text: import numpy as np
  import matplotlib.pyplot as plt
  import helper
  
  prec = np.float64
  
  solutions = ["rk4_ed", "rk4_ec3", "srk4_opt"]
  labels = ["PMF-ED", "EC3", "EC2"]
  p0 = {}
  p1 = {}
  t = {}
  dlabels = {}
  
  for lbl, soln in zip(labels, solutions):
      p0[soln], p1[soln], t[soln] = helper.load(soln, 2, prec)
      dlabels[soln] = lbl
  
  for i, soln in enumerate(solutions):
      plt.plot(t[soln], p0[soln] - p1[soln], "C%d" % i, label=dlabels[soln])
      #plt.plot(t[soln], , "C%d" % i, label=dlabels[soln])
  #plt.plot(t, q0-q1, label="EC-OPT")
  #plt.plot(t, w0-w1, label="ED")
  plt.legend()
  plt.show()
  
  