code: def plot_one_digit_freqs(f1):
      """
      Plot one digit frequency counts using matplotlib.
      """
      ax = plt.plot(f1, "bo-")
      plt.title("Single digit counts in pi")
      plt.xlabel("Digit")
      plt.ylabel("Count")
      return ax
  
file_path: ipyparallel/examples/pi/pidigits.py
imports: import os
  from urllib.request import urlretrieve
  import numpy
  from matplotlib import pyplot
label_desc: Use image node_id 11 for calling a global function with example usage: plot_one_digit_freqs(f1) and returns: ax