On Thu, Mar 20, 2014 at 1:40 PM, Peter Petrov <[email protected]> wrote: > Thanks for all the replies. This was so fast. You guys are great. I will > look into the references pointed out by Ondřej and try to narrow down a > concrete problem. What Matthew said is exactly my idea. Working on a physics > related problem will keep me interested and motivated to keep going, but I > will be thinking of implementing constructs in a general way to be used in > other problems. I think I will either focus on something tensor related > (Gamma matrices or some type of functionality which automatically > manipulates indices in different group representations), or maybe go with > the Feynman diagram suggestion of Ondřej. As Stefan pointed out The Feynman > diagram visualization is not really generalizable, but is still very > important for a big community. There might be some general topology > constructs there as well. > > Right now I started working on an issue to try and fix before the deadline. > I am looking at https://github.com/sympy/sympy/issues/7134. There have been > no replies for some months. Should I just post my thought in that thread and > see if anyone jumps in. I think I have an idea of a basic (probably not very > good, but hopefully working) resolution. At this point I am just trying to > have something to submit as a pull request, but I am a little stuck on some > technical details. I know its a simple issue, but I have to start somewhere > right.
If you want to quickly start with something, pick some issue here: https://github.com/sympy/sympy/issues?labels=Easy+to+Fix&milestone=&page=1&state=open Ondrej > > Thanks again for all the comments! > > > On Thursday, March 20, 2014 2:34:24 PM UTC-4, Matthew wrote: >> >> My thoughts on what's written so far are different from Ondrej's. I am >> less excited by physics applications and more excited by the tools necessary >> to enable the expression of physics applications. The extent to which a >> domain specific project like this can be broken into a generally applicable >> component (some mathy or algorithmic bit) and a domain specific application >> (some physics thing) is good. This increases the applicability and >> relevance of a summer project to a wider audience. >> >> >> On Thu, Mar 20, 2014 at 11:25 AM, Ondřej Čertík <[email protected]> >> wrote: >>> >>> On Thu, Mar 20, 2014 at 12:17 PM, Ondřej Čertík <[email protected]> >>> wrote: >>> > Hi Peter, >>> > >>> > I read through your ideas. First of all, I started SymPy as a >>> > theoretical physics student myself, >>> > and I wanted to automate the General Relativity as well as high energy >>> > QFT calculations. I am still >>> > very interested in that, but there are a lot of tough problems and >>> > parts that need to be in place. >>> > >>> > You need to be able to do integrals, handle potentially large >>> > formulas, tensor manipulation and simplification >>> > (e.g. gamma matrices), and so on. It's not easy at all, but we've done >>> > a long progress since the time I started >>> > SymPy in 2007 or so. Most of these things are in place, in some form. >>> > In order to efficiently handle very large >>> > expressions, I started developing CSymPy about half a year ago >>> > (https://github.com/certik/csympy), this >>> > will come very handy as well for these applications. >>> > >>> > The best way to get some ideas of what can be done is to look into >>> > existing packages, they are pretty much >>> > all in Mathematica. In fact, most theoretical physicist just use >>> > Mathematica. And let's be frank, it's currently the >>> > best if you just care about getting the results. There is also GiNaC >>> > (http://www.ginac.de/) that can be used for some of the >>> > high energy stuff, but CSymPy can now do pretty similar things, >>> > sometimes faster. So there is: >>> > >>> > http://www.feyncalc.org/ >>> > >>> > there are all these various things people wrote for Mathematica: >>> > >>> > @article{huber2012crasydse, >>> > title={CrasyDSE: A framework for solving Dyson--Schwinger equations}, >>> > author={Huber, Markus Q and Mitter, Mario}, >>> > journal={Computer Physics Communications}, >>> > volume={183}, >>> > number={11}, >>> > pages={2441--2457}, >>> > year={2012}, >>> > publisher={Elsevier} >>> > } >>> > >>> > @article{huber2012algorithmic, >>> > title={Algorithmic derivation of functional renormalization group >>> > equations and Dyson--Schwinger equations}, >>> > author={Huber, Markus Q and Braun, Jens}, >>> > journal={Computer Physics Communications}, >>> > volume={183}, >>> > number={6}, >>> > pages={1290--1320}, >>> > year={2012}, >>> > publisher={Elsevier} >>> > } >>> > >>> > But the advantage of SymPy is that the whole stack is opensource, and >>> > SymPy is just a library, so it better integrates >>> > with things like IPython Notebook and you can create the whole >>> > application in it. For example, the physics.quantum >>> > module has some good stuff, that plays together much better than >>> > packages in Mathematica. Another great application is PyDy. >>> > >>> > So it would be really nice to have the project that you describe. You >>> > should have a look at work done by Francesco Bonazzi >>> > regarding the gamma matrices: >>> > >>> > https://github.com/Upabjojr >>> > https://github.com/sympy/sympy/pull/2601 >>> > >>> > He has lots of PRs, closed and open. It's nontrivial. And those are >>> > just the gamma matrices. I think Francesco's goal >>> > could be summarized by your proposal, and he's done many months worth >>> > of work on it already. So the scope is just huge. >>> > So there is plenty of things that could be done for the summer. >>> > >>> > One of the things is for example just the Feynman diagrams generator >>> > for various Lagrangians. I am sure there must be some >>> > packages that do that, but it'd be nice to integrate this with SymPy >>> > and create nice IPython Notebooks that generate all the correct >>> > diagrams, for example from Peskin & Schroeder. This will be good for >>> >>> I.e. this would involve some classes for representation of Feynman >>> diagrams, >>> that would also know how to nicely visualize themselves in the IPython >>> Notebook, >>> and then code that generates them for various interactions. >>> And so on. >>> >>> For other ideas, I have some derivations of various things here: >>> >>> http://theoretical-physics.net/dev/src/quantum/qft.html#standard-model >>> >>> that could be automated. For example one can reformulate the problem >>> using >>> Green's functions and so on. >>> >>> Ondrej >>> >>> > pedagogical reasons, as well as computations. In general, >>> > good applications in my opinion are providing automatic symbolic >>> > solutions to various exercises from books. >>> > >>> > Another thing is of course Regularization and Renormalization. >>> > >>> > I would suggest you to figure out something, that can be finished >>> > during a summer and that would provide something useful, >>> > on it's own. So that you can create nice examples out of it. Then you >>> > can continue working on some other things after the summer. >>> > >>> > Ondrej >>> >>> -- >>> You received this message because you are subscribed to the Google Groups >>> "sympy" group. >>> To unsubscribe from this group and stop receiving emails from it, send an >>> email to [email protected]. >>> To post to this group, send email to [email protected]. >>> >>> Visit this group at http://groups.google.com/group/sympy. >>> To view this discussion on the web visit >>> https://groups.google.com/d/msgid/sympy/CADDwiVCdh9JHMZ%3DQeUMK1-xrcXhjOY4JraWcs5OmnrzsJnZRZg%40mail.gmail.com. >>> For more options, visit https://groups.google.com/d/optout. >> >> > -- > You received this message because you are subscribed to the Google Groups > "sympy" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected]. > To post to this group, send email to [email protected]. > Visit this group at http://groups.google.com/group/sympy. > To view this discussion on the web visit > https://groups.google.com/d/msgid/sympy/db799754-02a6-4e35-93a3-8bee543b8882%40googlegroups.com. > > For more options, visit https://groups.google.com/d/optout. -- You received this message because you are subscribed to the Google Groups "sympy" group. 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