Thread Rating:
  • 0 Vote(s) - 0 Average
  • 1
  • 2
  • 3
  • 4
  • 5
complex base tetration program
#20
(02/06/2016, 05:36 PM)Gottfried Wrote: Discussing the (extended) Kneser-method the question of fixpoints is relevant. Here I have produced a picture of the fixpoints of tetration to base(î) , I found 2 simple fixpoint (attracting for exp, attracting for log, both used for the Kneser-method), and three periodic points - making things a bit more complicated. The fixpoints were sought using the Newton-algorithm for the joint threefold exponentiation and the iteration .

This means for example, that for the point in the top-left edge with the blue color having the z-value z_0=-5 - 5i the Newton-algorithm using iteration arrives at the fixpoint 3.0 (having the complex value of about -1.14+0.71I in a moderate number of iterations. The blue point at coordinate z_0=-2.5+1I needs less iterations and the a bit lighter blue points near the periodic point 3.0 need even less iterations.

Perhaps this post should be moved into a discussion of the Kneser-method or of the general problem of fixpoints.

Gottfried

Here is the picture:

Yes, this thread should be moved; it has to do with fatou.gp, and an MSE question for tetration base(i), and the two primary fixed points for Henryk Trapmann's uniqueness sickle.

In the case at hand, the other fixed point, for the lower half of the complex plane for sexp(z), is -1.862-0.411i, which Gottfried has listed strangely as 3-periodic, where as it is a simple repelling fixed point for . The Abel/Slog uniqueness sickle connects the two primary fixed points. For exp(z), both fixed points are repelling for exp(z). But if you move slowly from base(e), to base(i), you see the lower fixed point becomes -1.862-0.411i, which is still repelling, but the upper fixed point becomes attracting; 0.4383+0.3606i. The solution I posted on MSE is based on generated the slog(z) exactly between the two primary fixed points, which is what the fatou.gp program does. My answer on MSE includes the taylor series for p(z), which turns out to have a remarkably mild singularity at the two fixed points; finding that analytic Taylor series is the basis for the fatou.gp program solution, which leads directly to Henryk's uniqueness sickle.

Abel function
- Sheldon
Reply


Messages In This Thread
complex base tetration program - by sheldonison - 02/29/2012, 10:28 PM
RE: complex base tetration program - by mike3 - 03/10/2012, 06:59 AM
RE: complex base tetration program - by mike3 - 03/11/2012, 12:27 AM
RE: complex base tetration program - by Gottfried - 02/06/2016, 01:37 AM
RE: complex base tetration program - by Gottfried - 02/06/2016, 05:36 PM
RE: complex base tetration program - by Gottfried - 02/07/2016, 05:27 AM
RE: complex base tetration program - by sheldonison - 02/07/2016, 12:28 PM
RE: complex base tetration program - by Gottfried - 02/07/2016, 01:25 PM
RE: complex base tetration program - by Gottfried - 10/24/2016, 11:50 PM
RE: complex base tetration program - by Gottfried - 10/26/2016, 10:02 AM

Possibly Related Threads...
Thread Author Replies Views Last Post
Wink new fatou.gp program sheldonison 20 18,709 02/11/2020, 04:47 PM
Last Post: sheldonison
  Natural complex tetration program + video MorgothV8 1 1,713 04/27/2018, 07:54 PM
Last Post: MorgothV8
  Mathematica program for tetration based on the series with q-binomial coefficients Vladimir Reshetnikov 0 1,974 01/13/2017, 10:51 PM
Last Post: Vladimir Reshetnikov
  C++ program for generatin complex map in EPS format MorgothV8 0 2,609 09/17/2014, 04:14 PM
Last Post: MorgothV8
  Green Eggs and HAM: Tetration for ALL bases, real and complex, now possible? mike3 27 33,887 07/02/2014, 10:13 PM
Last Post: tommy1729
  "Kneser"/Riemann mapping method code for *complex* bases mike3 2 6,626 08/15/2011, 03:14 PM
Last Post: Gottfried
  fractional iteration with complex bases/a bit of progress Gottfried 1 3,786 07/21/2008, 10:58 PM
Last Post: Gottfried



Users browsing this thread: 1 Guest(s)