#8330: BipartiteGraph needs to hook delete_vertex() and delete_vertices()
----------------------------+-----------------------------------------------
Reporter: rhinton | Owner: rhinton
Type: defect | Status: needs_work
Priority: major | Milestone: sage-4.3.4
Component: graph theory | Keywords: BipartiteGraph
Author: Ryan Hinton | Upstream: N/A
Reviewer: | Merged:
Work_issues: |
----------------------------+-----------------------------------------------
Changes (by rhinton):
* status: needs_review => needs_work
Old description:
> !BipartiteGraph needs to hook delete_vertex() and delete_vertices().
>
> {{{
> }}}
>
> It should also hook the add_vertex() and add_edge() (and similar) calls,
> but not sure of the right way to do this.
New description:
!BipartiteGraph needs to hook delete_vertex() and delete_vertices().
{{{
sage: g = BipartiteGraph(graphs.CycleGraph(4))
sage: (g.left, g.right)
([0, 2], [1, 3])
sage: g.delete_vertex(0)
sage: g.left
[0, 2]
}}}
Note vertex 0 still shows up in the left partition.
It should also hook the add_vertex() and add_edge() (and similar) calls,
but not sure of the right way to do this.
--
Comment:
I just tested graph.py for another potential change, and found that a few
doctests fail due to this patch. Specifically, the tests create
BipartiteGraphs (e.g. K23), and the Graph algorithm adds a temp vertex,
then deletes it later. But the new delete_vertex() raises an exception
when it can't find the temp vertex in its left or right sets.
So we may need to fix add_vertex before this delete_vertex solution will
work. Or should we do a soft-fail (print a warning?) instead of raising
an exception?
--
Ticket URL: <http://trac.sagemath.org/sage_trac/ticket/8330#comment:4>
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 post to this group, send email to [email protected].
To unsubscribe from this group, send email to
[email protected].
For more options, visit this group at
http://groups.google.com/group/sage-trac?hl=en.
