Oscar,
> I am not a visad expert, but I recommend not coupling the graph (adjacency
> matrix or adjacency list) data structure to the existing VisAD data
> structures, until it comes time for the embedding in R^2 or R^3 (which is
> the function performed by the layout algorithm). It will be easier for
> people to import graph data into whatever you design if you keep the
> topology encoding and the cartesian embedding conceptually orthogonal to
> each other.
Yes, that's exactly what I am after. I am especially interested in the
combination of multiple layout algorithms in one graph, but I do not have
experience with that yet.
Possibly this could be achieved by defining a strength or weight for each
layout-algorithm at runtime, so that a higher-weight algorithm overrides the
lower ones.
This approach is used in the cassowary constraint solver - it also uses the
metaphor of suggestion: The user (or a layout mechanism ) can *suggest* new
positions for nodes of the graph, but cannot assume that the changes make it
thru (for example, if the new position of the node would conflict with a
constraint or another layout mechanism.)
Manuel
