hi chris,

I think your problem is that all your verticies are at the same location.

...

From the documentation:

" Prior to invoking this algorithm, it is recommended that the vertices be placed along the vertices of a regular n-sided polygon via circle_layouthttp://www.boost.org/libs/graph/doc/circle_layout.html. "

thank you so much, that was it. i actually read the docs, but since it says "recommended" i thought i'd rather leave it away to make things not even more complicated. i think i will suggest to have the documentation changed to "...it is required that...". lots of regards, sebastian mecklenburg