Topics

Persistent diagram of one-dimensional data

Mahdi Kooshkbaghi
 

Dear Dimitry,
Thank you very much. Even your short description solve my conceptual problem.
Best,
Mahdi

Dmitriy Morozov
 

Hi Mahdi,

Below is an example that does what you want, I think. It boils down to generating the lower-star filtration of a piecewise-linear function whose values you give as a NumPy array [1]. The plot of the persistence diagram is missing the point at infinity, although the diagram itself (dgm[0]) has that point.


Dmitriy

import dionysus as d
import numpy as np
import matplotlib.pyplot as plt

a = np.array([10,4,7,3,9,2,12], dtype='f4')
plt.plot(a)
plt.show()

f = d.fill_freudenthal(a)
p = d.homology_persistence(f)
dgm = d.init_diagrams(p,f)

d.plot.plot_diagram(dgm[0], show=True)


On Tue, Mar 20, 2018 at 2:28 PM, <mahdik@...> wrote:
Dear all,
It could be more conceptual issue about the topic rather than software issue.
I wonder how can I generate persistent diagrams for the scalar field via Dionysus?
I have attached the figure from "Persistent homology survey by H. E. and J. H".
I am trying to understand and plot something similar.
Thanks,
Mahdi
PS: for two and more-dimensional data I can understand and play with package to get the persistence diagrams.


Mahdi Kooshkbaghi
 

Dear all,
It could be more conceptual issue about the topic rather than software issue.
I wonder how can I generate persistent diagrams for the scalar field via Dionysus?
I have attached the figure from "Persistent homology survey by H. E. and J. H".
I am trying to understand and plot something similar.
Thanks,
Mahdi
PS: for two and more-dimensional data I can understand and play with package to get the persistence diagrams.