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University of Birmingham


Root(2) and PI computations


Check  out my Square Root 2 applet which uses the Bhaskara-Brouckner algorithm to compute root(2) to any number of decimal places. This is about the fastest algorithm I have found to do this computation but if you know different, please email me. I have checked this algorithm for the first million or so decimal places by comparing it with those posted at The NASA Goddard Flight Centre  web-site (err not by hand. I wrote a program to do it!). The algorithm makes extensive use of Java's BigInteger class.

Also try out my  PI applet which uses the BPP formula (named after
Bailey-Borwein-Plouffe) to compute each hexadecimal digit of PI as a ratio of polynomials.  It is a simple matter to convert these to decimal digits. The applet is fairly slow and takes a couple of minutes for 10000 decimal places. I must admit I have only checked this for the first 10000 decimal places. Please email me if you find any errors. Again this uses Java's BigInteger class to do the donkey work. (Does anyone remember that old  Star Trek episode where Spock ties up the ship's computer by getting it to compute PI to infinite accuracy thus stopping some alien force taking control?)