old_contents: #!/usr/bin/env python
  
  import numpy as np
  import matplotlib.pyplot as plt
  
  for kbT in ['1', '2.25', '3', '50', '1000']:
      t, Eu, Eu_, Er, Er_ = np.loadtxt('{}.txt'.format(kbT), unpack=True)
      plt.plot(t, Eu, label='Uniform')
      plt.plot(t, Er, label='Random')
      plt.xlabel('$t$')
      plt.xscale('log')
      plt.ylabel(r'$E = \langle\mathcal{H}\rangle$')
      plt.legend(loc='best')
      plt.title('$k_BT = {}$'.format(kbT))
      plt.savefig('{}.png'.format(kbT))
      plt.clf()
  
new_contents: #!/usr/bin/env python
  
  import numpy as np
  import matplotlib.pyplot as plt
  
  for kbT in ['1', '2.25', '3', '50', '1000']:
      t, Eu, Eu_, Er, Er_ = np.loadtxt('{}.txt'.format(kbT), unpack=True)
      plt.plot(t, Eu, label='Uniform')
      plt.plot(t, Er, label='Random')
      plt.xlabel('$t$')
      plt.xscale('log')
      plt.ylim(-21000, 0)
      plt.ylabel(r'$E = \langle\mathcal{H}\rangle$')
      plt.legend(loc='best')
      plt.title('$k_BT = {}$'.format(kbT))
      plt.savefig('{}.png'.format(kbT))
      plt.clf()
  
subject: fix y-axis limit for E-plot