#!/usr/koeki/bin/ruby

require 'gnuplot'

srand()
n = 10 # Ⱦ·Â
m = 1000 # »î¹Ô²ó¿ô

pt_x = Array.new
pt_y = Array.new
ct_r = 0
1.upto(m) do 
  x = rand(n)
  y = rand(n)
  if x ** 2 + y ** 2 < 10 ** 2
    ct_r += 1    
  end
  pt_x << x + 1
  pt_y << y + 1  
end

printf("pi = #{ct_r.to_f / m * 4}\n")

file = "dtd_pi.csv"
func = "sqrt(#{n**2} - x ** 2)"

Gnuplot.open do |gp|
  Gnuplot::Plot.new(gp) do |pl|
    pl.xrange "[0:11]"
    pl.yrange "[0:11]"
    pl.xlabel "x"
    pl.ylabel "y"
    pl.data << Gnuplot::DataSet.new( [pt_x, pt_y] ) do |ds|
      ds.notitle
    end
    pl.data << Gnuplot::DataSet.new(func) do |ds2|
    end
   end
 end