#14099: Adding Method for testing avoidance in posets
------------------------------------------------------+---------------------
Reporter: chrisjamesberg | Owner: rowland
Type: enhancement | Status: new
Priority: minor | Milestone: sage-5.7
Component: combinatorics | Resolution:
Keywords: posets | Work issues:
Report Upstream: N/A | Reviewers: saliola
Authors: chrisjamesberg, rowland, ahmorales | Merged in:
Dependencies: | Stopgaps:
------------------------------------------------------+---------------------
Comment (by rowland):
I don't think subgraph_search answers the same question....
Using induced=True results in the poset Poset({0 : [], 1 : [2], 2 : [3]})
which is 3+1 being (3+1)-free:
{{{
# g is the transitive closure
sage: g = DiGraph({0 : [], 1 : [2, 3], 2 : [3]})
sage: g.subgraph_search(DiGraph({0 : [1], 1 : [2]}) + DiGraph({0 : []}),
induced=True)
}}}
Using induced=False results in the poset Poset({0 : [1, 2], 2 : [3]})
which is (3+1)-free containing (3+1):
{{{
# g is the transitive closure
sage: g = DiGraph({0 : [1, 2, 3], 2 : [3]})
sage: g.subgraph_search(DiGraph({0 : [1], 1 : [2]}) + DiGraph({0 : []}),
induced=False)
Subgraph of (): Digraph on 4 vertices
}}}
--
Ticket URL: <http://trac.sagemath.org/sage_trac/ticket/14099#comment:7>
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.
