On Mon, Feb 13, 2012 at 7:49 PM, someone <someb...@bluewin.ch> wrote: > Hi, > >> >> > Heads up: that's a pretty tough one. But if you do feel that you >> >> > are up to it, it would be a great thing to have. >> >> >> >> The fact that it's a tough one only makes me feel more >> >> interested :-) Here >> >> https://github.com/sympy/sympy/wiki/gsoc-2012-Ideas I can see that >> >> there is some bibliography provided for Karr algorithm. I'll read >> >> whatever I can find and report my experience with understanding >> >> the stuff. >> > >> > I collected a great deal of papers related to this subject. I'm very >> > interested in the algorithms but sadly do not have (yet?) the >> > deep enough understanding of the algebraic concepts behind it. >> > (I started reading about the Risch algorithm some time ago. >> > Because I feel that the literature there is much more sorted.) >> >> Oh, I see. I can't guarantee that my knowledge is sufficient, but I'm >> certainly willing to try. Could you maybe recommend me a starting >> point in the literature? Or are the references suggested on the GSoC >> ideas page good enough from your point of view? > > Maybe chapter 2 of "Algebraic Extensions for Symbolic Summation", > the thesis of Burçin Eröcal (1st google link). It should provide > a first entry to the subject. (Most other information I have are > research papers which are an unsuitable entry point, the theory > is split up into many tiny pieces :-/) > > Probably you can also find something in "Symbolic Summation in > Difference Fields", the thesis of Carsten Schneider. (Although > his research goes way beyond the basic principles.) > >> > BTW: There is someone in the sage community who started some >> > work on Karr a few years ago [1]. But I could not find out what the >> > current state of his work is. (I *think* it's by far not finished >> > yet. And even if it would be, then maybe you could focus on the >> > various extensions done by Schneider. But maybe this fact rules out >> > the Karr topic to be a GSOC project?) >> > >> > [1]: http://wiki.sagemath.org/days20.5/schedule >> >> Hm, I could ask them directly. Would it be appropriate if I state the >> reasons for asking, or should I appear on their mail list with just a >> question? (I'm not sure what the relationship between SymPy and Sage >> communities is.) > > Sympy is used by sage. But I can not say much more than that.
The basic idea behind Sage is that they have taken a bunch of computer algebra systems and pulled them together into a unified interface. SymPy is among these systems. I actually do not know to what degree SymPy is used by default, if at all, though I know there is a way to make SymPy the default if you want. Our communities are separate for the most part, though there are people who participate in both (I personally do not really participate in the Sage community, so I can't say much more than that). But from what I seen, the Sage community is friendly, and so is ours, so I wouldn't worry about it. If you want to reuse exact code from Sage, one thing that you should be aware of is that their code is licensed under the GPL, whereas ours is BSD, so you will have to ask for permission by the author(s) to relicense it (sometimes this is not a problem, but sometimes it is either infeasible due to the number of authors, or someone simply does not want to relicense his code). And even if you got it, depending on how it was written it could be very nontrivial to rework the code to work with SymPy, so that it might be better just to do it from scratch. But it's worth a shot to at least look at it if it's there, and anyway, a reference implementation is always nice. Aaron Meurer > >> > I would rate symbolic summation/products to be one of the top-most >> > items on the list. BUT I do not speak for the others neither do I >> > have a good overview. So please consider this to be my personal >> > (miss)rating. >> >> I see. Thank you for your feeback! :-) > > I hope that I can help you at least a little bit with > the selection of your GSOC topic. > > -- > You received this message because you are subscribed to the Google Groups > "sympy" group. > To post to this group, send email to sympy@googlegroups.com. > To unsubscribe from this group, send email to > sympy+unsubscr...@googlegroups.com. > For more options, visit this group at > http://groups.google.com/group/sympy?hl=en. > -- You received this message because you are subscribed to the Google Groups "sympy" group. To post to this group, send email to sympy@googlegroups.com. To unsubscribe from this group, send email to sympy+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/sympy?hl=en.
