🚀 go-pugleaf

There is some new and (I'd like to think) interesting code available
by anonymous ftp on lyapunov.ucsd.edu, in the directory pub/inls-ucsd/spider.

Spider is an XView program which does various things: 
	
    * A variant of Thurston's algorithm for computing a postcritically
      finite polynomials from the angles of the external rays landing 
      at the critical point.  For example, enter 1/6 and get out c = i, 
      for the quadratic case (If this makes no sense, nevermind, but 
      notice that the dynamics of 1/6 under multiplication by 2 modulo 1
      has some relationship with the orbit of i under z^2+i). 

    * It draws parameter (Mandelbrot set) and dynamical space (Julia sets)
      pictures using the Koebe 1/4 theorem as in The Science of 
      Fractal Images. This part of the code was largely written by Marc Parmet, 
      but it hasn't really seen the light of day much. This is pretty 
      fast, but I don't really know how fast people draw things these
      days. 

    * It draws external angles on Julia sets. 


If you want to understand the relationship between the Mandelbrot set
and the dynamics of Julia sets, this program is for you. 

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Yuval Fisher                                 e-mail: yfisher@ucsd.edu
Institute for Non-Linear Science 0402                               
University of California, San Diego                                  
La Jolla, CA 92093                                                  
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