
  QPI - Quick Pi Copyright(C)2000 by Steve Pagliarulo.

 ( This is version 1.0, a Win32 console program for the
   PC platform. CPU: i386+ using MS Visual C++ 6.0 )

    Text file (QuickPi.txt) created by The Starman.
 You can download qpi.exe from The Starman's Realm here:
 http://www.geocities.com/thestarman3/math/pi/df/qpi10.zip

    QuickPi calculates Pi using a default formula from the
 Chudnovsky brothers. Simply enter: qpi at a command prompt
 and it will display its usage information along with 400
 digits of Pi.

    Besides computing Pi, by adding either the parameter
 -2 or -e to the command line, this program can also carry
 out the square-root of 2 (using Newton's iteration method)
 or compute e (using the series SUM of 1/n!).

    For Pi itself, the program can use the following formulas:
 one from the Chudnovsky brothers [default], a Gauss-Legendre
 AGM [-a], the Brent-Salamin AGM [-s], or a quartic from the
 Borwein brothers [-b].

 Program usage:  qpi [digits] [-2|-e|-a|-s|-b]


    Apparently, Steve included the other methods for some
 comparison purposes as the default method (Chudnovsky) is
 the fastest of all four for computing Pi. On my old 100MHz
 machine, the times I got for computing 512,000 digits of
 Pi were:

     default (Chudnovsky brothers) =  80.94 seconds
           -a (Gauss-Legendre AGM) = 159.70 seconds
            -s (Brent-Salamin AGM) = 192.38 seconds
    -b (Borwein brother's quartic) = 235.64 seconds

 You can also see that he listed the methods in his usage
 statement in the order of their speed as well (-a, -s, -b).


    For more information about Pi, please visit my
 "Pi Files" pages at:

 http://www.geocities.com/thestarman3/math/pi/index.html

 Or, contact me using this form:
 http://www.geocities.com/thestarman3/Feedback.html

 [The Starman, July 4th, 2001.]
