On Thu, Feb 13, 2025 at 9:49 PM Lindsay Lawrence < lawrence.lindsayj...@gmail.com> wrote:
> A bit of searching came up with the paper with the haskell version > > https://www.cs.ox.ac.uk/people/jeremy.gibbons/publications/spigot.pdf > > Interestingly enough there is another version of PI in there, recursive, > based on the Gosper series, > that a faster... although it is based on a conjecture they haven't proven > in that paper. > > The picolisp version of that one is below ('tco' is a nice fit for it as > well!) > There was an error in the variable scoping of the function I posted in previous email. Here is the corrected version (de makePi (N) (let (G 1 R 180 S 60 I 2) (tco (G R S I N) (let (U (* 3 (+ (* 3 I) 1) (+ (* 3 I) 2) ) Y (/ (+ (* G (- (* 27 I) 12)) (* 5 R) ) (* 5 S) ) ) (prin Y) (if (or (not N) (gt0 N)) (tc (* 10 G I (- (* 2 I) 1)) (* 10 U (- (+ (* G (- (* 5 I) 2)) R) (* Y S) ) ) (* S U) (+ I 1) (dec N) ) ) ) ) )) /Lindsay
