# Sage-Combinat: enhancing Sage as a toolbox for computer exploration in algebraic combinatorics

Sage-Combinat is a software project whose mission is: **to improve the open source mathematical system Sage as an extensible toolbox for computer exploration in (algebraic) combinatorics, and foster code sharing between researchers in this area**.

In practice, Sage-combinat is a collection of branches on top of Sage, developed by a community of researchers. The intent is that most of those branches get eventually integrated into Sage as soon as they are mature enough, with a typical short life-cycle of a few weeks. In other words: just install Sage, and you will benefit from all the Sage-combinat development, except for the latest bleeding edge features.

## NEWS

Experimental Sage notebook with the Sage-Combinat patches applied

A new poster for Sage-Combinat!

## Past news

August 14-17, 2014 Sage Days 60, Chennai, India

April 7-11, 2014 Sage(-Combinat) Days 57, Cernay, France

November 4-8, 2013 Sage(-Combinat) Days 54, University of California at Davis, USA

- Organized by Dan Bump, Anne Schilling and Travis Scrimshaw

June 17-21, 2013 Sage(-Combinat) days 49, in Orsay as satellite event to FPSAC'13

- Organized by Alejandro Morales, Anne Schilling, Nicolas M. Thiery

January 28 - May 3, 2013: ICERM Semester Program on "Automorphic Forms, Combinatorial Representation Theory and Multiple Dirichlet Series", with a strong Sage and Sage-Combinat component, ICERM, Brown, USA

February 11-15, 2013 Sage Days: Multiple Dirichlet Series, Combinatorics, and Representation Theory, ICERM, Brown, USA

- Organized by Franco Saliola, Anne Schilling, Nicolas M. Thiery

January 21-25, 2013 Online Databases:from L-functions to combinatorics, Edinburgh

Organized by Paul-Olivier DeHaye, Nicolas M. Thiery.

October 29 - November 9, 2012: CIMPA summer school Discrete mathematics : combinatorial, dynamical and algorithmic aspects, with a strong Sage and Sage-Combinat component, Bobo Dioulasso, Burkina Faso

July 9-13 2012: Sage(-Combinat) Days 40: Algebraic Combinatorics, IMA, Minneapolis, USA

- Organized by Gregg Musiker, Franco Saliola, Anne Schilling, Nicolas M. Thiery.

May 7-11 2012: Sage(-Combinat) Days 38: algebraic combinatorics and the representation theory of algebras, Centre de recherches mathématiques, Montréal, Canada

April 18-th 2012: Coxeter/Cluster algebra afternoon at the Paris Sage User Group meeting

February 8-10 2012: Sage and cluster algebra workshop, University of Hannover

February 6-10 2012: Sage-Combinat Days Cernay 2012

March 19-23 2012: EJC du GDR-im a Rennes site officiel

May 2-6, 2011: Sage Days 30: Combinatorics (Schubert calculus, cluster algebras) and Number theory (integer vectors, multidimensional digit representations) in Acadia University, Wolfville, Nova Scotia, Canada

- Organized by Eva Curry and Hugh Thomas.

January 17-19, 2011: Sage days 28: dynamics, geometry, and analytic combinatorics in Orsay

July 10, 2010: First release of Calcul Mathématique avec Sage

- A 315 pages open source french introductory book on computational mathematics, illustrated in Sage, and including a 35 pages chapter on combinatorics (and soon one on graph theory).

July 7-15, 2010: Affine Schubert Calculus workshop and summer school in Toronto

- It includes several Sage and Sage-Combinat sessions. Organized by Anne Schilling and Mike Zabrocki.

June 14-18, 2010: Joint Sage-Combinat and Chevie Workshop in Orsay

May 3-7, 2010: Sage Days 20.5 in Toronto

Organized by Nantel Bergeron, FrancoSaliola and Mike Zabrocki, again with a serious algebraic combinatorics slant

February 22-26, 2010: Sage days 20

The thematic month MathInfo 2010 at CIRM, Marseille included a Sage days week. FlorentHivert, NicolasThiéry, and FrancoSaliola were among the organizers and there was a serious combinatorics slant.

July 25-29, 2009: *-Combinat 2009

We held an International Sage Workshop on Free and Practical Software for Algebraic Combinatorics at RISC, Linz, Austria, right after FPSAC'09

May 25th, 2009: The Sage-words library demonstrated at the 2nd Canadian Discrete and Algorithmic Mathematics Conference CanaDAM'09 Sage worksheet, PDF.

April 15th, 2009: Software demonstration accepted for FPSAC'09 PDF, LaTeX Source LaTeX bibliography

January 26-30, 2009: Sage-Combinat Workshop in Orsay

- 2008-06-19: MuPAD-Combinat join forces with Sage
Sage-combinat was born as a partial port of MuPAD-Combinat. After months of discussions and experiments, an enthusiastic consensus emerged in the MuPAD-Combinat community to join Sage. Sage-combinat henceforth became the natural successor of

`MuPAD-Combinat`.

- The transition was a massive investment (and is not yet completely over): seven years of hard work to port over! However a lot of experience was gained since 2000, and most of the design was pretty clear, and we could *share* the work.

## Who are we? What is Sage-Combinat used for?

Cite Sage-Combinat when you use it for research publications.

Cool pictures we produced with Sage-Combinat for our research

## How to participate and contribute

### Communication

- Join our mailing lists:
- Announcement mailing list (to come)
sage-combinat-devel: Developers' mailing list

sage-combinat-commits: A low traffic mailing list which receives an automatic notice whenever a sage-combinat related ticket is modified (and eventually whenever a commit is done on the patch server).

sage-combinat-days: Mailing list for the organisation of Sage-Combinat days

Check the road map and current status

Post bug reports, suggestions, patches on the Sage-Combinat trac server or on the mailing list.

### Code

Since Sage 6.0, the development workflow has been reworked in depth, and we are in the progress of migrating the extensions as git branches. Here are some useful links:

The Sage-Combinat extensions used to be managed as a collection of patches on our patch server, using a so-called mercurial queue. Quite some stuff below is thus outdated, and will be progressively replaced by information on the new workflow.

Browse the Sage sources with the Sage-combinat patches applied (only useful for Sage version prior to sage-6.0)

Developing for Sage-Combinat on Windows: Sage Development on Windows.

### Design

Have a look and participate to design discussions.

Contribute to the list of quirks and weirdness issues in the

`*-Combinat`design.

### Documentation

Browse the Sage documentation with the Sage-combinat patches applied

And in particular the Thematic tutorials

Mercurial server for miscelleanous files and documents (Usage instructions)

## Links

The Combinatorial Software and Databases web page maintained by Christian Krattenthaler