PS the thesis is (un)available here: http://www.amazon.com/Integration-Algebraic-Functions-Lecture-Computer/dp/0387102906
On 23/12/2007, John Cremona <[EMAIL PROTECTED]> wrote: > It is possible that James Davenport, who spoke at Sage Days 6, might > wish to get in volced with a projtec to re-implement Risch's > algorithm. James's PhD was on this, around 1980, published in > Springer LNCS I seem to remember. He also worked on Scratchpad years > ago, when it developed by Jenks et al at IBM Yorktown Heights -- and > am I right in thinking that Axiom evolved from Scratchpad? > > James might have some useful advice even if he does not want to do any coding. > > When I started to implement what became mwrank I had useful advice > from James Davenport who was then the only person who had implemented > general 2-descent on elliptic curves. He had done it for the Antwerp > IV tables of elliptic curves, while still a high school student, in > some assembly language for a machine which no longer existed when I > asked him (around 1988), though he still had a magnetic tape with the > machine code on it... > > John > > On 23/12/2007, root <[EMAIL PROTECTED]> wrote: > > > > >Excellent. We were playing with the Risch algorithm in SymPy too. > > >If axiom could be installed in matter of minutes (last time I tried > > >it was 10 hours and it failed[1], in April), maybe it could be > > >considered as a base for a good integrator in Sage. But > > >currently it's imho much better to use Maxima's, because > > >Maxima is alreay in Sage and there are Python wrappers for it. And in the > > >long > > >term, it's imho better to rewrite the algorithm in Python, for > > >readibility. SymPy shows, that it is possible. > > > > Well if you're going to go to all of the trouble to re-implement Risch > > it would be worthwhile to spend the time to heavily document the > > algorithm. I'd suggest using some form of literate programming. It > > is a nontrivial exercise to re-implement. Axiom's integrator was > > written by the people who invented the algorithms. Unfortunately > > they did not document the details of how the code works. > > > > Tim > > > > > > > > > > > -- > John Cremona > -- John Cremona --~--~---------~--~----~------------~-------~--~----~ To post to this group, send email to sage-devel@googlegroups.com To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/sage-devel URLs: http://sage.scipy.org/sage/ and http://modular.math.washington.edu/sage/ -~----------~----~----~----~------~----~------~--~---
