diff options
Diffstat (limited to 'src/python/gudhi/simplex_tree.pyx')
| -rw-r--r-- | src/python/gudhi/simplex_tree.pyx | 105 |
1 files changed, 100 insertions, 5 deletions
diff --git a/src/python/gudhi/simplex_tree.pyx b/src/python/gudhi/simplex_tree.pyx index 05bfe22e..4cf176f5 100644 --- a/src/python/gudhi/simplex_tree.pyx +++ b/src/python/gudhi/simplex_tree.pyx @@ -8,14 +8,24 @@ # - YYYY/MM Author: Description of the modification from cython.operator import dereference, preincrement -from libc.stdint cimport intptr_t +from libc.stdint cimport intptr_t, int32_t, int64_t import numpy as np cimport gudhi.simplex_tree +cimport cython +from numpy.math cimport INFINITY __author__ = "Vincent Rouvreau" __copyright__ = "Copyright (C) 2016 Inria" __license__ = "MIT" +ctypedef fused some_int: + int32_t + int64_t + +ctypedef fused some_float: + float + double + cdef bool callback(vector[int] simplex, void *blocker_func): return (<object>blocker_func)(simplex) @@ -228,6 +238,91 @@ cdef class SimplexTree: """ return self.get_ptr().insert(simplex, <double>filtration) + @staticmethod + @cython.boundscheck(False) + def create_from_array(filtrations, double max_filtration=INFINITY): + """Creates a new, empty complex and inserts vertices and edges. The vertices are numbered from 0 to n-1, and + the filtration values are encoded in the array, with the diagonal representing the vertices. It is the + caller's responsibility to ensure that this defines a filtration, which can be achieved with either:: + + filtrations[np.diag_indices_from(filtrations)] = filtrations.min(axis=1) + + or:: + + diag = filtrations.diagonal() + filtrations = np.fmax(np.fmax(filtrations, diag[:, None]), diag[None, :]) + + :param filtrations: the filtration values of the vertices and edges to insert. The matrix is assumed to be symmetric. + :type filtrations: numpy.ndarray of shape (n,n) + :param max_filtration: only insert vertices and edges with filtration values no larger than max_filtration + :type max_filtration: float + :returns: the new complex + :rtype: SimplexTree + """ + # TODO: document which half of the matrix is actually read? + filtrations = np.asanyarray(filtrations, dtype=float) + cdef double[:,:] F = filtrations + ret = SimplexTree() + cdef int n = F.shape[0] + assert n == F.shape[1], 'create_from_array() expects a square array' + with nogil: + ret.get_ptr().insert_matrix(&F[0,0], n, F.strides[0], F.strides[1], max_filtration) + return ret + + def insert_edges_from_coo_matrix(self, edges): + """Inserts edges given by a sparse matrix in `COOrdinate format + <https://docs.scipy.org/doc/scipy/reference/generated/scipy.sparse.coo_matrix.html>`_. + If an edge is repeated, the smallest filtration value is used. Missing entries are not inserted. + Diagonal entries are currently interpreted as vertices, although we do not guarantee this behavior + in the future, and this is only useful if you want to insert vertices with a smaller filtration value + than the smallest edge containing it, since vertices are implicitly inserted together with the edges. + + :param edges: the edges to insert and their filtration values. + :type edges: scipy.sparse.coo_matrix of shape (n,n) + + .. seealso:: :func:`insert_batch` + """ + # Without this, it could be slow if we end up inserting vertices in a bad order (flat_map). + self.get_ptr().insert_batch_vertices(np.unique(np.stack((edges.row, edges.col))), INFINITY) + # TODO: optimize this? + for edge in zip(edges.row, edges.col, edges.data): + self.get_ptr().insert((edge[0], edge[1]), edge[2]) + + @cython.boundscheck(False) + @cython.wraparound(False) + def insert_batch(self, some_int[:,:] vertex_array, some_float[:] filtrations): + """Inserts k-simplices given by a sparse array in a format similar + to `torch.sparse <https://pytorch.org/docs/stable/sparse.html>`_. + The n-th simplex has vertices `vertex_array[0,n]`, ..., + `vertex_array[k,n]` and filtration value `filtrations[n]`. + If a simplex is repeated, the smallest filtration value is used. + Simplices with a repeated vertex are currently interpreted as lower + dimensional simplices, but we do not guarantee this behavior in the + future. Any time a simplex is inserted, its faces are inserted as well + if needed to preserve a simplicial complex. + + :param vertex_array: the k-simplices to insert. + :type vertex_array: numpy.array of shape (k+1,n) + :param filtrations: the filtration values. + :type filtrations: numpy.array of shape (n,) + """ + cdef vector[int] vertices = np.unique(vertex_array) + cdef Py_ssize_t k = vertex_array.shape[0] + cdef Py_ssize_t n = vertex_array.shape[1] + assert filtrations.shape[0] == n, 'inconsistent sizes for vertex_array and filtrations' + cdef Py_ssize_t i + cdef Py_ssize_t j + cdef vector[int] v + with nogil: + # Without this, it could be slow if we end up inserting vertices in a bad order (flat_map). + # NaN currently does the wrong thing + self.get_ptr().insert_batch_vertices(vertices, INFINITY) + for i in range(n): + for j in range(k): + v.push_back(vertex_array[j, i]) + self.get_ptr().insert(v, filtrations[i]) + v.clear() + def get_simplices(self): """This function returns a generator with simplices and their given filtration values. @@ -376,7 +471,7 @@ cdef class SimplexTree: """ return self.get_ptr().prune_above_filtration(filtration) - def expansion(self, max_dim): + def expansion(self, max_dimension): """Expands the simplex tree containing only its one skeleton until dimension max_dim. @@ -390,10 +485,10 @@ cdef class SimplexTree: The simplex tree must contain no simplex of dimension bigger than 1 when calling the method. - :param max_dim: The maximal dimension. - :type max_dim: int + :param max_dimension: The maximal dimension. + :type max_dimension: int """ - cdef int maxdim = max_dim + cdef int maxdim = max_dimension with nogil: self.get_ptr().expansion(maxdim) |