Thread Rating:
  • 0 Vote(s) - 0 Average
  • 1
  • 2
  • 3
  • 4
  • 5
Find all fixed points of exp[b]
#11
(10/07/2014, 01:50 AM)mike3 Wrote: Addendum: You can replace Wapprox with this:

Code:
Wapprox(k, z) = {
   local(brl = brlog(k, z));
   local(lbrl = log(brl));

   return(brl - lbrl + sum(kk=0,5,sum(m=1,5,c(kk, m)*lbrl^m * brl^(-kk-m))));
}

to get even more speed (saves some repeated log calculations).
Hi Mike -

very well, thank you! I've also made the coefficients c() constants in a small matrix, because your routine uses them only to small arguments but repeatedly, also made Pi2I a constant. I've got 120 frixpoints to base 4 with 200 digits precision in 656 ms on a 2 Ghz machine. Great!

Gottfried
Gottfried Helms, Kassel
Reply


Possibly Related Threads...
Thread Author Replies Views Last Post
  fixed point formula sheldonison 6 5,197 05/23/2015, 04:32 AM
Last Post: mike3
  Attempt to find a limit point but each step needs doubling the precision... Gottfried 15 7,668 11/09/2014, 10:25 PM
Last Post: tommy1729
  sexp(strip) is winding around the fixed points Kouznetsov 8 7,867 06/29/2009, 10:05 AM
Last Post: bo198214
  An error estimate for fixed point computation of b^x bo198214 0 1,584 05/31/2008, 04:11 PM
Last Post: bo198214



Users browsing this thread: 1 Guest(s)