[with patch, positive review] graph multiedge plotting

[ekirkman]

Wanted: New code to make a pretty plot of graphs with multiedges. I'm working on a patch now and will post it soon.

[mhansen]

Awesome!

[robertwb]

Some code from Ashley Saunders up at  http://wiki.wstein.org/2008/480a/theprojects

[rlm]

This depends on #4774, and implements multiple edges for graphs only.

[rlm]

This set of patches should fix #5248.

[rlm]

This is still a little quirky, due to issues with #4774, but it will be great to get this merged. The only problems left are on a different ticket.

+ exp[(10!)^(10!)]

[rlm]

Apply both patches in order.

[mabshoff]

This is going into 3.3.

Cheers,

Michael

[ekirkman]

Just fixes edge_color and adds a doctest

[ekirkman]

I caught some things while looking at the plots. It should be a pretty quick review-- hopefully I got it in fast enough.

[mabshoff]

What is the credit situation here? I assume Emily as author, Robert for review?

Cheers,

Michael

[mabshoff]

There is one doctest failure:

mabshoff@sage:/scratch/mabshoff/sage-3.3.rc1$ ./sage -t -long devel/sage/sage/combinat/crystals/crystals.py
sage -t -long "devel/sage/sage/combinat/crystals/crystals.py"
**********************************************************************
File "/scratch/mabshoff/sage-3.3.rc1/devel/sage/sage/combinat/crystals/crystals.py", line 553:
    sage: C.plot()
Expected:
    Graphics object consisting of 11 graphics primitives
Got:
    Graphics object consisting of 17 graphics primitives
**********************************************************************

I assume this is becase previously the graph was incorrect.

Cheers,

Michael

[mabshoff]

After checking with Mike Hansen he gave me the thumbs up for the change, so I will post a tiny reviewer patch in a second. Note that trac_3541_tinyfixes.patch is a diff, but I committed in Emily's name :)

Cheers,

Michael

[mabshoff]

Merged

• trac_3541-multiedge-1.patch
• trac_3541_beezy.patch
• trac_3541_tinyfixes.patch
• trac_3541-reviewer-doctest.patch

in Sage 3.3.rc1. :)

Cheers,

Michael

[rlm]

Emily wrote all that by herself. I only reviewed and helped her with matplotlib.

[mvngu]

sample plot of a multi-edge graph

[mvngu]

Uploaded an image of a sample plot of a multi-edge graph. The graph was produced using the following code from the docstring of sage.graphs.graph.GenericGraph.plot:

sage: g = Graph({}, loops=True, multiedges=True)
sage: g.add_edges([(0,0,'a'),(0,0,'b'),(0,1,'c'),(0,1,'d'), 
...     (0,1,'e'),(0,1,'f'),(0,1,'f'),(2,1,'g'),(2,2,'h')]) 
sage: g.plot(edge_labels=True, color_by_label=True, edge_style='dashed')

I uploaded the image here, so it can be referred to in the release tour of 3.3.