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Diffstat (limited to 'src/python/gudhi/alpha_complex.pyx')
| -rw-r--r-- | src/python/gudhi/alpha_complex.pyx | 137 |
1 files changed, 89 insertions, 48 deletions
diff --git a/src/python/gudhi/alpha_complex.pyx b/src/python/gudhi/alpha_complex.pyx index d75e374a..375e1561 100644 --- a/src/python/gudhi/alpha_complex.pyx +++ b/src/python/gudhi/alpha_complex.pyx @@ -16,10 +16,11 @@ from libcpp.utility cimport pair from libcpp.string cimport string from libcpp cimport bool from libc.stdint cimport intptr_t -import os +import warnings from gudhi.simplex_tree cimport * from gudhi.simplex_tree import SimplexTree +from gudhi import read_points_from_off_file __author__ = "Vincent Rouvreau" __copyright__ = "Copyright (C) 2016 Inria" @@ -27,97 +28,137 @@ __license__ = "GPL v3" cdef extern from "Alpha_complex_interface.h" namespace "Gudhi": cdef cppclass Alpha_complex_interface "Gudhi::alpha_complex::Alpha_complex_interface": - Alpha_complex_interface(vector[vector[double]] points) nogil except + - # bool from_file is a workaround for cython to find the correct signature - Alpha_complex_interface(string off_file, bool from_file) nogil except + + Alpha_complex_interface(vector[vector[double]] points, vector[double] weights, bool fast_version, bool exact_version) nogil except + vector[double] get_point(int vertex) nogil except + - void create_simplex_tree(Simplex_tree_interface_full_featured* simplex_tree, double max_alpha_square) nogil except + + void create_simplex_tree(Simplex_tree_interface_full_featured* simplex_tree, double max_alpha_square, bool default_filtration_value) nogil except + + @staticmethod + void set_float_relative_precision(double precision) nogil + @staticmethod + double get_float_relative_precision() nogil # AlphaComplex python interface cdef class AlphaComplex: - """AlphaComplex is a simplicial complex constructed from the finite cells - of a Delaunay Triangulation. + """AlphaComplex is a simplicial complex constructed from the finite cells of a Delaunay Triangulation. - The filtration value of each simplex is computed as the square of the - circumradius of the simplex if the circumsphere is empty (the simplex is - then said to be Gabriel), and as the minimum of the filtration values of - the codimension 1 cofaces that make it not Gabriel otherwise. + The filtration value of each simplex is computed as the square of the circumradius of the simplex if the + circumsphere is empty (the simplex is then said to be Gabriel), and as the minimum of the filtration values of the + codimension 1 cofaces that make it not Gabriel otherwise. - All simplices that have a filtration value strictly greater than a given - alpha squared value are not inserted into the complex. + All simplices that have a filtration value strictly greater than a given alpha squared value are not inserted into + the complex. .. note:: - When Alpha_complex is constructed with an infinite value of alpha, the - complex is a Delaunay complex. - + When Alpha_complex is constructed with an infinite value of alpha, the complex is a Delaunay complex. """ - cdef Alpha_complex_interface * thisptr + cdef Alpha_complex_interface * this_ptr # Fake constructor that does nothing but documenting the constructor - def __init__(self, points=None, off_file=''): + def __init__(self, points=[], off_file='', weights=None, precision='safe'): """AlphaComplex constructor. :param points: A list of points in d-Dimension. - :type points: list of list of double - - Or + :type points: Iterable[Iterable[float]] - :param off_file: An OFF file style name. + :param off_file: **[deprecated]** An `OFF file style <fileformats.html#off-file-format>`_ name. + If an `off_file` is given with `points` as arguments, only points from the file are taken into account. :type off_file: string + + :param weights: A list of weights. If set, the number of weights must correspond to the number of points. + :type weights: Iterable[float] + + :param precision: Alpha complex precision can be 'fast', 'safe' or 'exact'. Default is 'safe'. + :type precision: string + + :raises FileNotFoundError: **[deprecated]** If `off_file` is set but not found. + :raises ValueError: In case of inconsistency between the number of points and weights. """ # The real cython constructor - def __cinit__(self, points = None, off_file = ''): - cdef vector[vector[double]] pts + def __cinit__(self, points = [], off_file = '', weights=None, precision = 'safe'): + assert precision in ['fast', 'safe', 'exact'], "Alpha complex precision can only be 'fast', 'safe' or 'exact'" + cdef bool fast = precision == 'fast' + cdef bool exact = precision == 'exact' + if off_file: - if os.path.isfile(off_file): - self.thisptr = new Alpha_complex_interface( - off_file.encode('utf-8'), True) - else: - print("file " + off_file + " not found.") - else: - if points is None: - # Empty Alpha construction - points=[] - pts = points - with nogil: - self.thisptr = new Alpha_complex_interface(pts) - + warnings.warn("off_file is a deprecated parameter, please consider using gudhi.read_points_from_off_file", + DeprecationWarning) + points = read_points_from_off_file(off_file = off_file) + + # weights are set but is inconsistent with the number of points + if weights != None and len(weights) != len(points): + raise ValueError("Inconsistency between the number of points and weights") + + # need to copy the points to use them without the gil + cdef vector[vector[double]] pts + cdef vector[double] wgts + pts = points + if weights != None: + wgts = weights + with nogil: + self.this_ptr = new Alpha_complex_interface(pts, wgts, fast, exact) def __dealloc__(self): - if self.thisptr != NULL: - del self.thisptr + if self.this_ptr != NULL: + del self.this_ptr def __is_defined(self): """Returns true if AlphaComplex pointer is not NULL. """ - return self.thisptr != NULL + return self.this_ptr != NULL def get_point(self, vertex): - """This function returns the point corresponding to a given vertex. + """This function returns the point corresponding to a given vertex from the :class:`~gudhi.SimplexTree`. :param vertex: The vertex. :type vertex: int :rtype: list of float :returns: the point. """ - return self.thisptr.get_point(vertex) + return self.this_ptr.get_point(vertex) - def create_simplex_tree(self, max_alpha_square = float('inf')): + def create_simplex_tree(self, max_alpha_square = float('inf'), default_filtration_value = False): """ - :param max_alpha_square: The maximum alpha square threshold the - simplices shall not exceed. Default is set to infinity, and - there is very little point using anything else since it does - not save time. + :param max_alpha_square: The maximum alpha square threshold the simplices shall not exceed. Default is set to + infinity, and there is very little point using anything else since it does not save time. :type max_alpha_square: float + :param default_filtration_value: Set this value to `True` if filtration values are not needed to be computed + (will be set to `NaN`). Default value is `False` (which means compute the filtration values). + :type default_filtration_value: bool :returns: A simplex tree created from the Delaunay Triangulation. :rtype: SimplexTree """ stree = SimplexTree() cdef double mas = max_alpha_square cdef intptr_t stree_int_ptr=stree.thisptr + cdef bool compute_filtration = default_filtration_value == True with nogil: - self.thisptr.create_simplex_tree(<Simplex_tree_interface_full_featured*>stree_int_ptr, mas) + self.this_ptr.create_simplex_tree(<Simplex_tree_interface_full_featured*>stree_int_ptr, + mas, compute_filtration) return stree + + @staticmethod + def set_float_relative_precision(precision): + """ + :param precision: When the AlphaComplex is constructed with :code:`precision = 'safe'` (the default), + one can set the float relative precision of filtration values computed in + :func:`~gudhi.AlphaComplex.create_simplex_tree`. + Default is :code:`1e-5` (cf. :func:`~gudhi.AlphaComplex.get_float_relative_precision`). + For more details, please refer to + `CGAL::Lazy_exact_nt<NT>::set_relative_precision_of_to_double <https://doc.cgal.org/latest/Number_types/classCGAL_1_1Lazy__exact__nt.html>`_ + :type precision: float + """ + if precision <=0. or precision >= 1.: + raise ValueError("Relative precision value must be strictly greater than 0 and strictly lower than 1") + Alpha_complex_interface.set_float_relative_precision(precision) + + @staticmethod + def get_float_relative_precision(): + """ + :returns: The float relative precision of filtration values computation in + :func:`~gudhi.AlphaComplex.create_simplex_tree` when the AlphaComplex is constructed with + :code:`precision = 'safe'` (the default). + :rtype: float + """ + return Alpha_complex_interface.get_float_relative_precision() |