Graphs: grouped sporadic distance-regular graphs in a function

[Ivo-Maffei]

Added a function distance_regular_graph with the purpose to build distance-regular graphs given their intersection array. At the moment we grouped only the sporadic constructions and serious existence checks are only done via the external package https://github.com/jaanos/sage-drg.

Depends on #30355
Depends on #30343

CC: @dimpase

Component: graph theory

Author: Ivo Maffei

Branch/Commit: 0a9a194

Reviewer: Dima Pasechnik

Issue created by migration from https://trac.sagemath.org/ticket/30356

[Ivo-Maffei]

Branch: public/graphs/30356

[Ivo-Maffei]

comment:1

I will add more constructions to this function later on.
Now I'm mainly concerned with how to handle the drg package.

---

Last 10 new commits:

35a457e	Merge branch 30337 into 30343
d0ca365	Merge branch 'drg_gen_pol' into drg_general_func
0268857	fixed most sporadic graphs; added some docstring; added method to graphs
51dda87	added (extended) bipartite double method to undirected graphs
eed2fe3	fix bug with extended bipartite
0f2dcce	added more doctests
13dc48a	Merge branch 30240 into bipartite_double
864cd35	Merge branch 'bipartite_double' into drg_general_func
17a0b90	completed sporadic database; added more docstrings; added basic checks
bd5ef0a	fixed docstring and doctests

[Ivo-Maffei]

Commit: bd5ef0a

[Ivo-Maffei]

Changed dependencies from #300355 to #30355

[sagetrac-git]

Changed commit from bd5ef0a to 1a143bc

[sagetrac-git]

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

2d6c8ba	fix docstring; added doctests; simplier code
1a143bc	Merge branch #30355 into #30356

[dimpase]

Reviewer: Dima Pasechnik

[dimpase]

comment:3

after merging beta9 in, doctests fail, e.g.

File "src/sage/graphs/generators/distance_regular.pyx", line 15, in sage.graphs.generators.distance_regular
Failed example:
    H = graphs.distance_regular_graph([15, 14, 10, 3, 1, 5, 12, 15])
Exception raised:
    Traceback (most recent call last):
      File "/mnt/opt/Sage/sage-dev/local/lib/python3.7/site-packages/sage/doctest/forker.py", line 715, in _run
        self.compile_and_execute(example, compiler, test.globs)
      File "/mnt/opt/Sage/sage-dev/local/lib/python3.7/site-packages/sage/doctest/forker.py", line 1139, in compile_and_execute
        exec(compiled, globs)
      File "<doctest sage.graphs.generators.distance_regular[2]>", line 1, in <module>
        H = graphs.distance_regular_graph([Integer(15), Integer(14), Integer(10), Integer(3), Integer(1), Integer(5), Integer(12), Integer(15)])
      File "sage/graphs/generators/distance_regular.pyx", line 1902, in sage.graphs.generators.distance_regular.distance_regular_graph (build/cythonized/sage/graphs/generators/distance_regular.c:25204)
        any([(arr[d+i+1] - arr[d+i]) < 0 for i in range(d)]):
    IndexError: list index out of range

[sagetrac-git]

Changed commit from 1a143bc to 085d36e

[sagetrac-git]

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

4d91c20	Merge branch 9.2.beta9 into 30356
085d36e	fixed existence checks without drg module

[Ivo-Maffei]

comment:5

I forgot to test the code without the drg module. Now it should be fixed.

[dimpase]

comment:6

this ticket also gets shot down by dog-slow and memory-hungry sage.graphs.generators.distance_regular.HermitianFormsGraph

[Ivo-Maffei]

Changed dependencies from #30355 to #30355, #30343

[sagetrac-git]

Branch pushed to git repo; I updated commit sha1. Last 10 new commits:

a0463d5	fix docsrtings; renamed module
5d16394	renamed in design_catalog
e6ff3fa	Merge branch 't/30223' into t/30337
3e1df8c	added const to half cube
0d92ec4	Merge branch 't/30329' into t/30337
ac3ed1a	Merge branch 't/30337' into t/30343
376d459	convert matrices in bilinearFormsGraph to integers to lower memory requirements
11d9953	Merge branch 't/30337' into t/30343
5367858	some code formatting
fd258e8	Merge branch 't/30343' into t/30356

[sagetrac-git]

Changed commit from 085d36e to fd258e8

[sagetrac-git]

Changed commit from fd258e8 to 625b266

[sagetrac-git]

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

625b266

added doctests to _integersection_array_from_graph

[dimpase]

comment:10

should this be rebased over the latests positively reviewed tickets by you?

[Ivo-Maffei]

comment:11

Replying to @dimpase:

should this be rebased over the latests positively reviewed tickets by you?

Yes. The dependency chain is #30312 -> #30329 -> #30337 -> #30343 -> #30356
At the moment #30312 and #30329 are done. When #30343 will be sorted (rebased on updated #30337), I'll fix this ticket as well

[fchapoton]

comment:12

It seems to be a not-so-good idea to have such long chains of dependencies, if not really required. This can be blocked at any step. Think parallel instead of series.

[dimpase]

comment:13

without refactoring into smaller modules, this looks hard to avoid.

[fchapoton]

comment:14

Indeed. This was just a non-specific comment.

Note that one of the patchbot plugins is not green.

[sagetrac-git]

Branch pushed to git repo; I updated commit sha1. Last 10 new commits:

1fdcad9	fixed typo
c97bda5	Merge branch 't/30329' into t/30337
3024980	faster implementation of HalfCube
898fbee	added positions to HalfCube
d9c9149	Merge branch 't/30509' into t/30337
3449361	Merge branch 9.2.beta12 into t/30337
b99474b	Merge branch 't/30337' into t/30343
7d17b7d	removed blank lines
717cf19	Merge branch 't/30343' into t/30356
63c88c0	fix bug; avoid long computations on import

[sagetrac-git]

Changed commit from 625b266 to 63c88c0

[Ivo-Maffei]

comment:16

Merged all dependencies and fixed a bug

[dimpase]

comment:17

OK

[sagetrac-git]

Branch pushed to git repo; I updated commit sha1 and set ticket back to needs_review. This was a forced push. Last 10 new commits:

47b0aba	remote extra spaces
ad0c3bb	typo in the graph name string
a176e0b	missing #optional tag added
54499c7	sketch general function with conditionals for drg module
c5f0f3d	fixed most sporadic graphs; added some docstring; added method to graphs
f675f2c	completed sporadic database; added more docstrings; added basic checks
e4b1d59	fixed docstring and doctests
9aa7d07	fixed existence checks without drg module
4bba926	added doctests to _integersection_array_from_graph
3b61736	fix bug; avoid long computations on import

[sagetrac-git]

Changed commit from 63c88c0 to 3b61736

[dimpase]

comment:20

rebased over #30343

[sagetrac-git]

Branch pushed to git repo; I updated commit sha1. This was a forced push. New commits:

0a9a194

fix bug; avoid long computations on import - typo fixed

[sagetrac-git]

Changed commit from 3b61736 to 0a9a194

[vbraun]

Changed branch from public/graphs/30356 to 0a9a194