***** To join INSNA, visit http://www.insna.org ***** Thanks everyone for the help (either in this thread or by mail) on drawing trees with defined edge lengths.

We ended up implementing the algorithm in Bachmaier, Brandes and Schlieper (2005), and the result is here:
http://bit.ly/wtz38v 

Its a time series of spanning trees of correlation based distances, where more correlated stocks (vertices) have shorter edges and less correlated ones are further away. Vertex size scales by their Pagerank centrality. It should work on all modern (i.e. not Internet Explorer) browsers.

The functionality is now also available on http://www.fna.fi (free web service) for anyone needing such.

Best,
Kimmo

2012/3/3 David Krackhardt <[log in to unmask]>
Kimmo,

Too bad you're not interested in the height of the tree.  All you'd
have to do is generate the tree at the University of Michigan.  I've
heard that they're all the right height there.  -David

2012/3/2 Kimmo Soramäki <[log in to unmask]>:
> ***** To join INSNA, visit http://www.insna.org ***** Thanks Moses
>
> I was thinking Minimum Spanning Trees (of any graph) and ability to define
> the (visual) length of each edge separately in a layout (I did not mean
> height of the tree).
>
> Meanwhile I found
> http://www.inf.uni-konstanz.de/algo/publications/bbs-dpt-05.pdf (Bachmaier,
> Brandes and Schlieper) which looked promising (radial layout pseudocode).
>
> I'll post the results of implementing the above.
>
> Best,
> Kimmo
>
> 2012/3/2 Moses Boudourides <[log in to unmask]>
>>
>> Hi,
>>
>> What exactly do you mean by "length of the edges"? Is this the same
>> with the level of nodes in a rooted tree, the maximum of which being
>> what is called the height of the tree?
>>
>> If yes, then in the case of a binary tree T with n nodes, you may want
>> to consider that the height of a tree ht(T) is bounded by
>>
>> ceiling(lg(n + 1) - 1) \leq ht(T) \leq (n - 1)/2,
>>
>> where lg is the logarithm with base 2.
>>
>> Furthermore, among all regular binary trees with n nodes, the minimum
>> average level for the leaves is attained by the complete regular
>> binary trees.
>>
>> Now, a good source of algorithms  on search trees is Robert Tarjan's
>> Data Structures and Network Algorithms (chapter 4 etc.).
>>
>> I understand that these hints might not be what you're looking for (in
>> case you may wish to remain on visualization techniques). Perhaps
>> others in the list might be able to help you more on this.
>>
>> Best,
>>
>> --Moses
>>
>>
>> 2012/3/2 Kimmo Soramäki <[log in to unmask]>:
>> > ***** To join INSNA, visit http://www.insna.org ***** Hello everyone
>> >
>> > Does anyone know of an algorithm (any language) for drawing a tree graph
>> > with the constraint that the length of the edges is pre-specified? If
>> > the
>> > algorithm is in Java and specifies vertex coordinates - even better.
>> >
>> > Most algorithms I see adjust the length of the edges for visual
>> > purposes.
>> >
>> > Thanks a lot!
>> >
>> > Kimmo
>> >
>> > -------------------------------
>> > Kimmo Soramaki
>> > Founder, www.fna.fi
>> > Blog, www.fna.fi/blog
>> > [log in to unmask]
>> > +34-662-594-200
>> > _____________________________________________________________________
>> > SOCNET
>> > is a service of INSNA, the professional association for social network
>> > researchers (http://www.insna.org). To unsubscribe, send an email
>> > message to
>> > [log in to unmask] containing the line UNSUBSCRIBE SOCNET in the
>> > body of
>> > the message.
>
>
>
>
> --
> -------------------------------
> Kimmo Soramaki
> Founder, www.fna.fi
> Blog, www.fna.fi/blog
> [log in to unmask]
> +34-662-594-200
> _____________________________________________________________________ SOCNET
> is a service of INSNA, the professional association for social network
> researchers (http://www.insna.org). To unsubscribe, send an email message to
> [log in to unmask] containing the line UNSUBSCRIBE SOCNET in the body of
> the message.



--
 --------------------

David Krackhardt, Professor of Organizations, Executive Editor of JoSS
Heinz College of Public Policy and Management, and
     The Tepper School of Business
Carnegie Mellon University
Pittsburgh, PA 15213
412-268-4758
website: www.andrew.cmu.edu/~krack
     (Erdos#=2)

--------------------



--
-------------------------------
Kimmo Soramaki
Founder, www.fna.fi
Blog, www.fna.fi/blog
[log in to unmask]
+34-662-594-200
_____________________________________________________________________ SOCNET is a service of INSNA, the professional association for social network researchers (http://www.insna.org). To unsubscribe, send an email message to [log in to unmask] containing the line UNSUBSCRIBE SOCNET in the body of the message.