On Tuesday, May 28, 2013 5:46:13 AM UTC-7, Harald Schilly wrote: > > The following is a cross-post from sage-announce and other channels. > Apart from these three projects, there are also 5 very exiting ones for > Lmonade <http://www.lmona.de> (project summaries at their GSoC > page<http://www.google-melange.com/gsoc/org/google/gsoc2013/lmonade>) > and furthermore in the broader "world of > Python"<http://www.google-melange.com/gsoc/org/google/gsoc2013/python>, > also quite many for > SymPy<http://www.google-melange.com/gsoc/org/google/gsoc2013/sympy>and > scikit-learn. > > Sage <http://www.sagemath.org/> is pleased to announce three Google > Summer of > Code<http://www.google-melange.com/gsoc/org/google/gsoc2013/sage>projects for > 2013. They focus on speed improvements of symbolic functions, > simplifying the distribution and installation procedure on Debian/Linux and > ubiquitous accessibility of Sage on the Android platform. > > Mathematical Functions Library > Eviatar Bach <http://www.phas.ubc.ca/%7Eeviatarb/> – University of > British Columbia in Vancouver, Canada > (Mentor: Flavia Stan, Backup: Burcin Erocal) > > Sage interfaces with multiple third-party libraries, such as MPFR, GSL, > GP/PARI, mpmath, and Maxima, for numerical evaluation of special functions. > There are significant discrepancies between these backends in the > performance for numerical approximations of the same expression. An initial > benchmark reveals, for example, that calculating spherical_bessel_J(1, 5.2) > with SciPy is over 100 times faster than with Maxima. > > The project has the following goals: > > 1. develop a benchmark framework to determine which backend should be > used by default to evaluate a special function over a specific domain, > > This sounds like a really bad idea for 2 reasons. 1. none of the backends are stationary. If someone comes up with a spherical_bessel evaluator that is 100X faster yet again than SciPy, but is in Maxima, you are losing. 2. To determine over an arbitrary span of floats which program is most accurate and fastest requires a fairly sophisticated set of tests. For example even a function like sine can be delicate to evaluate, say at a high integer multiple of pi. And how do the functions respond at singularities? Just generating random arguments is not sensible. Oh, for some programs you may need to figure out what to do with unbounded inputs (integers, bigfloats).
> > 1. > 2. create symbolic wrappers for all the special functions that can be > evaluated numerically by a package included in Sage, > > Um, I'm not sure what is required here, but maybe just bookkeeping?? > > 1. > 2. create a data structure for generalized hypergeometric functions > and extend the symbolic wrappers to obtain representations in terms of > generalized hypergeometric functions when possible, > > huh? Wouldn't it always be possible to express generalized hypergeometric functions as generalized hypergeometric functions? If you mean to simplify them, whose algorithm are you going to use? Or did you not know about such things? > > 1. > 2. implement closure properties for holonomic functions as a next step > to improve the symbolic processing of special functions in Sage. > > > . > Overall improvement of the Sage Android application > Rasmi Elasmar > (Mentor: Volker Braun, Backup: Harald Schilly) > > Although there are already some existing efforts, Sage is still not easily > accessible from the Android platform. The Sage Cell client/server > infrastructure is an already existing step towards running Sage on a server > and communicating back the results. The aim of this proposal is to fix, > improve and update the Sage Android application to include new features and > functionality, as well as an improved interface for simpler and improved > usability. Android's new "Holo" style, sharing of calculations and results, > and much more waits to be realized on Android for Sage. > > This project, and the one below, suggest that people are going to continue to ignore the elephant not in the Operating System Room, namely native Windows XP, Vista, 7, 8 ... Get Sage ready for Linux distributions > Felix Salfelder – Goethe Universität, Frankfurt, Germany > (Mentor: Tobias Hansen, Julien Puydt, Jeroen Demeyer & John Palmieri ) > sage-devel > discussion<https://groups.google.com/forum/?fromgroups#%21topic/sage-devel/1HGbf4EZGb0> > > The aim of this project is to detach the build process of Sage ("the > software") from Sage ("the distribution"). The goal is a build system that > works within the context of Sage as well as for any GNU/Linux distribution > that ships the dependencies for Sage. Distributions that already ship Sage > packages or plan to do so are Fedora and Debian. This project is an > important step towards making Sage packages in GNU/Linux distributions > feasible. > > > Sage warmly welcomes all three new students and wishes them all the best > to learn something new and make an impact in Sage's future developments! > -- You received this message because you are subscribed to the Google Groups "sage-devel" group. To unsubscribe from this group and stop receiving emails from it, send an email to sage-devel+unsubscr...@googlegroups.com. To post to this group, send email to sage-devel@googlegroups.com. Visit this group at http://groups.google.com/group/sage-devel?hl=en. For more options, visit https://groups.google.com/groups/opt_out.
