Re: [igraph] Cayley Tree

[Marco]

Dear Tamas,

I was convinced, before writing my mail, of what you just wrote, but
looking at the graph I had generated from my code I had to rethink
about it.

Let's suppose that the branching ratio of the tree we want to build is b.
Then, b edges will go from the root node to the first b nodes in the
first generation.
Each of these will have b edges "going out", etc etc 'til the leaves,
which will have a degree one.

This means that each node, aside the root note, will have a degree of
b+1 (b to the next generation and 1 from the previous one); the root
node will have degree b.

So this is a tree, but it's not a k-Cayley tree, since it the root
node doesn't have the same degree as the others node which are not
leaves.

Maybe I am mistaken, and there's some other way to look at it at tune
the Graph.Tree() function to have this kind of tree, but I fail to see
it. :)

Thank you!

marco


--
restituiremo il riso ai salici



On Wed, Nov 18, 2009 at 1:41 PM, Tamas Nepusz <address@hidden> wrote:
> If I understand it right, a k-Cayley tree is simply a tree where each
> non-leaf vertex has degree k. The standard tree generation routine in
> igraph therefore builds a Cayley tree if the number of nodes is set
> appropriately. (See igraph_tree in C, graph.tree in R, Graph.Tree in
> Python).
>
> --
> Tamas
>
> On Wed, Nov 18, 2009 at 12:29:59AM +0100, Marco wrote:
>> Hi all,
>>
>> any ideas on how to implement efficiently a routine to build a Cayley tree?
>>
>> Thanks in advance,
>>
>> marco
>>
>> --
>> restituiremo il riso ai salici
>>
>>
>> _______________________________________________
>> igraph-help mailing list
>> address@hidden
>> http://lists.nongnu.org/mailman/listinfo/igraph-help
>
>
> _______________________________________________
> igraph-help mailing list
> address@hidden
> http://lists.nongnu.org/mailman/listinfo/igraph-help
>