Dear Michael, I am glad that you have made some progress.
I am copying this to sage-devel since the questions you ask are about how to use Sage and not about this particular problem (which is to compute integral points on elliptic curves, if anyone on sage-devel is reading this). 2008/6/4 Michael Mardaus <[EMAIL PROTECTED]>: > Dear John Cremona, > > the last weeks we were working on the integral point computation over Q. > After some basic problems of how to code in sage we decided to write a > python file which uses sage via > >from sage.all import * > It seems like it is not the best solution because while testing the code > we get a numerical overflow from python (at approx. 1e308 which isn't a > problem in sage) > How can we solve this problem? Can we force sage to run the .py file > without python? (We also have to use ** instead of ^) Why don't you give your file a .sage extension and load it from Sage? Upi still have access to all of Python. I cannot think of a reason why doing what you are trying would be better. > Another question is how to realize that our functionality is a built in > function which can be accesed by .-opertator (e.g. > E.integral_points(...) with E an elliptic Curve) > For that the simplest way is to insert your code into the class definition of ell_rational_field in the Sage source tree (which conatins .py files so you would need ** and not ^ etc). I think there might be another way to do it but since we want your code to be part of Sage when it is fully writtemn and tested, and that is where it will go, you might as well put it tere right away. I hope this helps. I suggest that any Sage questions you have are asked via sage-devel, and mathematical questions about the algorithms can be sent just to me. > At the moment we insert the LLL-trick as last step. > After that we are planning to test our algorithm and insert > error-handling where it is missing. > Good. Keep a list of good test cases, since it will be a requirement before your code is incorporated into Sage the the functions are folly documented with docstrings and doctests. John > > Best wishes > Michael & Tobias > > > John Cremona schrieb: >> Dear Michael and Tobias, >> >> That is a good plan. I also think you should divide up your >> implementation over Q into two stages: integral points, and then >> S-integral points. The latter is definitely harder than the former. >> >> For other reading: you should definitely look at the thesis of >> Emmannuel Herrmann. I have not read it since my German is weak, but I >> suspect that will not be a problem for you! He is the person who >> implemented this (over Q) in Magma. Secondly, over number fields >> there is a paper by N.P.Smart which should be useful. He also wrote a >> book (called something like "A cookbook of methods for solving >> Diophantine equations" - not his book on elliptic curve cryptogaphy!) >> and I seem to remember that has a chapter on this, but I might be >> wrong. (Sorry: I am on leave this year and do not have access to most >> of my books). >> >> I hope this helps. I look forward to hearing how you get on. >> >> John Cremona >> >> 2008/4/23 Michael Mardaus <[EMAIL PROTECTED]>: >> >>> Dear John Cremona, >>> >>> Mr. Mueller-Stach forwarded your email concerning the sage >>> s-integral point project. >>> After a meeting last week with Mr. Mueller-Stach, we decided to >>> first contact you and then start programming. >>> So far we would start with the implementation of the algorithms >>> presented by H.Cohen in his Book "Number Theory Vol.I Tools and >>> Dioph. Eq." and the paper written by Pethö. >>> After that, we hope it will work, we would go on with number fields. >>> What do you think about this plan? Do you recommend some other >>> papers? >>> >>> Thank you for offering your assistance. >>> (We think there will be some questions ;) ) >>> >>> Best wishes >>> Michael and Tobias >>> -- >>> Michael Mardaus >>> mailto:[EMAIL PROTECTED] >>> >>> Tobias Nagel >>> mailto:[EMAIL PROTECTED] >>> >>> >>> -------- Original Message -------- >>> Subject: Re: Projects >>> Date: Thu, 17 Apr 2008 09:59:09 +0200 >>> From: John Cremona <[EMAIL PROTECTED]> >>> To: Mueller-Stach, Prof. Dr. Stefan <[EMAIL PROTECTED]> >>> CC: William Stein <[EMAIL PROTECTED]> >>> >>> [I am CC'ing William since it was nto clear that your email went to him >>> too.] >>> >>> This is great news. No-one else is doing this and so -- as far as I >>> am concerned -- the problem is duly "reserved" for your students. >>> >>> I would be happy for the students to ask me questions as they do this, >>> though I will not necessarily know the answers! >>> >>> Best wishes, >>> >>> John >>> >>> 2008/4/16 SMS <[EMAIL PROTECTED]>: >>> > Dear John, dear William, >>> > >>> > you suggested to write code for students for S-integral points with >>> > the algorithm outlined above mainly by John. >>> > The two students I mentioned (Tobias Nagel, Michael Mardaus) are now >>> > ready to start working after they went through >>> > some papers of Smart/Stephens and Peth"o et al. describing the >>> > algorithm. >>> > >>> > Should we let them become members here as well and discuss with you >>> > and others about possible upcoming problems and details ? >>> > >>> > I would like to ask to reserve the problem for them so that they can >>> > work on it for their diploma thesis. The plan is to finish >>> > writing code during the coming weeks and work on the thesis after >>> > that. I hope that the problem hasn't been attacked by anybody else >>> > yet. >>> > >>> > Best regards, >>> > >>> > Stefan >>> >> . >> >> > > --~--~---------~--~----~------------~-------~--~----~ To post to this group, send email to [email protected] 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://www.sagemath.org -~----------~----~----~----~------~----~------~--~---
