Opened 8 years ago

Closed 7 years ago

# Toroidal6RegularGrid2dGraph

Reported by: Owned by: ncohen jason, ncohen, rlm major sage-5.5 graph theory sage-5.5.rc0 Nathann Cohen David Coudert N/A #13067

Ooch. This patch implements a method with a nasty name. With this one can create 6-regular grids on the torus, and have some acceptable drawing.

It also modifies the embedding of ToroidalGrid2dGraph, as some edges did not appear on the drawing.

Nathann

### comment:1 Changed 8 years ago by ncohen

• Status changed from new to needs_review

### comment:2 Changed 8 years ago by eisermbi

• Status changed from needs_review to needs_info

Hi Nathann,

I looked at the patch and found the modified layout of ToroidalGrid2dGraph better.

For a hexagonal grid graph, can you give some reference with the definition you are using? Your graph is 6-regular while several other definitions are 3-regular. For example, see article 1203.0666v1, section 5, from arXiv.org, or http://mathworld.wolfram.com/HexagonalGrid.html. I am confused ;-)

Birk

### comment:3 Changed 7 years ago by ncohen

• Status changed from needs_info to needs_review

That's rather true... After trying to find an intermediate solution, I ended up renaming the function. It makes more sense like that :-)

I hope that everything is running smoothly on your side ! I am now back from asia and I work in Paris :-)

Nathann

### comment:4 Changed 7 years ago by ncohen

• Description modified (diff)
• Summary changed from ToroidalHexagonalGrid2dGraph to Toroidal6RegularGrid2dGraph

### comment:5 Changed 7 years ago by dcoudert

• Authors set to Nathann Cohen
• Reviewers set to David Coudert
• Status changed from needs_review to needs_work

Hello,

• a space between i and \in (same for j) since otherwise i and in are glued when asking for the doc of the function.
• to write ((i+1)%n_1, (j+1)%n_2 so add ().

But then I found a problem in the method as well as for ToroidalGrid2dGraph, Grid2dGraph, and certainly others: I'm able to call graphs.Toroidal6RegularGrid2dGraph(-1,2) without warnings! O_o

For which values of n1 and n2 are these methods defined? So far, I'm able to produce a graph that is not 6-regular.

David.

### comment:6 Changed 7 years ago by ncohen

• Status changed from needs_work to needs_review

Oh, right. Well, I added what you asked, in this new function and also in Grid2dGraph :-)

Nathann

### comment:7 Changed 7 years ago by dcoudert

• Status changed from needs_review to positive_review

That's much better now.

### comment:8 Changed 7 years ago by ncohen

Thanks ! I'm reimplementing something to compute the girth with static_sparse_graph, because of the conversations on sage-devel these days :-)

It's good to write a piece of code knowing it will not have to be changed later :-)

Nathann

### comment:9 Changed 7 years ago by jdemeyer

• Dependencies changed from 13067 to #13067

### comment:10 Changed 7 years ago by jdemeyer

• Milestone changed from sage-5.4 to sage-5.5

### comment:11 Changed 7 years ago by jdemeyer

• Status changed from positive_review to needs_work

The documentation doesn't build correctly:

/release/merger/sage-5.5.beta2/local/lib/python2.7/site-packages/sage/graphs/graph_generators.py:docstring of sage.graphs.graph_generators.GraphGenerators.Toroidal6RegularGrid2dGraph:16: WARNING: Literal block expected; none found.


and

! Extra }, or forgotten $. l.85529 ...ordinates$(i,j)$for$i \in \{0...i-1}
$? ! Emergency stop. l.85529 ...ordinates$(i,j)$for$i \in \{0...i-1}
$! ==> Fatal error occurred, no output PDF file produced!  ### comment:12 Changed 7 years ago by ncohen • Status changed from needs_work to positive_review Gloops. LaTeX does not like "%" much, and there was a "::" where it should not be. Sorry about that, I just fixed it ! Nathann ### comment:13 Changed 7 years ago by jdemeyer • Status changed from positive_review to needs_work The PDF still doesn't work. ### comment:14 Changed 7 years ago by jdemeyer Are you sure you uploaded the right patch? ### comment:15 Changed 7 years ago by ncohen • Status changed from needs_work to positive_review ~$ md5sum trac_13075.patch /tmp/a.patch
2996688ca9b0d1b325e406f054bdca9a  trac_13075.patch
db9c6e30a366712c2c979dfb6805f94f  /tmp/a.patch


Ahem. Sorry again >_<

Nathann

### comment:16 Changed 7 years ago by jdemeyer

• Merged in set to sage-5.5.rc0
• Resolution set to fixed
• Status changed from positive_review to closed
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