🚀 go-pugleaf

RetroBBS NetNews Server

Inspired by RockSolid Light RIP Retro Guy

Article View: sci.fractals
Article #160

Re: Mappings with singular points

#160
From: Ken Shirriff
Date: Mon, 09 Nov 1992 00:31
28 lines
1605 bytes
In article <1992Nov8.234155.14813@mnemosyne.cs.du.edu> ddixon@nyx.cs.du.edu (David Dixon) writes:
>Is anybody aware of any differences between mappings with and without
>singular points?  For example, say I have a map x[n+1] = f(x[n]), where
>df/dx is singular at some point.  Does this show any behavior not seen
>in maps involving analytic functions?

I've done some experimenting with maps x[n+1] = x^(-n)+C.  The main
difference I noted with this map is that the map doesn't diverge to
infinity.  (I.e. infinity gets mapped back C, as opposed to the mandelbrot
set, where infinity is mapped to infinity.)

I guess rational polynomial functions (i.e. P(x)/Q(x)) have singular points.
Their behavior isn't very different from polynomial functions, although
there are a few differences (I can't remember the details).

A good reference for rational polynomial fractals is:
%T Complex Analytic Dynamics on the Riemann Sphere
%A P. Blanchard
%J Bull. of the Amer. Math. Soc
%V 11
%N 1
%D July 1984
%P 85-141

(I highly recommend that paper for anyone interested in the mathematical
side of fractals.)

Ken Shirriff				shirriff@sprite.Berkeley.EDU
Technical Details
Message-ID: <1dkbg8INNkof@agate.berkeley.edu>
Path: arc1-ca.pugleaf.net!sparky!uunet!think.com!ames!agate!sprite.berkeley.edu!shirriff
References: <1992Nov8.234155.14813@mnemosyne.cs.du.edu>

Show Full Headers
Complete Article Headers
Path: arc1-ca.pugleaf.net!sparky!uunet!think.com!ames!agate!sprite.berkeley.edu!shirriff
From: shirriff@sprite.berkeley.edu (Ken Shirriff)
Newsgroups: sci.fractals
Subject: Re: Mappings with singular points
Date: 9 Nov 1992 00:31:04 GMT
Organization: University of California, Berkeley
Lines: 28
Message-ID: <1dkbg8INNkof@agate.berkeley.edu>
References: <1992Nov8.234155.14813@mnemosyne.cs.du.edu>
NNTP-Posting-Host: sabotage.berkeley.edu