#14267: alternative algorithm for the lattice of order ideals of a poset
-----------------------------+----------------------------------------------
Reporter: chapoton | Owner: tbd
Type: enhancement | Status: new
Priority: minor | Milestone: sage-5.9
Component: PLEASE CHANGE | Keywords: poset
Work issues: | Report Upstream: N/A
Reviewers: | Authors:
Merged in: | Dependencies:
Stopgaps: |
-----------------------------+----------------------------------------------
I propose to implement another algorithm, which seems to be slightly
faster than the existing implementation, at the cost of being defined on
antichains instead of order ideals.
{{{
sage: P = Posets.ChainPoset(5)
sage: Q = P.product(P)
sage: Q.order_ideals_lattice()
Finite lattice containing 252 elements
sage: new_J(Q)
Finite lattice containing 252 elements
sage: new_J(Q).is_isomorphic(Q.order_ideals_lattice())
True
sage: timeit('Q.order_ideals_lattice()')
5 loops, best of 3: 5.25 s per loop
sage: timeit('new_J(Q)')
5 loops, best of 3: 3.45 s per loop
}}}
--
Ticket URL: <http://trac.sagemath.org/sage_trac/ticket/14267>
Sage <http://www.sagemath.org>
Sage: Creating a Viable Open Source Alternative to Magma, Maple, Mathematica,
and MATLAB
--
You received this message because you are subscribed to the Google Groups
"sage-trac" group.
To unsubscribe from this group and stop receiving emails from it, send an email
to [email protected].
To post to this group, send email to [email protected].
Visit this group at http://groups.google.com/group/sage-trac?hl=en.
For more options, visit https://groups.google.com/groups/opt_out.
