Revisting my accelerated slog solution using Abel matrix inversion
#18
I added a criitical clarification on how to calculate \( \theta_s(z) \) in my previous post.

\( \theta_s(z)=\text{KneserSlog}(\alpha^{-1}(z))-z;\;\; \) plugging in the complex valued superfunction
\( \theta_s(z)\approx\text{JaySlog}(\alpha^{-1}(z))+\theta_{Rj}\left(\text{JaySlog}(\alpha^{-1}(z))\right)-z;\;\; \) approximation for Kneser's slog from Jay's slog; from above

So this gives us an equation for \( \theta_s \) in terms of Jay's slog with Jay's slog \( \theta_{Rj} \).  We sample the superfunction, \( \alpha^{-1}(z) \) at a set of equally spaced points, and then use those samples points to take the Fourier transform of \( \theta_s \) at those sample points.  Then we drive the undesired terms of the \( \theta_s \) fourier transform to zero in terms of the \( \theta_{Rj} \) unknown terms by a matrix simultaneous equation solution.

The programming is complicated, because we need a the complex valued Schroder function and its inverse, plus lots of other details.  I will post the pari-gp code, once I finish cleaning it up a little more, along with some results. Anyway, remarkably this all works and generates superbly accurate results for Kneser's slog in terms of Jay's slog and a 1-cyclic real valued fourier transform which is calculated via a matrix simultaneous equation in terms of the Schroder function.  The results are generated without starting with Kneser's slog, but match Kneser's slog much better than one would have naively predicted since the \( \alpha^{-1}(z) \) samples can be chosen to take maximum advantage of the peculiar peanut shaped convergence region of Jay's slog.  More later...
- Sheldon
Reply


Messages In This Thread
Analysis of Jay's slog vs Kneser - by sheldonison - 01/17/2019, 06:44 PM
RE: Analysis of Jay's slog vs Kneser - by jaydfox - 01/18/2019, 06:35 AM
RE: Analysis of Jay's slog vs Kneser - by jaydfox - 01/18/2019, 06:42 AM
RE: Analysis of Jay's slog vs Kneser - by jaydfox - 01/18/2019, 06:17 PM
RE: Revisting my accelerated slog solution using Abel matrix inversion - by sheldonison - 01/29/2019, 09:15 PM

Possibly Related Threads…
Thread Author Replies Views Last Post
  Terse Schroeder & Abel function code Daniel 1 3,792 10/16/2022, 07:03 AM
Last Post: Daniel
  Quickest way to compute the Abel function on the Shell-Thron boundary JmsNxn 0 3,766 04/21/2022, 01:52 AM
Last Post: JmsNxn
  The Promised Matrix Add On; Abel_M.gp JmsNxn 2 5,843 08/21/2021, 03:18 AM
Last Post: JmsNxn
  An incremental method to compute (Abel) matrix inverses bo198214 3 20,217 07/20/2010, 12:13 PM
Last Post: Gottfried
  A note on computation of the slog Gottfried 6 26,101 07/12/2010, 10:24 AM
Last Post: Gottfried
  Improving convergence of Andrew's slog jaydfox 19 67,492 07/02/2010, 06:59 AM
Last Post: bo198214
  intuitive slog base sqrt(2) developed between 2 and 4 bo198214 1 10,067 09/10/2009, 06:47 PM
Last Post: bo198214
  SAGE code for computing flow matrix for exp(z)-1 jaydfox 4 22,086 08/21/2009, 05:32 PM
Last Post: jaydfox
  sexp and slog at a microcalculator Kouznetsov 0 7,239 01/08/2009, 08:51 AM
Last Post: Kouznetsov
  Convergence of matrix solution for base e jaydfox 6 22,902 12/18/2007, 12:14 AM
Last Post: jaydfox



Users browsing this thread: 1 Guest(s)