Is it possible to represent associations as directed edges in Vizigator or Vizdesktop

[Dickinson]

Dear users,

I want to represent a topic map as a directed graph, with associations
between the instances, represented as directed edges. However, I
cannot find how to do that. Additionally, I thought of the idea,
making the colour of the edge white (so it cannot be seen) and stick
an icon, but the icon representing the edge is showing only one
direction and is not "sticky" to the edge. Any help would be
appreciated.

Best Regards,
Ivan

[Murray Altheim]

Quoting Dickinson <ipep...@googlemail.com>:

Hi Ivan,

Another option is something called a bipartite graph, where the edges
carry no semantics, with both Topics and Associations displayed as
their own node types.

Back in about 2000 I began work on a project that lasted for much of
a decade, called Ceryle. It uses a highly customised version of the
TouchGraph java package and represents Topics and Associations with
small rectangles, connected by rubber-banded edges that themselves
carry no semantics. Edges were built by drawing a series of lines
from multiple points to a single point, effectively making a long
thin triangle to show direction. The midpoint of those lines is
easy to locate, so you could hang your icon off that point if you
wished.

TG's author, Alexander Shapiro, has since commercialised the code and
doesn't distribute it, but I believe the original TouchGraph package
may still be around on the internet somewhere. It was itself based on
an early Java code example showing a rubber-banded graph.

Hope that is of some help.

Murray

http://en.wikipedia.org/wiki/Bipartite_graph
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