View source for Misc. Prefuse Information

These notes are taken from the javadocs provided with Prefuse, and most of them are authored by Jeffrey Heer.  The full index for the Prefuse package can be found [http://prefuse.org/doc/api/index-files/index-1.html here].

=The Force Field=

Force function which computes an n-body force such as gravity, anti-gravity, or the results of electric charges. This function implements the the Barnes-Hut algorithm for efficient n-body force simulations, using a quad-tree with aggregated mass values to compute the n-body force in O(N log N) time, where N is the number of ForceItems.

The algorithm used is that of J. Barnes and P. Hut, in their research paper A Hierarchical O(n log n) force calculation algorithm, Nature, v.324, December 1986. For more details on the algorithm, see one of the following links --

* [http://www.cs.berkeley.edu/~demmel/cs267/lecture26/lecture26.html James Demmel's UC Berkeley lecture notes]
* [http://www.physics.gmu.edu/~large/lr_forces/desc/bh/bhdesc.html Description of the Barnes-Hut algorithm]
* [http://www.ifa.hawaii.edu/~barnes/treecode/treeguide.html Joshua Barnes' recent implementation]