "William Stein" <wst...@gmail.com> wrote:
>> <h...@finanz.math.tugraz.at> wrote:
>> > Hi,
>> > I have written some code for the Maxima interface.
>> > calculus1.patch implements the conversion from Maxima
> This should come in handy, but starting with 3.2 we will finally have
Maxima and Sage as possible, even if Maxima isn't the default
backend for symbolic manipulation. It's still very good for
Maxima and Sage to be able to communicate. The more
capabilities for communication between Sage and other systems,
>> > calculus2.patch adds symbolic gamma and factorial functions.
> Provided the factorial bit does not interfere with the current non-
I didn't look at the patch, but just want to comment that using
>> > Finally calculus3.patch renames the symbolic factorial to factorial(),
> I don't like this patch at all since it forces us to use a Maxima
sage.calculus.calculus.factorial instead of sage.rings.arith.factorial
doesn't a priori imply that Maxima is used to compute factorials.
I.e., I could imagine an implementation where GMP is still used
sage: time n = factorial(10^6)
> When the point counting code was using Maxima to computeDo you really mean "three orders of magnitude", i.e., a factor of 1000? :-)
> ceil, floor and sqrt the code as a whole was slower by a factor of
> three which illustrates nicely why we don't want to use Maxima unless
> there is a good reason to do so. Especially considering that usingIf a ticket is posted with the third patch, the reviewer should just make
> mpfr's functions was abotu a million times faster since there is no
> pexpect overhead. I could see using that code in case the argument is
> non-integer, but not using the highly optimized gmp implementation for
> something that is many orders of magnitude slower is just not what we
> want to do.
sure that factorial(n) for input an integer (1) doesn't slow down, and (2)
returns an integer.
>> > The patches are against 3.2-alpha1, after applying all 3 patches
>> > Here is a sample session with the new functionality:
>> > sage: var('x,y')
>> > [ 1 x x^2]
>> > [[ 1 x x^2]
>> > [Full MatrixSpace of 3 by 3 dense matrices over Symbolic Ring,
>> > sage: gamma(x/2)(x=5)
>> > sage: f = factorial(x + factorial(y))
>> > sage: f(y=x)(x=3)
>> > I hope it is useful.
>> > Greetings,
>> Thanks! Could you write to Michael Abshoff (<mabsh...@googlemail.com>) and ask
Associate Professor of Mathematics
University of Washington
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