Re: Re: GraphPlot
- To: mathgroup at smc.vnet.net
- Subject: [mg70830] Re: [mg70809] Re: [mg70775] GraphPlot
- From: Carl Woll <carlw at wolfram.com>
- Date: Sat, 28 Oct 2006 23:38:06 -0400 (EDT)
- References: <7490715.316071162046101346.JavaMail.root@vms075.mailsrvcs.net>
Bruce Colletti wrote:
>Carl
>
>In v5.2, why does:
>
> GraphPlot[{...}, VertexStyleFunction -> (Text[#, #] &)
>
>fail when {0,-1} is the Text offset?
>
> GraphPlot[{1 -> 2, 2 -> 3, 3 -> 1, 3 -> 4, 5 -> 6, 6 -> 5},
>VertexStyleFunction -> (Text[#, #,{0,-1}] &)
>
>Thankx.
>
>Bruce
>
>
I don't know the answer, sorry. Apparently there is a problem with the
code that substitutes coordinates for coordinate labels in 3 or 4
argument Text objects.
If you want to draw labels so that they are not obstructed, you could
instead add a couple more graphics directives, e.g.:
GraphPlot[{1 -> 2, 2 -> 3, 3 -> 1, 3 -> 4, 5 -> 6, 6 -> 5},
VertexStyleFunction -> ({Yellow, Disk[#, .2], Black, Circle[#, .2],
Text[#, #]} &)]
Carl Woll
Wolfram Research
>
>
>
>=====================
>From: Carl Woll <carlw at wolfram.com>
To: mathgroup at smc.vnet.net
>Subject: [mg70830] [mg70809] Re: [mg70775] GraphPlot
>
>Matt Curcio wrote:
>
>
>
>>Carl,
>> Thanks for your reply. Sorry I was unclear, let me try to
>>explain better with a simpler example. When you run the code:
>>
>><< DiscreteMath`GraphPlot`;
>>GraphPlot[{1 -> 2, 2 -> 3, 3 -> 1, 3 -> 4, 5 -> 6, 6 -> 5},
>>VertexStyleFunction -> (Text[#, #] &)
>>
>>
>>You see two graphs with the vertices labeled. The rightmost graph is
>>composed of the components {5->6, 6->5}. But the only way I know
>>that is because I've labeled the vertices and my dataset above is so
>>small. What I would like is a function that does the following:
>>
>>MagicalGraphCoordinatesFunction[ {1 -> 2, 2 -> 3, 3 -> 1, 3 -> 4, 5 -
>>
>>
>>>6, 6 -> 5} ];
>>>
>>>
>>which returns:
>>{{1 -> 2, 2 -> 3, 3 -> 1, 3 -> 4}, {5 -> 6, 6 -> 5}}
>>
>>i.e. A list with the elements of the two directed graphs in my data.
>>I am essentially using GraphPlot to discover how many directed graph
>>clusters are in my data. Its great to visualize them, but I would
>>really like to know which elements make up the subgraphs.
>>
>>Thanks again,
>>Matt
>>
>>
>
>Did you try the code I gave in my last post? Trying it out on this
>example, we have:
>
>gr={1 -> 2, 2 -> 3, 3 -> 1, 3 -> 4, 5 -> 6, 6 -> 5}
>
>In[9]:=
>StrongComponents[Join[gr, Reverse /@ gr]]
>Out[9]=
>{{1, 2, 3, 4}, {5, 6}}
>
>This isn't quite what you asked for, but it's close.
>
>Carl Woll
>Wolfram Research
>
>
>
>>
>>On Oct 27, 2006, at 5:13 AM, Carl Woll wrote:
>>
>>
>>
>>>Matt Curcio wrote:
>>>
>>>
>>>
>>>>Hi,
>>>> I have a question about extracting data from the internals of
>>>>GraphPlot. For example, the following code plots multiple
>>>>subplots of disconnected clusters.
>>>>
>>>><< DiscreteMath`GraphPlot`
>>>>n = 129;
>>>>d = Table[i -> Mod[i^2, n], {i, 0, n - 1}];
>>>>GraphPlot[d];
>>>>
>>>>However, I would like to know the subsets that are being plotted.
>>>>I know you can plot the vertex labels on the chart, but my dataset
>>>>is ~50,000 connected vertices and GraphPlot outputs ~100 clusters,
>>>>so vertex labeling is unrealistic. It would be very interesting
>>>>to know which vertices GraphPlot has associated. There maybe a
>>>>way to do this using some functions from "Combninatorica" but I
>>>>have not been able to find them. Can anyone help?
>>>>
>>>>Thanks,
>>>>Matt
>>>>
>>>>
>>>>
>>>I'm not clear on what you want, but have you tried StrongComponents
>>>from the GraphPlot package? This function will give you a list of
>>>the vertices in each disconnected cluster (assuming the graph is
>>>undirected). In your example, we would convert d to an undirected
>>>graph and then use StrongComponents:
>>>
>>>comps = StrongComponents[ Join[d, Reverse/@d] ];
>>>
>>>In[30]:=
>>>Length[comps]
>>>Out[30]=
>>>14
>>>
>>>Carl Woll
>>>
>>>