summaryrefslogtreecommitdiff
path: root/src/python/gudhi
diff options
context:
space:
mode:
Diffstat (limited to 'src/python/gudhi')
-rw-r--r--src/python/gudhi/representations/vector_methods.py17
-rw-r--r--src/python/gudhi/simplex_tree.pyx41
-rw-r--r--src/python/gudhi/subsampling.pyx2
3 files changed, 29 insertions, 31 deletions
diff --git a/src/python/gudhi/representations/vector_methods.py b/src/python/gudhi/representations/vector_methods.py
index 5ca127f6..cdcb1fde 100644
--- a/src/python/gudhi/representations/vector_methods.py
+++ b/src/python/gudhi/representations/vector_methods.py
@@ -323,22 +323,15 @@ class BettiCurve(BaseEstimator, TransformerMixin):
Returns:
numpy array with shape (number of diagrams) x (**resolution**): output Betti curves.
"""
- num_diag, Xfit = len(X), []
+ Xfit = []
x_values = np.linspace(self.sample_range[0], self.sample_range[1], self.resolution)
step_x = x_values[1] - x_values[0]
- for i in range(num_diag):
-
- diagram, num_pts_in_diag = X[i], X[i].shape[0]
-
+ for diagram in X:
+ diagram_int = np.clip(np.ceil((diagram[:,:2] - self.sample_range[0]) / step_x), 0, self.resolution).astype(int)
bc = np.zeros(self.resolution)
- for j in range(num_pts_in_diag):
- [px,py] = diagram[j,:2]
- min_idx = np.clip(np.ceil((px - self.sample_range[0]) / step_x).astype(int), 0, self.resolution)
- max_idx = np.clip(np.ceil((py - self.sample_range[0]) / step_x).astype(int), 0, self.resolution)
- for k in range(min_idx, max_idx):
- bc[k] += 1
-
+ for interval in diagram_int:
+ bc[interval[0]:interval[1]] += 1
Xfit.append(np.reshape(bc,[1,-1]))
Xfit = np.concatenate(Xfit, 0)
diff --git a/src/python/gudhi/simplex_tree.pyx b/src/python/gudhi/simplex_tree.pyx
index 813dc5c2..cdd2e87b 100644
--- a/src/python/gudhi/simplex_tree.pyx
+++ b/src/python/gudhi/simplex_tree.pyx
@@ -389,37 +389,39 @@ cdef class SimplexTree:
self.get_ptr().reset_filtration(filtration, min_dim)
def extend_filtration(self):
- """ Extend filtration for computing extended persistence. This function only uses the
- filtration values at the 0-dimensional simplices, and computes the extended persistence
- diagram induced by the lower-star filtration computed with these values.
+ """ Extend filtration for computing extended persistence. This function only uses the filtration values at the
+ 0-dimensional simplices, and computes the extended persistence diagram induced by the lower-star filtration
+ computed with these values.
.. note::
- Note that after calling this function, the filtration
- values are actually modified within the simplex tree.
- The function :func:`extended_persistence`
- retrieves the original values.
+ Note that after calling this function, the filtration values are actually modified within the simplex tree.
+ The function :func:`extended_persistence` retrieves the original values.
.. note::
- Note that this code creates an extra vertex internally, so you should make sure that
- the simplex tree does not contain a vertex with the largest possible value (i.e., 4294967295).
+ Note that this code creates an extra vertex internally, so you should make sure that the simplex tree does
+ not contain a vertex with the largest possible value (i.e., 4294967295).
+
+ This `notebook <https://github.com/GUDHI/TDA-tutorial/blob/master/Tuto-GUDHI-extended-persistence.ipynb>`_
+ explains how to compute an extension of persistence called extended persistence.
"""
self.get_ptr().compute_extended_filtration()
def extended_persistence(self, homology_coeff_field=11, min_persistence=0):
- """This function retrieves good values for extended persistence, and separate the diagrams
- into the Ordinary, Relative, Extended+ and Extended- subdiagrams.
+ """This function retrieves good values for extended persistence, and separate the diagrams into the Ordinary,
+ Relative, Extended+ and Extended- subdiagrams.
- :param homology_coeff_field: The homology coefficient field. Must be a
- prime number. Default value is 11.
+ :param homology_coeff_field: The homology coefficient field. Must be a prime number. Default value is 11.
:type homology_coeff_field: int
- :param min_persistence: The minimum persistence value (i.e., the absolute value of the difference between the persistence diagram point coordinates) to take into
- account (strictly greater than min_persistence). Default value is
- 0.0.
- Sets min_persistence to -1.0 to see all values.
+ :param min_persistence: The minimum persistence value (i.e., the absolute value of the difference between the
+ persistence diagram point coordinates) to take into account (strictly greater than min_persistence).
+ Default value is 0.0. Sets min_persistence to -1.0 to see all values.
:type min_persistence: float
- :returns: A list of four persistence diagrams in the format described in :func:`persistence`. The first one is Ordinary, the second one is Relative, the third one is Extended+ and the fourth one is Extended-. See https://link.springer.com/article/10.1007/s10208-008-9027-z and/or section 2.2 in https://link.springer.com/article/10.1007/s10208-017-9370-z for a description of these subtypes.
+ :returns: A list of four persistence diagrams in the format described in :func:`persistence`. The first one is
+ Ordinary, the second one is Relative, the third one is Extended+ and the fourth one is Extended-.
+ See https://link.springer.com/article/10.1007/s10208-008-9027-z and/or section 2.2 in
+ https://link.springer.com/article/10.1007/s10208-017-9370-z for a description of these subtypes.
.. note::
@@ -430,6 +432,9 @@ cdef class SimplexTree:
The coordinates of the persistence diagram points might be a little different than the
original filtration values due to the internal transformation (scaling to [-2,-1]) that is
performed on these values during the computation of extended persistence.
+
+ This `notebook <https://github.com/GUDHI/TDA-tutorial/blob/master/Tuto-GUDHI-extended-persistence.ipynb>`_
+ explains how to compute an extension of persistence called extended persistence.
"""
cdef vector[pair[int, pair[double, double]]] persistence_result
if self.pcohptr != NULL:
diff --git a/src/python/gudhi/subsampling.pyx b/src/python/gudhi/subsampling.pyx
index b11d07e5..46f32335 100644
--- a/src/python/gudhi/subsampling.pyx
+++ b/src/python/gudhi/subsampling.pyx
@@ -105,7 +105,7 @@ def pick_n_random_points(points=None, off_file='', nb_points=0):
def sparsify_point_set(points=None, off_file='', min_squared_dist=0.0):
"""Outputs a subset of the input points so that the squared distance
- between any two points is greater than or equal to min_squared_dist.
+ between any two points is greater than min_squared_dist.
:param points: The input point set.
:type points: Iterable[Iterable[float]]