text: import numpy
  import random
  from matplotlib import pyplot
  
  
  fig = pyplot.figure(0)
  ax = fig.add_axes([0.1, 0.1, 0.8, 0.8])
  ax.clear()
  
  class Date( object ):
      def __init__(self):
          self.A = numpy.random.random()*60.0
          self.B = numpy.random.random()*60.0
  
      def success(self):
          return numpy.abs(self.A - self.B) < 15.0
  
  
  avg_1 = []
  success_1 = 0.0
  avg_2 = []
  success_2 = 0.0
  avg_3 = []
  success_3 = 0.0
  
  for i in range(1000000):
      d1 = Date()
      d2 = Date()
      d3 = Date()
      if d1.success():
          success_1 += 1.0
      avg_1.append(success_1/(i+1))
      if d2.success():
          success_2 += 1.0
      avg_2.append(success_2/(i+1))
      if d3.success():
          success_3 += 1.0
      avg_3.append(success_3/(i+1))
  
  
  ax.plot(avg_1, color = 'r')
  ax.plot(avg_2, color = 'b')
  ax.plot(avg_3, color = 'g')
  
  fig.show()
  
  fig.savefig('SuccessFraction.png")
  