Two more:
- #26284 : deals with comparability.pyx, digraph.py,
vertex_separation.pyx, cutwidth.pyx and connectivity.pyx
- #26285: avoid comparison of vertex labels in MIPs of generic_graph.
Le vendredi 14 septembre 2018 13:43:37 UTC+2, David Coudert a écrit :
>
> I'm working on reducin
I'm working on reducing the number of places where we explicitly compare
vertex labels.
So far I'm focusing on MIPs.
- #26274 : avoid comparison of vertex labels in MIP for file
`graph_coloring.py`
- #26282 : avoid comparison of vertex labels in MIP for file `graph.py`
More to come,
On Thu, Sep 6, 2018 at 11:40 AM David Coudert wrote:
>
> Comparisons like u < v are used in many places in the code of graphs.
> We can try to use hash(u) < hash(v) instead, but this is certainly not the
> smartest solution.
I have a long-outstanding proposal for a SafeSortable utility that
woul
On Thu, 6 Sep 2018, John H Palmieri wrote:
Also not ideal, but you could first try u < v, and if that fails, catch the
error and use str(u) < str(v).
But we can have Graph({'1': [1]}) and so not total order for str() of
vertices.
--
Jori Mäntysalo
On Thursday, September 6, 2018 at 6:23:26 AM UTC-7, David Coudert wrote:
>
> Le jeudi 6 septembre 2018 14:16:33 UTC+2, Martin R a écrit :
>>
>> Would it be hard to separate vertex labels and vertices? In other words,
>> vertices would always be 0,...,n-1, and there would be an additional array
Le jeudi 6 septembre 2018 14:16:33 UTC+2, Martin R a écrit :
>
> Would it be hard to separate vertex labels and vertices? In other words,
> vertices would always be 0,...,n-1, and there would be an additional array
> containing the vertex labels.
>
Some graph backends do that, like `c_graph`. I'
Would it be hard to separate vertex labels and vertices? In other words,
vertices would always be 0,...,n-1, and there would be an additional array
containing the vertex labels.
(I would prefer to have this for many "labelled" combinatorial objects,
such as set partitions, permutations, posets,
Comparisons like u < v are used in many places in the code of graphs.
We can try to use hash(u) < hash(v) instead, but this is certainly not the
smartest solution.
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This also affects various computations in the `homology` directory, since a
common practice is to take a simplicial complex and discard everything
above dimension 1, and then look at the resulting graph. If the vertices in
the original simplicial complex have labels which are not sortable in
Py
