This is totally the wrong venue for this question, but just in case you're still struggling with it a year later I happen to know the answer.
Computing persistent homology has two steps:
- Turn the point cloud into a filtration of simplicial complexes
- Compute the homology of the simplicial complex
The "filtration" part of step 1 means you have to compute a simplicial complex for a whole range of parameters. The parameter in this case is epsilon, the distance threshold within which points are connected. The max_f
variable caps the range of epsilon sweep from zero to max_f
.
plotPersistenceDiagram
displays the homological "persistence barcodes" as points instead of lines. The x-coordinate of the point is the birth time of that topological feature (the value of epsilon for which it first appears), and the y-coordinate is the death time (the value of epsilon for which it disappears).