Code     

Sage Scripts

Gap3 Scripts

  • print_nc.gap - provides functions to print the cover relations in a noncrossing partition lattice associated with any irreducible well-generated complex reflection group.

Some Lattice Repositories

  • ncp.zip - this is an archive containing a few noncrossing partition lattices. More precisely, the files in this archive contain the cover relations of these lattices. So far, I have included all noncrossing partition lattices associated with:
    • real reflection groups of rank at most 8,
    • irreducible well-generated exceptional non-real complex reflection groups,
    • the groups G(d,d,n) for 3 ≤ d ≤ 8 and 3 ≤ n ≤ 6, as well as 3 ≤ d ≤ 6 and n=7.
  • lattices.zip - this is an archive containing certain families of lattices. So far, I have included all:
    • distributive lattices of size ≤18
    • congruence-uniform lattices of size ≤13
    • extremal lattices of size ≤12
    • left-modular lattices of size ≤12
    • trim lattices of size ≤12
    • join-semidistributive lattices of size ≤12

This archive also contains a script called init.sage that allows for importing these lattices into Sage. Just load said script into Sage, and call the function load_all(type), where the parameter 'type' may be either one of: 'distributive', 'congruence_uniform', 'extremal', left_modular', 'trim', 'join_semidistributive', depending on which class of lattices you want to load. This function returns a dictionary that maps an integer to a list of all lattices of this cardinality. (Of course only if the lattices of the requested type and cardinality are contained in the archive.)