title: How to display Python Crash Course Chapter 15 histogram using matplotlib
body: <p>So I am doing problems in the Python Crash Course book and in the end of Chapter 15 'Try it Yourself' section problem 15-10 you are tasked with "Try using a matplotlib to make a die-rolling visualization..." I have all the information laid out and have no errors, but when the program runs the histogram displays the graph and axis, but doesn't display the actual data. Does someone know why this is occurring and what I am missing?</p>
  
  <p>There is a module and class called Die() that initializes and randomly creates rolls. This class and program works perfectly, and is called on in the program below. </p>
  
  <h1>Dice Frequency Histogram Application</h1>
  
  <pre><code>import matplotlib
  import matplotlib.pyplot as plt
  from die import Die
  
  # create two D6 dice
  die_1 = Die()
  die_2 = Die()
  
  # make some rolls, and store results in a list.
  results = []
  for roll_num in range(5000):
      result = die_1.roll() + die_2.roll()
      results.append(result)
  
  # analyze the results.
  frequencies = []
  max_result = die_1.num_sides + die_2.num_sides
  for value in range(2, max_result+1):
      frequency = results.count(value)
      frequencies.append(frequency)
  
  plt.bins = []
  x_max = die_1.num_sides + die_2.num_sides
  for label in range(2, x_max+1):
      plt.bins.append(label)
  print(frequencies)
  plt.hist(frequencies, plt.bins, histtype = 'bar', facecolor = 'blue')
  
  plt.title("Dice Plot")
  plt.xlabel("Results")
  plt.ylabel("Frequency of Result")
  plt.axis([0,12,0,300])
  plt.show()
  </code></pre>
  
  <p>I'm expecting to get a Normal curve model-ish looking set of data. However, I get no data displayed instead. Again, the graph and axis are displayed, but the actual data is not.</p>