Sage Days 49 Coding Sprint Projects

Combinatorics

• Implementing Stanley chromatic symmetric function for posets

  Mathieu, Eric, Alejandro, Chris, Nathann, Yan

• Implementing boards for rook placements, Le diagrams (#14127)

  • implementing Le diagrams
  • include CombinatorialMaps if possible
  • adding documentation and doctests

  Alejandro, Kevin (testing/doctests), Bruce, Salvatore, Emily, Federico

• Flow polytopes from permutation matrices and alternating sign matrices (#14654)

  Jessica, Alejandro, Nathann, Emily, Laura

• Implementation of k-tableaux and k-charge (#12250, #14776)

  Anne, Mike, Tom D, Nate, Avi

• Combinatorial actions and orbit averages on posets, order polytopes, and rational functions

  Tom Roby, Darij, Jessica, Kevin, Emma, Emily

• Multivariate power series / lazy

  Marguerite, Mathieu, Florent, Marc

• Hypergraph visualization

  Nathann

• Combinatorial Species

  Martin Rubey, Bruce, Mike, Florent, Tom D., Marguerite Thursday and Friday only

  • code cleanup
  • generation of unlabelled objects for composition and functorial composition via a group action framework
  • multisort species (multivariate formal power series would be useful for that)
  • add code by Andrew for Gamma-species
  • support operations from symmetric function code for cycle index series

• Conclude OEIS ticket #10358 (rebase after #13701, last doctests, and make urls clickable from the notebook

  ThierryMonteil, Eric, Chris, Salvatore

• More switches from CombinatorialClass to category framework

  Travis, Mike, Anne, Mathieu, Simon, Florent

• Implement LaTeX options for parking functions

  Mike, Jean-Baptiste, Tom D.

• Implement composition tableaux as an enumerated set (finite? with grading?)

  Mike, Chris, Jessica, Austin, Tom D., Elizabeth

• Beef up NSym/QSym functionality - dual bases, quasi-Schur and dual's, basis by Pieri rule, map to free algebra, P-partitions (#14136), Hazewinkel's lambda-Lyndon basis, quasi-Schurs, expansion in non commutative variables, ...

  Mike, Matthieu Deneufchâtel, Darij, Chris, Simon, Anne, Meesue

• Ribbon graphs

  Bruce, Emily, Chris

• Finish affine symmetric group patch (#12940) Done!

  Tom D., Chris, Anne

• Implement BWSym and related Hopf algebras

  Olivier Mallet, Ali Chouria, Jean-Baptiste, Florent, Mike

• Posets - Close outstanding tickets, optimize counting linear extensions, add poset examples (absolute order on symmetric group, etc.)

  Kevin, Nathann, Mathieu, Florent, Anne, Jessica, Tom R., Darij

• Infinite root system: construction, display

  Vivien, Nicolas, Salvatore, William, Elizabeth, Ben, Laura

Representation Theory

• Finalize non-symmetric Macdonald polynomial patch (#14102)

  Anne, Nicolas, Mike

• Implement monomial crystals (#14759) Done and merged!

  Ben, Travis, Arthur, Nicolas, Anne

• Refactor and speedup of all crystals code (#14516 Done!, #14686, more to come)

  Travis, Ben, Nicolas, Anne

• Make progress on fixing/reviewing rigged configurations patches (#13871, #13838, #13872)

  Anne, Travis, Chris

• Representations of quivers and quiver algebras: Finish refactoring Jim's code (#12630)

  Simon, Salvatore, Nicolas, Aladin, Florent, Ben, Tom R., Mathieu

Hyperplane arrangements

Tom, William, Vivien, Nathann, Steven, Alejandro

Categories and infrastructure

Nicolas, Simon, Travis, Florent

• Review #10963 more functorial constructions
• Review #11111 finite dimensional modules
• Nested class name mangling: Understand why building the pdf documentation hangs with the patch from #9107
• Plan the follow ups

Documentation

• Reorganize combinat documentation

  Travis, Nathann, Florent, Mike, Simon, Nicolas, Anne

• Update French translation of the tutorial

  Marc

Teaching

• Going through "Topics in Algebraic Combinatorics" and see how much is in Sage / would be useful for teaching

  Tom^2, Alejandro, Elizabeth, Jessica, Aladin, Austin, Laura

  (Worksheet!)

• Update/fix doctests from the French Sage book

• Marc, Nathann, Nicolas, Guillaume: fix the web version to make sure its 100% consistent with the paper version

• Cleanup Map-Reduce & other parallelization tools in Sage

  Florent, Jean-Baptiste, Matthieu

Other

• Finish CFF #14567 review (ThierryMonteil)

• Trac-ify some of the bugs found via ask.sagemath.org and discuss about better integration between those two useful tools (ThierryMonteil)

• Work on making RIF and CIF more reliable (ThierryMonteil)

• Add parallel cloning to Sage Debian Live USB key (ThierryMonteil)

• FindStat work

  Travis, Viviane, Chris, Jessica, Jean-Baptiste