{{{#!rst Sage Days 40 Coding Sprint Projects =================================== **For the main Sage Days 40 wiki page go** `here`__. __ http://www.ima.umn.edu/2011-2012/SW7.9-13.12/ Below is a list of proposed projects. Symmetric functions and Hopf algebras ===================================== Refactoring and extensions to symmetric functions / KSchur ---------------------------------------------------------- Anne Schilling, Mike Zabrocki, Dorota See also the review of Stembridge's packages below Arithmetic dynamics & symmetric functions ----------------------------------------- Ben Hutz Refactoring and extensions to Hopf algebras ------------------------------------------- Anne Schilling, Mike Zabrocki, John, Franco Graded Algebras --------------- Franco, John Hopf algebras on graphs ----------------------- Jeremy NCSF/QSYM --------- Chris, Mike, Holly, Dorota, Franco, Nicolas? Partition algebras and their reps --------------------------------- George Quiver representations ====================== Gregg Musiker, Peter Webb, Franco Saliola, Charles Paquette, Alex Fink, Julie, Al Garver, Emily Gunawan User stories__: __ attachment:quiver_representations.sage Clusters algebras from surfaces =============================== Gregg Musiker, Al Garver, Weiwen Gu, Emily Gunawan Combinatorics ============= Alternating sign matrices ------------------------- Jessica Striker Graphs ------ Status as of Wednesday: Jeremy wrote some code to contract edges, check whether an edge is a cut-edge, and compute the Tutte polynomial. Lauren and Matt are beta-testing it. (It also needs commenting, examples, etc.) Could you please poset the trac ticket number here? I am very interested to see your work (Anne). Jeremy L. Martin, Anne Schilling, Tom, Lauren - Tutte Polynomial Kevin, Thomas Review of what's missing from Stembridge's packages --------------------------------------------------- Alex, Drew, Thomas, Kevin Posets & Simplicial complexes ----------------------------- Demo including facade posets: Kim Vic Jessica Striker, Jeremy, John^2, Charles?, Kevin, Thomas, Alex Csar? Wish List: * is_modular - Alex Csar * is_atomic - Alex Csar * is_semimodular - Alex Csar - adding functionality to poset elements--what does this mean? - iterate over lattices - zeta, order, characteristic polynomials * characteristic polynomial done naively * zeta polynomial from Stembridge's posets code * W polynomial coming--relabel the poset and then look at permutations - more examples of posets * Young diagrams - Kevin * Semistandard tableaux - Jessica/Julie * interval posets - graph_editor - disjoint union, ordinal sum, product - make dual poset function work properly for lattices (it seems to break the join) Simplicial Complexes: --------------------- Shellability G-posets - homology modules H_*(-, R), H^*(-, R) when R is neither **Z** nor a field cup products `trac #6102 `_ cohomology operations how to represent (co-)homology classes? `trac #6100 `_ links (already done) stars Cohen-Macaulay (`trac #11523 `_, needs review) Fundamental Group (should not be too hard, using the code from `trac #12339 `_) is_shifted is_pseudo-manifold (`trac #13226 `_, needs review) triangulate complex projective space (research problem; see `mathoverflow `_) chain complexes: - fix bug for map induced by map of simplicial complexes: see `trac #13220 `_, positive review. - induced map on homology (high priority) `trac #6101 `_ - mapping cone - tensor product - Tot of a bicomplex - filtered chain complexes and the associated spectral sequence? Topological structures & categories & their reps ------------------------------------------------ Peter Webb, John Coxeter groups, Hecke algebras, Crystals, ... ============================================= Crystals -------- (`trac #12251 `_, positive review) Anne Schilling, Mark Shimozono, Julie, Dan Bump, Ben Brubaker, Arthur Lubovsky Extended Affine hecke algebras / weyl groups -------------------------------------------- Non symmetric Macdonald polynomials & friends in general types Mark, Nicolas, Anne, Dan, Ben, Daniel Integration of (affine) symmetric group and Coxeter groups ---------------------------------------------------------- Alex Csar, Tom Denton, Holly Complex reflexion groups ------------------------ Alex Miller Schubert Calculus ----------------- Mark, Alex, Nicolas, Kaisa, Yasuhide, Tom Grothendieck polynomials / ... ------------------------------ Kaisa / Nicolas; checking out with Viviane's code Mark Shimozono, Jessica Striker Statistics on permutations -------------------------- Kim2 Matroids -------- Jeremy, Vic I learned that there is a matroid project well underway already: see `trac #7477 `_ and/or the Google group `sage-matroid `_. -- Jeremy Sage Documentation ================== John: - build the documentation in parallel (`trac #6495 `_) needs review - use MathJax by default when building the documentation (`trac #13143 `_) needs review Sagetex ------- Nicolas, Dan Misc ==== Get my patches into Sage ------------------------ Nicolas, Franco, Dan, Gregg Anne (`trac #12251 `_, positive review), (`trac #13224 `_, positive review) (`trac #13222 `_, positive review) Interface to Gfan and version update ==================================== Marshall Hampton }}} {{http://garsia.math.yorku.ca/~zabrocki/pics/sagedays40.jpg}}