content: #!/usr/bin/python
  
  import sys
  import os
  import matplotlib
  
  import numpy
  import matplotlib
  matplotlib.use('AGG')
  import matplotlib.pyplot as plt
  from matplotlib.ticker import MaxNLocator
  from matplotlib.ticker import FormatStrFormatter
  
  
  def getArg(param, default=""):
      if (sys.argv.count(param) == 0): return default
      i = sys.argv.index(param)
      return sys.argv[i + 1]
  
  lastsecs = int(getArg("lastsecs", 240))
  
  fname = sys.argv[1]
  try:
  	tdata = numpy.loadtxt(fname, delimiter=" ")
  except:
  	exit(0)
  
  
  if len(tdata.shape) < 2 or tdata.shape[0] < 2 or tdata.shape[1] < 2:
      print "Too small data - do not try to plot yet."
      exit(0)
  
  times = tdata[:, 0]
  values = tdata[:, 1]
  
  lastt = max(times)
  
  
  #majorFormatter = FormatStrFormatter('%.2f')
  
  fig = plt.figure(figsize=(3.5, 2.0))
  plt.plot(times[times > lastt - lastsecs], values[times > lastt - lastsecs])
  plt.gca().xaxis.set_major_locator( MaxNLocator(nbins = 7, prune = 'lower') )
  plt.xlim([max(0, lastt - lastsecs), lastt])
  #plt.ylim([lastt - lastsecs, lastt])
  
  plt.gca().yaxis.set_major_locator( MaxNLocator(nbins = 7, prune = 'lower') )
  
  #plt.gca().yaxis.set_major_formatter(majorFormatter)
  plt.savefig(fname.replace(".dat", ".png"), format="png", bbox_inches='tight')
  
  
  