message: doc review : modification of persistence barcode example to make it more relevant
diff: @@ -19,12 +19,15 @@ This function can display the persistence result as a barcode:
  import gudhi
  - perseus_file = gudhi.__root_source_dir__ + '/data/bitmap/3d_torus.txt'
  - periodic_cc = gudhi.PeriodicCubicalComplex(perseus_file=perseus_file)
  - diag = periodic_cc.persistence()
  - print("diag = ", diag)
  - plt = gudhi.plot_persistence_barcode(diag)
  - plt.show()
  + off_file = gudhi.__root_source_dir__ + '/data/points/tore3D_300.off'
  + point_cloud = gudhi.read_off(off_file=off_file)
  +
  + rips_complex = gudhi.RipsComplex(points=point_cloud, max_edge_length=0.7)
  + simplex_tree = rips_complex.create_simplex_tree(max_dimension=3)
  + diag = simplex_tree.persistence(min_persistence=0.4)
  +
  + plot = gudhi.plot_persistence_barcode(diag)
  + plot.show()
  Show persistence as a diagram
  -----------------------------
  @@ -53,13 +56,9 @@ If you want more information on a specific dimension, for instance:
  import gudhi
  + # rips_on_tore3D_1307.pers obtained from write_persistence_diagram method
  persistence_file=gudhi.__root_source_dir__ + \
  '/data/persistence_diagram/rips_on_tore3D_1307.pers'
  - diag = \
  - gudhi.read_persistence_intervals_grouped_by_dimension(persistence_file=\
  - persistence_file)
  - dim = 1
  - # Display persistence density
  - plt = gudhi.plot_persistence_density([(dim,interval) for interval in diag[dim]],
  - max_plots=0, legend=True)
  + plt = gudhi.plot_persistence_density(persistence_file=persistence_file,
  + max_plots=0, dimension=1, legend=True)
  plt.show()
  