set positions in butterfly digraph generator

[dcoudert]

We improve the butterfly digraph generator and set the positions of the vertices.

[dcoudert]

on the way, we set position of vertices in method Circuit.

---

New commits:

​04ca0ae

trac #33749: improve butterfly digraph generator

[tscrim]

I don't think we should have this doctest:

sage: digraphs.ButterflyGraph(3).show()  # long time

It doesn't fundamentally do anything for testing. I would have a test that outputs the information you want, the position of the vertices for plotting.

[git]

Branch pushed to git repo; I updated commit sha1. New commits:

​8ebbe46

trac #33749: doctest on position dictionary

[dcoudert]

Let's try this.

[tscrim]

Thanks. LGTM.

[vbraun]

sage -t --long --warn-long 47.0 --random-seed=123 src/sage/graphs/digraph_generators.py
**********************************************************************
File "src/sage/graphs/digraph_generators.py", line 260, in sage.graphs.digraph_generators.DiGraphGenerators.ButterflyGraph
Failed example:
    digraphs.ButterflyGraph(2).get_pos()
Expected:
    {('11', 0): (0, 0),
     ('11', 1): (2, 0),
     ('11', 2): (4, 0),
     ('10', 0): (0, 1),
     ('10', 1): (2, 1),
     ('10', 2): (4, 1),
     ('01', 0): (0, 2),
     ('01', 1): (2, 2),
     ('01', 2): (4, 2),
     ('00', 0): (0, 3),
     ('00', 1): (2, 3),
     ('00', 2): (4, 3)}
Got:
    {('00', 0): (0, 3),
     ('00', 1): (2, 3),
     ('00', 2): (4, 3),
     ('01', 0): (0, 2),
     ('01', 1): (2, 2),
     ('01', 2): (4, 2),
     ('10', 0): (0, 1),
     ('10', 1): (2, 1),
     ('10', 2): (4, 1),
     ('11', 0): (0, 0),
     ('11', 1): (2, 0),
     ('11', 2): (4, 0)}
**********************************************************************
1 item had failures:
   1 of   6 in sage.graphs.digraph_generators.DiGraphGenerators.ButterflyGraph
    [151 tests, 1 failure, 3.19 s]
----------------------------------------------------------------------
sage -t --long --warn-long 47.0 --random-seed=123 src/sage/graphs/digraph_generators.py  # 1 doctest failed
----------------------------------------------------------------------

[git]

Branch pushed to git repo; I updated commit sha1. New commits:

​777fb19	trac #33749: merge with 9.7.beta0
​3efef4c	trac #33740: simpler doctest

[dcoudert]

Let's avoid sorting issues with a simpler test.

[tscrim]

Okay. Although I am slightly surprised that there was an issue but a green patchbot. Usually this is sorted correctly and consistently when running the doctests...

[dcoudert]

I agree this is very surprising. Let's hope we will not hope such issue in other places.