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Path: utzoo!utgpu!watserv1!watmath!att!cbnewsh!wcs
From: wcs@cbnewsh.ATT.COM (Bill Stewart 201-949-0705 erebus.att.com!wcs)
Newsgroups: sci.math.num-analysis,sci.math,comp.graphics,comp.terminals.tty5620,comp.theory
Subject: How much precision does Mandelbrot need
Message-ID: <8602@cbnewsh.ATT.COM>
Date: 2 Mar 90 19:44:23 GMT
Reply-To: wcs@cbnewsh.ATT.COM (Bill Stewart 201-949-0705 erebus.att.com!wcs)
Organization: Bell Labs Random Organization Name Generator
Lines: 21

How much precision does it take to calculate Mandelbrot sets correctly?
Do I need to use infinite-precision fractions, or is
single-precision or double-precision floating point enough?
Is it worth doing fixed-point with scaled integers, since the
numbers never get very big?  Since Mandelbrot sets depend very
strongly on initial conditions, it would seem that loss of precision
would quasi-randomly cause different results near any boundaries.
Is this the case?

The choices I have for computing equipment are basically an 8-MIPS
3B2 with decent IEEE floating point, or to use my AT&T 630 terminal
(<1 MIPS 68010, but its CPU isn't all that busy most of the time.)
If I really need DP, I'll do it down on the 3B, but it would be a
nice hack to have a Mandelbrot tool in my terminal.

			Thanks;  Bill
-- 
# Bill Stewart AT&T Bell Labs 4M312 Holmdel NJ 201-949-0705 erebus.att.com!wcs
# Fax 949-4876.  Sometimes found at Somerset 201-271-4712
# He put on the goggles, waved his data glove, and walked off into cyberspace.
# Wasn't seen again for days.