Alpha shapes
------------

.. image:: figures/alpha-shape.png
   :scale: 50 %
   :align: center

::

    >>> points = read_points('data/trefoil.pts')
    >>> f = alpha_complex(points)
    >>> print("Filtration size:", len(f))

::

    >>> show_complex(points, [s for s in f if s.data < 1])

