diff options
Diffstat (limited to 'src/python/gudhi/cubical_complex.pyx')
| -rw-r--r-- | src/python/gudhi/cubical_complex.pyx | 95 |
1 files changed, 80 insertions, 15 deletions
diff --git a/src/python/gudhi/cubical_complex.pyx b/src/python/gudhi/cubical_complex.pyx index 007abcb6..28fbe3af 100644 --- a/src/python/gudhi/cubical_complex.pyx +++ b/src/python/gudhi/cubical_complex.pyx @@ -27,19 +27,20 @@ __license__ = "MIT" cdef extern from "Cubical_complex_interface.h" namespace "Gudhi": cdef cppclass Bitmap_cubical_complex_base_interface "Gudhi::Cubical_complex::Cubical_complex_interface<>": - Bitmap_cubical_complex_base_interface(vector[unsigned] dimensions, vector[double] top_dimensional_cells) - Bitmap_cubical_complex_base_interface(string perseus_file) - int num_simplices() - int dimension() + Bitmap_cubical_complex_base_interface(vector[unsigned] dimensions, vector[double] top_dimensional_cells) nogil + Bitmap_cubical_complex_base_interface(string perseus_file) nogil + int num_simplices() nogil + int dimension() nogil cdef extern from "Persistent_cohomology_interface.h" namespace "Gudhi": cdef cppclass Cubical_complex_persistence_interface "Gudhi::Persistent_cohomology_interface<Gudhi::Cubical_complex::Cubical_complex_interface<>>": - Cubical_complex_persistence_interface(Bitmap_cubical_complex_base_interface * st, bool persistence_dim_max) - void compute_persistence(int homology_coeff_field, double min_persistence) - vector[pair[int, pair[double, double]]] get_persistence() - vector[int] betti_numbers() - vector[int] persistent_betti_numbers(double from_value, double to_value) - vector[pair[double,double]] intervals_in_dimension(int dimension) + Cubical_complex_persistence_interface(Bitmap_cubical_complex_base_interface * st, bool persistence_dim_max) nogil + void compute_persistence(int homology_coeff_field, double min_persistence) nogil + vector[pair[int, pair[double, double]]] get_persistence() nogil + vector[vector[int]] cofaces_of_cubical_persistence_pairs() nogil + vector[int] betti_numbers() nogil + vector[int] persistent_betti_numbers(double from_value, double to_value) nogil + vector[pair[double,double]] intervals_in_dimension(int dimension) nogil # CubicalComplex python interface cdef class CubicalComplex: @@ -79,7 +80,7 @@ cdef class CubicalComplex: perseus_file=''): if ((dimensions is not None) and (top_dimensional_cells is not None) and (perseus_file == '')): - self.thisptr = new Bitmap_cubical_complex_base_interface(dimensions, top_dimensional_cells) + self._construct_from_cells(dimensions, top_dimensional_cells) elif ((dimensions is None) and (top_dimensional_cells is not None) and (perseus_file == '')): top_dimensional_cells = np.array(top_dimensional_cells, @@ -87,11 +88,11 @@ cdef class CubicalComplex: order = 'F') dimensions = top_dimensional_cells.shape top_dimensional_cells = top_dimensional_cells.ravel(order='F') - self.thisptr = new Bitmap_cubical_complex_base_interface(dimensions, top_dimensional_cells) + self._construct_from_cells(dimensions, top_dimensional_cells) elif ((dimensions is None) and (top_dimensional_cells is None) and (perseus_file != '')): if os.path.isfile(perseus_file): - self.thisptr = new Bitmap_cubical_complex_base_interface(perseus_file.encode('utf-8')) + self._construct_from_file(perseus_file.encode('utf-8')) else: raise FileNotFoundError(errno.ENOENT, os.strerror(errno.ENOENT), perseus_file) @@ -100,6 +101,14 @@ cdef class CubicalComplex: "top_dimensional_cells or from a Perseus-style file name.", file=sys.stderr) + def _construct_from_cells(self, vector[unsigned] dimensions, vector[double] top_dimensional_cells): + with nogil: + self.thisptr = new Bitmap_cubical_complex_base_interface(dimensions, top_dimensional_cells) + + def _construct_from_file(self, string filename): + with nogil: + self.thisptr = new Bitmap_cubical_complex_base_interface(filename) + def __dealloc__(self): if self.thisptr != NULL: del self.thisptr @@ -150,8 +159,11 @@ cdef class CubicalComplex: if self.pcohptr != NULL: del self.pcohptr assert self.__is_defined() - self.pcohptr = new Cubical_complex_persistence_interface(self.thisptr, True) - self.pcohptr.compute_persistence(homology_coeff_field, min_persistence) + cdef int field = homology_coeff_field + cdef double minp = min_persistence + with nogil: + self.pcohptr = new Cubical_complex_persistence_interface(self.thisptr, 1) + self.pcohptr.compute_persistence(field, minp) def persistence(self, homology_coeff_field=11, min_persistence=0): """This function computes and returns the persistence of the complex. @@ -170,6 +182,59 @@ cdef class CubicalComplex: self.compute_persistence(homology_coeff_field, min_persistence) return self.pcohptr.get_persistence() + def cofaces_of_persistence_pairs(self): + """A persistence interval is described by a pair of cells, one that creates the + feature and one that kills it. The filtration values of those 2 cells give coordinates + for a point in a persistence diagram, or a bar in a barcode. Structurally, in the + cubical complexes provided here, the filtration value of any cell is the minimum of the + filtration values of the maximal cells that contain it. Connecting persistence diagram + coordinates to the corresponding value in the input (i.e. the filtration values of + the top-dimensional cells) is useful for differentiation purposes. + + This function returns a list of pairs of top-dimensional cells corresponding to + the persistence birth and death cells of the filtration. The cells are represented by + their indices in the input list of top-dimensional cells (and not their indices in the + internal datastructure that includes non-maximal cells). Note that when two adjacent + top-dimensional cells have the same filtration value, we arbitrarily return one of the two + when calling the function on one of their common faces. + + :returns: The top-dimensional cells/cofaces of the positive and negative cells, + together with the corresponding homological dimension, in two lists of numpy arrays of integers. + The first list contains the regular persistence pairs, grouped by dimension. + It contains numpy arrays of shape [number_of_persistence_points, 2]. + The indices of the arrays in the list correspond to the homological dimensions, and the + integers of each row in each array correspond to: (index of positive top-dimensional cell, + index of negative top-dimensional cell). + The second list contains the essential features, grouped by dimension. + It contains numpy arrays of shape [number_of_persistence_points, 1]. + The indices of the arrays in the list correspond to the homological dimensions, and the + integers of each row in each array correspond to: (index of positive top-dimensional cell). + """ + + assert self.pcohptr != NULL, "compute_persistence() must be called before cofaces_of_persistence_pairs()" + + cdef vector[vector[int]] persistence_result + output = [[],[]] + with nogil: + persistence_result = self.pcohptr.cofaces_of_cubical_persistence_pairs() + pr = np.array(persistence_result) + + ess_ind = np.argwhere(pr[:,2] == -1)[:,0] + ess = pr[ess_ind] + max_h = max(ess[:,0])+1 if len(ess) > 0 else 0 + for h in range(max_h): + hidxs = np.argwhere(ess[:,0] == h)[:,0] + output[1].append(ess[hidxs][:,1]) + + reg_ind = np.setdiff1d(np.array(range(len(pr))), ess_ind) + reg = pr[reg_ind] + max_h = max(reg[:,0])+1 if len(reg) > 0 else 0 + for h in range(max_h): + hidxs = np.argwhere(reg[:,0] == h)[:,0] + output[0].append(reg[hidxs][:,1:]) + + return output + def betti_numbers(self): """This function returns the Betti numbers of the complex. |