
	DLA Version 1.2 - July 1999

	Diffusion Limited Aggregation

Type "cd src; make" to install.

Type "cd examples; ex.run" to see an example.

The program dla draws the results of aggregation using
conformal mappings.  It tracks the growth of
the size of the aggregate, measured by its
transfinite diameter, and also writes a postscript
file showing the aggregate and images of circles
under the Riemann mapping to the outside.

The aggregate starts with the unit disk; thereafter
it is augmented by "buds" consisting of hyperbolic
halfplanes, in the Poincare metric on the complement
of the aggregate.  The halfplane is chosen at
random with respect to harmonic measure, and the
Euclidean distance between the endpoints of its
bounding geodesic is a fixed constant "s".

Type dla -help to get a list of options.

Examples:
dla > x.ps
	Draws a 10 generation aggregate, and puts
	the result in the postscript file "x.ps".
	The default value of s makes the first
	bud the same size as the unit disk.
	A table giving the transfinite diameter of the
	aggregate at each generation is written to 
	the file "caps.data".

dla -g 20 -s 0.1 -c 5 -r 2.0 -f x.data > x.ps
	Draws a 20 generation aggregate with buds
	of size 0.1, putting 5 curves in the
	picture representing the images of the
	Riemann mapping of circles of radius between
	1.0 and 2.0.  Writes the transfinite
	diameter table to "x.data".

dla -g 1000 -f x.data -o
	Writes the table of diameters for 1000
	generations to x.data; omits writing the
	postscript file.

dla -S 0 > x.ps
	The -S option fixes the random seed; 
	this command, unlike those above, draws the same
	picture every run.

Copyright (c) March 1996, July 1999

Curtis T McMullen

email: ctm@math.berkeley.edu
