2007/4/29, Anton Sherwood <anton.sherwood@gmail.com>:

> Anton Sherwood wrote:

> > I'm using eigenvectors of a graph's adjacency matrix as "topological"

> > coordinates of the graph's vertices as embedded in 3space (something I

> > learned about just recently). Whenever I've done this with a graph that

> > *does* have a good 3d embedding, using the first eigenvector results in

> > a flat model: apparently the first is not independent, at least in such

> > cases. . . .

Charles R Harris wrote:

> . . . the embedding part sounds interesting,

> I'll have to think about why that works.

It's a mystery to me: I never did study enough matrix algebra to get a

feel for eigenvectors (indeed this is the first time I've had anything

to do with them).

I'll happily share my code with anyone who wants to experiment with it.

Seems to me that this is much like Isomap and class multidimensional scaling, no ?

Matthieu