Re: Optimizing fixed point iteration

*To*: mathgroup at smc.vnet.net*Subject*: [mg83100] Re: Optimizing fixed point iteration*From*: Yaroslav Bulatov <yaroslavvb at gmail.com>*Date*: Sun, 11 Nov 2007 02:54:37 -0500 (EST)*References*: <200711091017.FAA12104@smc.vnet.net><fh3rmu$13o$1@smc.vnet.net>

Sorry, only checked code with a non-fresh kernel, it should be depth; to terminate in reasonable time, although greater depth would give more detail On Nov 10, 12:55 am, Murray Eisenberg <mur... at math.umass.edu> wrote: > What value of depth are you trying to use?? > > 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 > > -- > Murray Eisenberg mur... at math.umass.edu > Mathematics & Statistics Dept. > Lederle Graduate Research Tower phone 413 549-1020 (H) > University of Massachusetts 413 545-2859 (W) > 710 North Pleasant Street fax 413 545-1801 > Amherst, MA 01003-9305

**Follow-Ups**:**Re: Re: Optimizing fixed point iteration***From:*Murray Eisenberg <murray@math.umass.edu>

**References**:**Optimizing fixed point iteration***From:*Yaroslav Bulatov <yaroslavvb@gmail.com>