Coding sprints for Free and Practical Software for Algebraic Combinatorics 2019

Status reports & Testimonials

See trac tickets with fpsac2019 keyword.

  • Many beginners got their first experiences with the sage development process. The tutorials and exercises helped a lot to get started and to gain confidence with git, git trac, sage development, …

  • The official talks showed the participants how to use free and practical software for their own research.

  • The diversity of the group allowed us to work on many different projects and learn from each other.

  • Trying to resurrect Viviane's code for multivariate polynomials.

  • Finalization of symmetric functions tutorial

  • Integration of a linear time algorithm for enumeration of all distinct squares in a word #28182 (pending review) and #23573.

  • For future organisers: Providing good network connection is hard. Eduroam alone is not enough to provide stable connections. Think about backup solutions.

Hopf algebras

Hopf and other superalgebras as their own hierarchy (#25603)

Travis Scrimshaw, Darij Grinberg, Nicolas Thiéry …

Sprint tonight 20:30

A, B, C: Super algebras

tensor([A, B, C]) -> SuperAlgebras().SignedTensorProducts()

tensor([A, B, C], category=Algebras())

SuperAlgebras() subcategory of Algebras().Graded()
SuperAlgebras().TensorProducts() subcategory of Algebras().Graded().TensorProducts()

C -> C.default_tensor_construction

Modules().SubcategoryMethods.tensor = tensor
SuperAlgebras().SubcategoryMethods.tensor -> signed_tensor

tensor([A,B,C]) -> find the meet category D, and build D.tensor([A,B,C])

Enable A.tensor(B,C) ???

SuperAlgebras().SignedTensorProducts() is a subcategory of Modules().Graded().TensorProducts()

Combinatorics

RSK reviewing (#27852), coRSK (#25070).

Darij Grinberg, Anne Schilling, Travis …

https://github.com/darijgr/sage-subspace/

Semistandard Multiset Tableaux and Crystal on Semistandard Set Valued Tableaux (#28134)

Wencin Poh, Jeremy Meza, Anne Schilling, Kyle Meyer …
Sprint at 20:00

Oriented Matroids

Aram Dermenjian

Created an (alpha) package for oriented matroids.

https://github.com/thecaligarmo/oriented_matroids/

Framework for finite dynamics

Darij Grinberg, Tom Roby, reviewed by Travis Scrimshaw
was finished off during these SageDays
https://trac.sagemath.org/ticket/24128

Visualization of combinatorial objects

Henri, Abolape

Using and extending Sage-Combinat-Widgets

Abolape

Explore the use of sage-combinat-widgets for teaching and research purposes.
E.g. implement a Robinson-Shensted App

Presenter: Odile Bénassy + …

Installation: Mee Seong, Harrison

​​​​sage -pip install sage_combinat_widgets

Workshop Tuesday from 10:30 and from 15:30 – room 202

Polyominos

by Henri D -> 1 PR accepted, 2 will be accepted

Packed words

by Hugo M -> work in progress

Creating paths between widget cells

by Can OO -> work to be started

Symbolic Computation

Differential-difference algebra

Getting a more natural implementation for differential rings in a general way, adapting the strucre to general rings, fields and the coercion system in Sage.

Or just learn with precision how it is already in Sage.

Antonio, Mee Seong

Documentation and tutorial

Symmetric function tutorial

Merge the new symmetric function tutorial into SageMath

Pauline Hubert, Anne Schilling?

Polish the Start here tutorial and merge it into SageMath?

Nicolas, Antonio,…

Review More SageMath Tutorials and see what could be merged into SageMath

Nicolas, Antonio, Mee Seong,…

Dynamical Algebraic Combinatorics Tutorial

Tom Roby (creating rst files, just getting started)

Subspaces

Darij Grinberg, Nicolas T.

Parallelization

Pauline (problem solved !), Tomer (Improve zetalib)

KLR-algebras?

Type q(n+1)-crystal structure on Shifted Prime Tableaux

Basically define f_{-1} operator on set of shifted prime tableaux and its tensor product rule

Wencin Poh, Eric Marberg?, Ines Rodrigues

King Symplectic Tableaux and Sheats Bijection (#26143)

Implement a SymplecticTableau object for Kashiwara-Nakashima tableaux and King tableaux that doesn't go through (slow) crystal algorithms. There is already a ticket, but it's colored red so I think that means something is very wrong…

Jeremy Meza, João Santos

Package dd_functions

Steps:

  • make it available on a public repo
  • make it a Python package (see the setup.py of https://github.com/sagemath/sage_sample)
  • Add a demo notebook
  • Add Binder configuration (see the Dockerfile of sage_sample) + binder link/badge from the README
  • Publish on pipy
  • Configure sphinx for the documentation
  • More tests and documentation
  • Write a tutorial
  • Setup continuous integration (see sage_sample)
  • ? Merge into SageMath

Do you want to help? Contact me (Antonio Jimenez-Pastor)

Package zetalib

Python 3 compatibility and a little improvement to logging.
We should add a demo notebook with Binder support.

Add number of subgroups method to AbelianGroup

See trac #28136 for future addition of number_of_subgroups(). Ready for review!

On the way we discovered bugs for simple things in subgroups of a subgroup of an abelian group. See trac #28150 for details.

Tomer

Add a function that gives the complementary of a subword

See trac #28160 for details. The ticket has a positive review and will soon be closed. Here are some examples that I got running the algorithm on French and English dictionaries.

French

albatros bars alto
ambiance banc amie
banlieues bleue anis
botaniste tante bois
botaniste botte anis
céramiques émis craque
craignent crin agent
criminel miel crin
doctrine dote crin
versatile veste rail
voitures ours vite

English

greatest rest gate
vertices vets rice
violates vile oats
facility fail city
threaten then rate

Add yours!

Select a repo