[sage-devel] Re: calculus in SAGE/SymPy

2007-09-13 Thread Chris Chiasson
ack, first first paragraph has the sentences out of order - an example of giving a "useful result with an implicit assumption" is: http://reference.wolfram.com/mathematica/tutorial/IndefiniteIntegrals.html "Mathematica gives the standard result for this integral, implicitly assuming that n is not

[sage-devel] Re: gmp, mpfr, ecm

2007-09-13 Thread John Cremona
Thanks for the references -- it is very good that the gmp code is so well documented with references to the literature. It never ceases to amaze me how much improvement is possible on Euclid! John On 9/12/07, David Harvey <[EMAIL PROTECTED]> wrote: > > > On Sep 12, 2007, at 5:48 PM, John Cremon

[sage-devel] Re: QuotientRingElement

2007-09-13 Thread Martin Albrecht
> > RingElement > > -- QuotientRingElement_generic (*new*) > > -- -- MPolynomialQuotientRingElement (*new*) > > -- -- QuotientRingElement > > > > Thoughts? > > Looks good to me. Somehow I'm missing the point about why > this wouldn't just be the obvious right thing to do. Maybe you > could post

[sage-devel] Re: calculus in SAGE/SymPy

2007-09-13 Thread Robert Bradshaw
On Sep 12, 2007, at 9:52 PM, William Stein wrote: > Personally, I think you're applying some of the very structured > coercion > model thinking in this situation, which is I think the wrong approach > for symbol pushing and symbolic calculus. I think you're right... > Right now one gets the f

[sage-devel] Re: SAGE and inplace operators

2007-09-13 Thread Robert Bradshaw
An implementation is up to test and play with at http://www.sagemath.org:9002/sage_trac/ticket/624 On Sep 5, 2007, at 4:55 PM, Robert Bradshaw wrote: > On Sep 5, 2007, at 4:48 PM, David Harvey wrote: > >> On Sep 5, 2007, at 7:37 PM, Robert Bradshaw wrote: >> But I'm a bit concerned wh

[sage-devel] Re: calculus in SAGE/SymPy

2007-09-13 Thread Ondrej Certik
> "Mathematica gives the standard result for this integral, implicitly > assuming that n is not equal to -1." > Integrate[x^n, x] > > the result is x^(1+n)/(1+n) > > (this even happens when you give the option GenerateConditions->True) > > It would be much better to return the solution and its ass

[sage-devel] Re: Enumeration of totally real fields, continued

2007-09-13 Thread Bill Hart
Hi John, Despite having looked into the problem of computing gcd's efficiently, I don't know which algorithms are in practice faster for checking squarefreeness. In fact, to date, I am unable to tell you which algorithm is even asymptotically fastest for computing polynomial gcd. For integer gcd

[sage-devel] Re: SAGE and inplace operators

2007-09-13 Thread William Stein
On 9/13/07, Robert Bradshaw <[EMAIL PROTECTED]> wrote: > > An implementation is up to test and play with at > > http://www.sagemath.org:9002/sage_trac/ticket/624 > 1. Could you post some (impressive) benchmarks? 2. Could you post a little example session that specifically illustrates what's happ

[sage-devel] Re: QuotientRingElement

2007-09-13 Thread William Stein
On 9/13/07, Martin Albrecht <[EMAIL PROTECTED]> wrote: > > > > RingElement > > > -- QuotientRingElement_generic (*new*) > > > -- -- MPolynomialQuotientRingElement (*new*) > > > -- -- QuotientRingElement > > > > > > Thoughts? > > > > Looks good to me. Somehow I'm missing the point about why > > th

[sage-devel] Sage BugSquash Day 3

2007-09-13 Thread William Stein
Hi, Since nobody says they can't do Thursday, September 20th (one week from today), let's have *** SAGE BUG SQUASH DAY 3 http://wiki.sagemath.org/bug3 Thursday, September 20th

[sage-devel] Re: Sage BugSquash Day 3

2007-09-13 Thread David Harvey
On Sep 13, 2007, at 11:11 AM, William Stein wrote: > > Hi, > > Since nobody says they can't do Thursday, September 20th (one week > from today), let's have > > *** > SAGE BUG SQUASH DAY 3 > > http://wiki.sagemath.o

[sage-devel] SAGE-2.8.4.2 release candidate 1

2007-09-13 Thread William Stein
Hi, I've posted the release candidate for sage-2.8.4.2 here: http://sage.math.washington.edu/tmp/sage-2.8.4.2.rc1.tar If it builds for people, etc., I will release sage-2.8.4.2 later today. -- William Stein Associate Professor of Mathematics University of Washington http://wstein.org --~-

[sage-devel] Re: Enumeration of totally real fields, continued

2007-09-13 Thread Bill Hart
OK, I've looked into this more carefully and the reason why I don't know which is the best algorithm for polynomial gcd over Z is that most people when writing papers don't consider this case carefully when they come to do asymptotic or runtime analysis. That is presumably because it is hard to do

[sage-devel] Re: SAGE and inplace operators

2007-09-13 Thread Robert Bradshaw
On Sep 13, 2007, at 7:11 AM, William Stein wrote: > On 9/13/07, Robert Bradshaw <[EMAIL PROTECTED]> wrote: >> >> An implementation is up to test and play with at >> >> http://www.sagemath.org:9002/sage_trac/ticket/624 >> > > 1. Could you post some (impressive) benchmarks? I've put some up on tra

[sage-devel] Re: Enumeration of totally real fields, continued

2007-09-13 Thread Bill Hart
Having said all that, Magma uses the GCDHEU algorithm and a modular algorithm. Note that m in the above is the size in bits of the coefficients of the resultant, which you don't know an a priori bound for. You can figure out a bound however, but as in both algorithms, you need to know the roots of

[sage-devel] sage-2.8.4.2 released!

2007-09-13 Thread William Stein
Hi, I have released sage-2.4.8.2, which is a minor incremental release, mainly "just because" releasing early and often is vastly easier than releasing late and rarely: SAGE-2.8.4.2 closes the following trac tickets: 262 Alex Ghitza: extend point counting on elliptic curves to non

[sage-devel] Re: Enumeration of totally real fields, continued

2007-09-13 Thread John Voight
Hi Bill, Thanks for your messages--it certainly is an interesting problem when viewed in context. For me, my polynomials are tiny: small degree (<=11) and very small coefficients. Moreover, I already have computed the roots to some numerical precision and only call this when there appears to be

[sage-devel] Re: Enumeration of totally real fields, continued

2007-09-13 Thread John Voight
Hi Will, > > (2) I have my Cython code in a tr_data.spyx file and my Python code in > > a totallyreal.py file. How do I include the former into the latter-- > > or do I have to include both at the prompt? > > You can't trivially get at tr_data.spyx from totallyreal.py, but you can > from a .sage

[sage-devel] Re: Enumeration of totally real fields, continued

2007-09-13 Thread Bill Hart
Hi John, Yes those are tiny polynomials. The way NTL works is to compute the content of both polynomials and divide out by that, compute the gcd of the contents, break up one prime at a time and compute the gcd mod p. After each recombination (it's all done "in place") it checks to see if the gcd

[sage-devel] Re: Enumeration of totally real fields, continued

2007-09-13 Thread Bill Hart
It takes Pari 2s to do a test of 10^5 polynomials of the form you give, for irreducibility. It also takes it 2s to check if 10^5 pairs give you isomorphic number fields. It takes 3s to compute all the discriminants using nfdisc. If it is taking 57s it's off its head. Coercion should be just about

[sage-devel] Re: Enumeration of totally real fields, continued

2007-09-13 Thread William Stein
On 9/13/07, John Voight <[EMAIL PROTECTED]> wrote: > > Hi Will, > > > > (2) I have my Cython code in a tr_data.spyx file and my Python code in > > > a totallyreal.py file. How do I include the former into the latter-- > > > or do I have to include both at the prompt? > > > > You can't trivially g