| 1ec681f88b68c6186b267afcce12c7fd667cc9f8 |
|
12-Jul-2006 |
tgdwyer <tgdwyer@users.sourceforge.net> |
Previously graph layout was done using the Kamada-Kawai layout algorithm
implemented in Boost. I am replacing this with a custom implementation of
a constrained stress-majorization algorithm.
The stress-majorization algorithm is more robust and has better convergence
characteristics than Kamada-Kawai, and also simple constraints can be placed
on node position (for example, to enforce downward-pointing edges, non-overlap constraints, or cluster constraints).
Another big advantage is that we no longer need Boost.
I've tested the basic functionality, but I have yet to properly handle
disconnected graphs or to properly scale the resulting layout.
This commit also includes significant refactoring... the quadratic program solver - libvpsc (Variable Placement with Separation Constraints) has been moved to src/libvpsc and the actual graph layout algorithm is in libcola. |