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))
  fig.suptitle("Black = python, red = IDL")
  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['mu00'], idlout['usqr'], idlout['wsqr'],
                            idlout['ximean'], idlout['xisig'], idlout['corr']]).T,
                  extents=[0.99]*9, plot_datapoints=False,
                  fig=fig, color='r')
  fig.subplots_adjust(bottom=0.065, left=0.07)
  plt.show()
  
new_contents: import numpy as np
  import corner
  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))
  fig.suptitle("Black = python, red = IDL")
  corner.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"$\rho_{\xi\eta}$"],
                range=[0.99]*9, plot_datapoints=False,
                fig=fig)
  corner.corner(np.array([idlout['alpha'], idlout['beta'], idlout['sigsqr'],
                          idlout['mu00'], idlout['usqr'], idlout['wsqr'],
                          idlout['ximean'], idlout['xisig'], idlout['corr']]).T,
                range=[0.99]*9, plot_datapoints=False,
                fig=fig, color='r')
  fig.subplots_adjust(bottom=0.065, left=0.07)
  plt.show()
  
subject: Use updated corner plot API