Erm, I rewrote this in ruby:

#!/usr/bin/env ruby # $Id: MonteCarlo.rb 146 2010-10-14 20:43:47Z sam $ # Our main class class MonteCarlo # We will automagically generate reader methods for these attributes attr_reader :pi, :count, :hits # Constructor: set everything to zero before we start def initialize @hits = 0; @count = 0; @pi = 0; end # We call this method for every throw def increment hit # We always clock up another throw @count = @count + 1 # And accumulate a hit if we scored one @hits = @hits + 1 if hit # Then calulate a new value of pi calcpi end # Represent ourself as a string def to_s sprintf "Throws: %10d, Hits: %10d, Pi: %10f, Actual Pi: %10f", self.count, self.hits, self.pi, Math::PI end # Mark off the private elements of this class private # Calcluate pi def calcpi # explanation can be found here: http://icanhaz.com/montecarlo @pi = 4.0 * ((@hits.to_f) / (@count.to_f)) end # Class ends end # Class representing a single throw of a dart class Throw # Constructor: we only do one thing, so we may as well do it here (I'm sure # it's woefully inefficient to construct a new instance every time, but never # mind) def initialize # Generate two random coordinates (between 0 and 1) @x = rand @y = rand # The distance from the origin will be the hypotenuse of a right-angled # triangle with sides of length x and y. So from Pythagoras, we see that: # # @distance = sqrt((x^2) + (y^2)) # # which translates into Ruby as: @distance = ((@x * @x) + (@y * @y))**0.5 end # Method to determine whether our dart landed inside the quadrant def hit? # Return true if distance from origin is 1.0 or less @distance <= 1.0 end # Class ends end # Main code starts here # # First, contruct a new MonteCarlo object mc = MonteCarlo.new # Loop forever while 1 do # Every iteration, make a new Throw, see if we scored a 'hit', then hand this # as the parameter as we increment the count of total throws mc.increment Throw.new.hit? # Output every 1000th iteration puts mc if mc.count % 1000 == 0 end

The source was on my Subversion server, now lost to the mists of time.

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