Re: Optimizing fixed point iteration
- To: mathgroup at smc.vnet.net
- Subject: [mg83101] Re: Optimizing fixed point iteration
- From: David Bailey <dave at Remove_Thisdbailey.co.uk>
- Date: Sun, 11 Nov 2007 02:55:08 -0500 (EST)
- References: <fh1ckb$csj$1@smc.vnet.net>
Yaroslav Bulatov wrote:
> Can anyone see the trick to speed up the following code significantly?
>
> depth;step=.02;
> Table[(c = 0;
> NestWhile[-4 (# - a) (# - b) &, .51, (c++; Abs[#1 - #2] > .1) &, 2,
> depth]; c), {a, -1., 0., step}, {b, 0., 1., step}] // ArrayPlot
>
> This makes a plot of the number of iterations needed for the quadratic
> fixed point iterations to converge, as a function of quadratic
> parameters, however it's too slow to get sufficient granularity
>
>
Are you perhaps under the misconception that your first line has set
your 'depth' variable?
David Bailey
http://www.dbaileyconsultancy.co.uk