Happy Pi Day!

[Gerson W. Barbosa]

(12-12-2021 06:44 PM)DM48 Wrote:  Gerson, below is part of a python spigot algo my son uses to calculate PI. The range 10,000,000 would need to be reduced a lot for the HP48G. Any thoughts on the best way to program this up in RPL?
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Hi,

Pi Day 2022 is still a bit away, but this is not a problem. The problem is I do not understand Python. Anyway, I may give it a try later if I figure out how it works.
In Pi Day 2009 Egan Ford presented a comprehensive collection of programs to calculate Pi, including "HP-71B Spigot Forth" (1000 digits in 6720.22 seconds). Perhaps it should be easier to convert that one to RPL.

https://www.hpmuseum.org/cgi-sys/cgiwrap...ead=148399

Regarding the formula in the OP, I've found a nicer one. An RPL program is also offered in the vein "it's slow but it's mine" :-) (357 decimal digits in 3820.207 seconds)