text: # Plot evenly spaced streamlines for cylinder in a crossflow.
  # This dataset is a multiblock dataset, and the fluid velocity is in the
  # first block.
  #
  import pyvista
  from pyvista import examples
  mesh = examples.download_cylinder_crossflow()
  streams = mesh[0].streamlines_evenly_spaced_2D(start_position=(4, 0.1, 0.),
                                                 separating_distance=3,
                                                 separating_distance_ratio=0.2)
  plotter = pyvista.Plotter()
  _ = plotter.add_mesh(streams.tube(radius=0.02), scalars="vorticity_mag")
  plotter.view_xy()
  plotter.show()
  