new_contents: import sys
  import datetime as dt
  import matplotlib.pyplot as plt
  import numpy as np
  import matplotlib as mpl
  
  """
  Diurnal_Plot.py: 
  
      Produce diurnal plots of fitbit data (5 min intervals). 
      Inspired by Stephen Wolfram's "The Personal Analytics of my Life"
      (http://blog.stephenwolfram.com/2012/03/the-personal-analytics-of-my-life/) 
  
      Call with fitbit data as first argument. 
  """
  
  if __name__=='__main__': 
      filename = sys.argv[1]
      minutes_in_day = (24 * 60) 
      X   = [] 
      Y   = [] 
      values = []
      with open(filename,'r') as f: 
          day_num = -1
          day = None
          time_num = 0
          for l in f: 
              
              parts   = l.split(",")
              date_s  = parts[0]
              value   = int(parts[1]) 
              datet   = dt.datetime.strptime(date_s, "%Y-%m-%d %H:%M")
              if day != datet.date():
                  day_num = day_num + 1
                  day = datet.date()
             
  
              if value > 0: 
                  values.append(value)
                  X.append(datet.date()) 
                  Y.append(minutes_in_day - (datet.time().hour * 60 + datet.time().minute))
  
      #Y axis locations
      locations = np.arange(0,24)*60
  
      #Y axis labels
      labels    = ["%d:00" % ((24*60 - x) /60) for x in locations]
  
      ax = plt.scatter(X,Y, c=values, s=3, facecolor='0.5', lw = 0, cmap=mpl.cm.YlGnBu)
      plt.ylim([0,minutes_in_day]) 
      plt.yticks(locations,labels)
      plt.savefig("FitbitData.png", fmt="png"); 
  
subject: Add very basic diurnal plotter