cechmate.filtrations.Alpha

class cechmate.filtrations.Alpha(verbose=None)[source]

Construct an Alpha filtration from the given data.

Note

Alpha filtrations use radius instead of diameter. Multiply results or X by 2 when comparing the filtration to Rips or Cech.

Examples

>>> r = Alpha()
>>> simplices = r.build(X)
>>> diagrams = r.diagrams(simplices)
__init__(verbose=None)[source]

Default constructor

Parameters:verbose (boolean) – If True, then print logging statements.

Methods

__init__([verbose]) Default constructor
build(X) Do the Alpha filtration of a Euclidean point set (requires scipy)
diagrams([simplices, show_inf]) Compute persistence diagrams for the simplices.
build(X)[source]

Do the Alpha filtration of a Euclidean point set (requires scipy)

Parameters:X (Nxd array) – Array of N Euclidean vectors in d dimensions
diagrams(simplices=None, show_inf=False)

Compute persistence diagrams for the simplices.

Parameters:
  • simplices – simplices or filtration built from build method.
  • show_inf (Boolean) – Determines whether or not to return points that never die.
Returns:

dgms (list of diagrams) – the persistence diagram for Hk