[comp.sources.wanted] Greengard algorithm wanted

peb@tma1.Sun.COM (Paul Baclaski) (09/08/89)

I recently ran across a book entitled "The Rapid Evaluation of 
Potentials in Particle Fields" by Dr. Greengard (MIT Press, 1988)
which describes an algorithm that calculates the n-body problem 
with respect to gravitational or electrostatic fields such that 
the complexity is O(n) rather than O(n^2).  It appears to use
quadtrees and fields.
 
I would think that if this is possible, source code would be 
available to do this...or at least an understandable description
of the algorithm (the book is rather dry).
  
Please send me pointers to better descriptions, third party 
analysis or best of all *shareware*/*public domain* software
that implements the Greengard algorithm.  (If you have Greengard's
email address...)
   
Please send me mail directly since I don't read this newsgroup.
    
Thanks in advance,
     
      
Paul E. Baclaski
Sun Microsystems
peb@sun.com