old_contents: import numpy as np
  import triangle
  import astropy.io.ascii as ascii
  import matplotlib.pyplot as plt
  
  pyout = ascii.read('test.pyout')
  idlout = ascii.read('test.idlout')
  
  fig, axarr = plt.subplots(9, 9, figsize=(10, 10))
  triangle.corner(np.array([pyout['alpha'], pyout['beta'], pyout['sigsqr'], 
                            pyout['mu0'], pyout['usqr'], pyout['wsqr'],
                            pyout['ximean'], pyout['xisig'], pyout['corr']]).T, 
                  labels=[r"$\alpha$", r"$\beta$", r"$\sigma^2$", 
                          r"$\mu_0$", r"$u^2$", r"$w^2$",
                          r"$\bar{\xi}$", r"$\sigma_\xi$", r"$\rho_{\xi\eta}$"],
                  extents=[0.99]*9,
                  fig=fig)
  triangle.corner(np.array([idlout['alpha'], idlout['beta'], idlout['sigsqr'], 
                            idlout['mu0'], idlout['usqr'], idlout['wsqr'],
                            idlout['ximean'], idlout['xisig'], idlout['corr']]).T, 
                  extents=[0.99]*9,
                  fig=fig, color='r')
  plt.show()
  
new_contents: import numpy as np
  import triangle
  import astropy.io.ascii as ascii
  import matplotlib.pyplot as plt
  
  pyout = ascii.read('test.pyout')
  idlout = ascii.read('test.idlout')
  
  fig, axarr = plt.subplots(9, 9, figsize=(10, 10))
  triangle.corner(np.array([pyout['alpha'], pyout['beta'], pyout['sigsqr'], 
                            pyout['mu0'], pyout['usqr'], pyout['wsqr'],
                            pyout['ximean'], pyout['xisig'], pyout['corr']]).T, 
                  labels=[r"$\alpha$", r"$\beta$", r"$\sigma^2$", 
                          r"$\mu_0$", r"$u^2$", r"$w^2$",
                          r"$\bar{\xi}$", r"$\sigma_\xi$", r"$\rho_{\xi\eta}$"],
                  extents=[0.99]*9, plot_datapoints=False,
                  fig=fig)
  triangle.corner(np.array([idlout['alpha'], idlout['beta'], idlout['sigsqr'], 
                            idlout['mu0'], idlout['usqr'], idlout['wsqr'],
                            idlout['ximean'], idlout['xisig'], idlout['corr']]).T, 
                  extents=[0.99]*9, plot_datapoints=False,
                  fig=fig, color='r')
  plt.show()
  
subject: exclude data points in triangle