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Name: existing
Status: N/A
Age: N/A
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Date: Around 1995

Currently what is the fastest algorithm for computing pi?

I do not know the details, but I know it is complicated. I think they use some of the tan formulas. I believe there was a Scientific American article on this somewhere between 5 and 10 years back. In any case, one part of the problem is how to store all those digits, and how to multiply numbers with that many digits, etc. I believe eventually (when you get to billions of digits) the fastest multiplication of such numbers is by a convolution approach using a Fast Fourier Transform! Of course, if you only want a small number of digits its not that bad!


The article asmith refers to was in the February 1988 issue of Scientific American. Entitled "Ramanujan and pi", it gives a number of formulas for the calculation of pi (including the one used by the article's authors, who were the record holders for digits at the time the article was written). There is also a nice capsule history of the calculation of pi and some information on the amazing Indian mathematician Ramanujan. Highly recom- mended reading.


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