# Re: dual graph

From: Dmitry A. Kazakov <mailbox_at_dmitry-kazakov.de>

Date: Tue, 27 Jun 2006 09:16:14 +0200

Message-ID: <7fngvin8f2no.wbi23fndg7aq$.dlg_at_40tude.net>

> Of course I can order the set of nodes. I just start somewhere, and

Date: Tue, 27 Jun 2006 09:16:14 +0200

Message-ID: <7fngvin8f2no.wbi23fndg7aq$.dlg_at_40tude.net>

On Mon, 26 Jun 2006 13:33:51 -0600, Chris Smith wrote:

> You've really lost me now. The question was what to call a graph whose

*> dual has only one node (i.e., the edges don't divide the plane). The
**> correct answer is "forest" (or "tree", if we assume connectedness).
**> "Ordered" is decidedly not a correct answer.
*

OK, I thought the question was about hierarchies. My mistake.

>>> Any graph >>> (planar or not, cycles or not, doesn't matter) may be made into an >>> ordered graph simply by defining an order for its nodes. >> >> If you can order the set of nodes. But that order is not necessary G*.

*>*> Of course I can order the set of nodes. I just start somewhere, and

*> start counting, like so... 1, 2, 3, 4, and so on.**> Who cares if the**> order I come up with is equivalent to the transitive closure of a**> directed graph?*The hierarchy does.

-- Regards, Dmitry A. Kazakov http://www.dmitry-kazakov.deReceived on Tue Jun 27 2006 - 09:16:14 CEST