Revision history [back]
 | 1 | initial version |
It is not usual to bundle a database of combinatorial objects coming with Sage by default.
It would be nice to have a (fast) enumerated set of all lattices on a given number of elements. Although my impression is that the set of lattices on a given number of vertices is not easy to generate recursively. Indeed, the lattice property of a poset does not behave well with respect to inclusion, so a recursive enumeration would not work as smoothly as it does for posets.
That said, depending on what you want to do, you could use an iterator:
n_elmt=7
connected_lattice_iterator = (p for p in Posets(n_elmt) if p.is_connected() and p.is_lattice())
to generate all connected lattices one by one.
| | 2 | No.2 Revision |
It is not usual to bundle a database of combinatorial objects coming with Sage by default.
It would be nice to have a (fast) enumerated set of all lattices on a given number of elements. Although my impression is that the set of lattices on a given number of vertices is not easy to generate recursively. Indeed, the lattice property of a poset does not behave well with respect to inclusion, so a recursive enumeration would not work as smoothly as it does for posets.
That said, depending on what you want to do, you could use an iterator:
n_elmt=7
n_elmt = 7
connected_lattice_iterator = (p for p in Posets(n_elmt) if p.is_connected() and p.is_lattice())
to generate all connected lattices one by one.
| | 3 | No.3 Revision |
It is not usual to bundle a database of combinatorial objects coming with Sage by default.
It would be nice to have a (fast) enumerated set of all lattices on a given number of elements. Although my impression is that the set of lattices on a given number of vertices is not easy to generate recursively. Indeed, the lattice property of a poset does not behave well with respect to inclusion, so a recursive enumeration would not work as smoothly as it does for posets.
That said, depending on what you want to do, you could use an iterator:
n_elmt = 7
connected_lattice_iterator = (p for p in Posets(n_elmt) if p.is_connected() and p.is_lattice())
to generate all connected lattices one by one.one, but it does not increase the speed of generation...
