readme.1st

分形维数的估算软件FD3

			Synopsis of FD3
 
FD3 is a program that estimates fractal dimension.

It was written by John Sarraille and Peter DiFalco, using ideas
from "A FAST ALGORITHM TO DETERMINE FRACTAL DIMENSION BY BOX
COUNTING", by Liebovitch and Toth, Physics Letters A, 141,
386-390 (1989).

FD3 inputs an ascii list of points, basically one point per
line, and outputs box counts at various scales, plus estimates
of capacity, information, and correlation dimension.

There are "two-point" estimates of dimension for each scale
shift (division of cell size by two), plus overall estimates
based on fitting a least-squares line to a log-log plot of cell
count versus cell size.

FD3 is quite accurate (typically well within 5% when tested on
reasonably-sized samples of fractals whose dimension are known
exactly)

It is quite fast -- O(NlogN) where N is the number of data lines
(points) input.  

In theory, it will handle any embedding dimension -- points
with one coordinate each, two coordinates each, three, four,
... whatever.  However, the number of points needed for usable
results increases geometrically with the dimension of the set.

For more information on how to use FD3, see the files INDEX,
README.2, and REPORT.INF


/* BEGIN NOTICE

Copyright (c) 1992 by John Sarraille and Peter DiFalco
([e-mail])

Permission to use, copy, modify, and distribute this software
and its documentation for any purpose and without fee is hereby
granted, provided that the above copyright notice appear in all
copies and that both that copyright notice and this permission
notice appear in supporting documentation.

The algorithm used in this program was inspired by the paper
entitled "A Fast Algorithm To Determine Fractal Dimensions By
Box Counting", which was written by Liebovitch and Toth, and
which appeared in the journal "Physics Letters A", volume 141,
pp 386-390, (1989).

This program is not warranteed: use at your own risk.

END NOTICE */