From gutsche at mathematik.uni-siegen.de Tue Jan 9 10:46:38 2018
From: gutsche at mathematik.uni-siegen.de (Sebastian Gutsche)
Date: Tue, 9 Jan 2018 11:46:38 +0100
Subject: [GAP] Jupyter in GAP and other CAS: Registration open
Message-ID: <23191100-9f63-ef7c-109a-dcaba91caf15@mathematik.uni-siegen.de>
Dear all,
on the website http://gapdays.de/gap-jupyter-days2018/ it is now
possible to register for the "Jupyter in GAP and other CAS" workshop.
The workshop takes place in St Andrews, June 4th - June 8th 2018.
Everybody who wants to work on Jupyter related things in CAS is welcome.
Please feel free to spread the link.
Workshop description:
Many new technologies for interactive documents, such as the GAP native
Jupyter Kernel, MyBinder, ThebeLab have been developed recently.
The aim of this workshop is to bring together people who are developing
or using these technologies, and people who want to use them. While
combining the use of GAP and Jupyter is the main focus of this workshop,
people developing Jupyter or using Jupyter to access other software are
of course welcome to attend. The topics include (but are not limited to):
* The GAP JupyterKernel
* JavaScript-Visualizations using Jupyter
* Using Thebe for interactive manuals
* Developing teaching materials with Jupyter, and publishing them using
MyBinder
* Writing academic publications using MyBinder and Docker images, to
make all computational results and all examples fully and easily
reproducible.
The workshop is meant to collect ideas, start work on projects, provide
tutorials for use cases, etc.
Best regards,
Markus & Sebastian
From frank.luebeck at math.rwth-aachen.de Sun Jan 14 09:29:49 2018
From: frank.luebeck at math.rwth-aachen.de (Frank =?iso-8859-1?Q?L=FCbeck?=)
Date: Sun, 14 Jan 2018 10:29:49 +0100
Subject: [GAP] [GAP Forum] efficient factorisation of integers in
computing Abelianisation
In-Reply-To:
References:
Message-ID: <20180114092949.GC13782@localhost.localdomain>
On Fri, Jan 12, 2018 at 09:11:59AM +0100, Jean RAIMBAULT wrote:
> Hello all,
>
> I am currently trying to use GAP to compute the first homology of some
> large-index congruence subgroups in arithmetic Kleinian groups. Large primes
> often occur in the order of the torsion subgroup of such homology and this
> causes the computation to be stalled by the inefficiency of the factoring
> method ("FactorsInt") use in the function "AbelianInvariants".
>
> For example a computation lasted for more than three hours (after the group
> presentation was obtained) because of the failure to factor the integer
>
> 105023714400084996151549919196232398687915731 = 8882788338909318083641 *
> 11823282329046290928491
>
> (the number of "RhoTrials" kept augmenting but the algorithm failed to
> terminate). On the other hand the factorisation above was almost immediately
> computed by the function "Factors" after loading the package "FactInt".
>
> So I was wondering whether there is a simple way to force the function
> AbelianInvariants to use the latter method of factorisation, or a package
> with a function computing abelianisation of a group when large primes occur
> in the invariants.
Dear Jean Raimbault,
Can you try to load the 'FactInt' Package before calling
'AbelianInvariants'? The function 'FactorsInt' should call 'Factors' if the
'FactInt' package is loaded.
Best regards,
Frank L?beck
--
/// Dr. Frank L?beck, Lehrstuhl D f?r Mathematik, Pontdriesch 14/16,
\\\ 52062 Aachen, Germany
/// E-mail: Frank.Luebeck at Math.RWTH-Aachen.De
\\\ WWW: http://www.math.rwth-aachen.de/~Frank.Luebeck/
From alexander.konovalov at st-andrews.ac.uk Mon Jan 22 14:57:16 2018
From: alexander.konovalov at st-andrews.ac.uk (Alexander Konovalov)
Date: Mon, 22 Jan 2018 14:57:16 +0000
Subject: [GAP] Workshop on interfacing (math) software with low level
libraries
Message-ID:
----- Forwarded message from "Nicolas M. Thiery" -----
Date: Mon, 22 Jan 2018 11:57:01 +0100
From: "Nicolas M. Thiery"
To: participants at opendreamkit.org
Subject: Workshop on interfacing (math) software with low level libraries
Dear OpenDreamKit participants,
This is to announce an ODK workshop on "Interfacing (math) software with
low-level libraries" next Spring (April?) in Cernay near Paris:
https://github.com/OpenDreamKit/OpenDreamKit/issues/251
We should fix the dates soon, so please fill in the poll before
January 31st if you consider joining:
https://framadate.org/RBpcIXSHU6p8Wcu1
Details:
(Math) Computational systems face a tension between using high level
languages (e.g. Python) for expressivity, ease of use and prototyping,
and low-level languages (e.g. C/C++) for power and speed, and also for
modularity (using existing libraries, or writing reusable ones). To
resolve this tension, many approaches have been explored in the recent
years, and the frontier between the two worlds is becoming
increasingly blurry.
The purpose of this workshop is to bring together developers to share
expertise, seek collaboration venues, and get into concrete action.
This is quite bold. The focus on math software should keep this
manageable, while providing a large enough variety of solutions and
use cases.
- Developers of "binding systems" such as cppyy, pybind11, Boost Python
- Developers of "compilers" such as Cython, Pythran, Numba
- Developers of interactive C++ environments (cling, xeus-cling, xtensor, ...)
- Developers of (math) libraries in a low level language that wish to
make their code accessible to a variety of users (e.g.
libsemigroups, or low-level combinatorics HPCombi, number theory and
arithmetic FLINT; in general developers of C-level interfaces to
various systems: libSingular, libgap, cypari, cypari2, giacpy,
PyNormaliz, Linbox, meataxe;
- Developers of systems like GAP, SageMath, Oscar, Mathemagix, ROOT
that make a heavy use of such technologies
- Developers of programming languages like Julia
- ...
Organizers:
- Vincent Delecroix, Serge Gelton, Florent Hivert, Nicolas Thi?ry
Funding:
OpenDreamKit should be able to fund all the local expenses (as in
previous workshops in Cernay), the travel expenses of ODK members, and
the travel expenses of some invited people.
Cheers,
Nicolas
--
Nicolas M. Thi?ry "Isil"
http://Nicolas.Thiery.name/
----- End forwarded message -----