ddg.indexedfaceset package

Module contents

ddg.indexedfaceset.arrow(resolution=20, heights=(0, 0.7, 0.7, 1), radii=(0.05, 0.05, 0.125), co_attr='co')[source]

Create an arrow as an indexed face set.

This is useful to visualise vectors.

By default, the arrow will point up. The bottom will be at (0, 0, 0) and the tip at (0, 0, 1).

Parameters:

resolutionint (default=20): The amount of vertices at the base of the tip
heightsfloat sequence of length 4 (default=(0, 0.7, 0.7, 1)): First element defines height of the bottom of the stick, the second the height of the top of the stick, the third the height of the base of the head and the fourth the height of the tip.
radiifloat sequence of length 3 (default=(0.05, 0.05, 0.125)): First element defines the radius of the bottom of the stick, second the radius of the top of the stick and the third the radius of the base of the tip.
co_attrstr or None (default=”co”): Name of the vertex attribute that stores the coordinates. If co_attr=None, don’t assign any coordinates.

Returns:

objddg.indexedfaceset.IndexedFaceSet: An arrow.

ddg.indexedfaceset.cone(resolution=20, fill_caps=True, radius=1, length=1, center=(0, 0, 0), normal=(0, 0, 1), co_attr='co')[source]

Create a cone as an indexed face set.

By default, the cone’s base will be at (0, 0, 0) and its tip at (0, 0, 1).

Parameters:

resolutionint (default=20): The number of vertices of the base.
fill_caps: bool (default=True): If True, include the face of the base.
radiusfloat (default=1): The radius of the base of the cone.
lengthfloat (default=1): The length of the cone.
centerarray_like of shape (3,) (default=(0, 0, 0)): The center of the base of the cone.
normalarray_like of shape (3,) (default=(0, 0, 1)): The normal of the cone’s base face.
co_attrstr or None (default=”co”): Name of the vertex attribute that stores the coordinates. If co_attr=None, don’t assign any coordinates.

Returns:

objddg.indexedfaceset.IndexedFaceSet: A cone.

ddg.indexedfaceset.cube(co_attr='co')[source]

Create a cube as an indexed face set

By default, standard coordinates of a unit cube, centered at (0, 0, 0), will be assigned to the vertices.

Parameters:

co_attrstr or None (default=”co”): Name of the vertex attribute that stores the coordinates. If co_attr=None, don’t assign any coordinates.

Returns:

objddg.indexedfaceset.IndexedFaceSet: A cube.

ddg.indexedfaceset.cylinder(resolution=20, fill_caps=True, top_radius=1, bot_radius=1, length=1, center=(0, 0, 0), normal=(0, 0, 1), co_attr='co')[source]

Create a cylinder as an indexed face set.

By default, the cylinder’s bottom will be at (0, 0, 0) and its top at (0, 0, 1).

Parameters:

resolutionint (default=20): The number of vertices on each side.
fill_capsbool (default=True): If True, include the faces of the bottom and the top.
top_radiusfloat (default=1): The radius of the top of the cylinder.
bot_radiusfloat (default=1): The radius of the bottom of the cylinder
lengthfloat (default=1): The length of the cylinder.
centerarray_like of shape (3,) (default=(0, 0, 0)): The center of the bottom of the cylinder.
normalarray_like of shape (3,) (default=(0, 0, 1)): The normal of the cylinder’s top and bottom faces.
co_attrstr or None (default=”co”): Name of the vertex attribute that stores the coordinates. If co_attr=None, don’t assign any coordinates.

Returns:

objddg.indexedfaceset.IndexedFaceSet: A cylinder.

ddg.indexedfaceset.disc(resolution=20, center=(0, 0, 0), normal=(0, 0, 1), radius=1, co_attr='co')[source]

Create a disc as an indexed face set.

By default, the disc is centered at (0, 0, 0), the normal is (0, 0, 1) and the radius is 1.

Parameters:

resolutionint (default=20): The amount of vertices of the disc
centerarray_like of shape (3,) (default=(0, 0, 0)): The center of the disc as a list in 3D space.
normalarray_like of shape (3,) (default=(0, 0, 1)): The normal vector of the disc.
radiusfloat (default=1): The radius of the disc.
co_attrstr or None (default=”co”): Name of the vertex attribute that stores the coordinates. If co_attr=None, don’t assign any coordinates.

Returns:

objddg.indexedfaceset.IndexedFaceSet: A disc.

ddg.indexedfaceset.dodecahedron(co_attr='co')[source]

Create a dodecahedron as an indexed face set.

By default, standard coordinates of a unit dodecahedron, centered at (0, 0, 0), will be assigned to the vertices.

Parameters:

co_attrstr or None (default=”co”): Name of the vertex attribute that stores the coordinates. If co_attr=None, don’t assign any coordinates.

Returns:

objddg.indexedfaceset.IndexedFaceSet: A dodecahedron.

ddg.indexedfaceset.grid(shape, co_attr='co')[source]

Create a quad grid as an indexed face set.

The shape defines the number of vertices in each direction. Both 2D and 3D grids are supported.

Parameters:

shapetuple of length 2 or 3: Shape of the grid. The first entry is the number of vertices in the x-direction, the second the number of vertices in the y-direction and the third (if given) the number of vertices in the z-direction.
co_attrstr or None (default=”co”): Name of the vertex attribute that stores the coordinates. If co_attr=None, don’t assign any coordinates.

Returns:

objddg.indexedfaceset.IndexedFaceSet: A quad grid.

Examples

>>> import ddg
>>> quad_grid = ddg.indexedfaceset.grid((2, 3))
>>> quad_grid.vertex_attributes["co"]
array([[0, 0],
       [1, 0],
       [0, 1],
       [1, 1],
       [0, 2],
       [1, 2]])

>>> quad_grid = ddg.indexedfaceset.grid((2, 3, 1))
>>> quad_grid.vertex_attributes["co"]
array([[0, 0, 0],
       [1, 0, 0],
       [0, 1, 0],
       [1, 1, 0],
       [0, 2, 0],
       [1, 2, 0]])

>>> quad_grid = ddg.indexedfaceset.grid((2, 3, 2))
>>> quad_grid.vertex_attributes["co"]
array([[0, 0, 0],
       [1, 0, 0],
       [0, 1, 0],
       [1, 1, 0],
       [0, 2, 0],
       [1, 2, 0],
       [0, 0, 1],
       [1, 0, 1],
       [0, 1, 1],
       [1, 1, 1],
       [0, 2, 1],
       [1, 2, 1]])

ddg.indexedfaceset.icosahedron(co_attr='co')[source]

Create an icosahedron as an indexed face set.

By default, standard coordinates of a unit icosahedron, centered at (0, 0, 0), will be assigned to the vertices.

Parameters:

co_attrstr or None (default=”co”): Name of the vertex attribute that stores the coordinates. If co_attr=None, don’t assign any coordinates.

Returns:

objddg.indexedfaceset.IndexedFaceSet: An icosahedron.

ddg.indexedfaceset.octahedron(co_attr='co')[source]

Create an octahedron as an indexed face set.

By default, standard coordinates of a unit octahedron, centered at (0, 0, 0), will be assigned to the vertices.

Parameters:

co_attrstr or None (default=”co”): Name of the vertex attribute that stores the coordinates. If co_attr=None, don’t assign any coordinates.

Returns:

objddg.indexedfaceset.IndexedFaceSet: An octahedron.

ddg.indexedfaceset.tetrahedron(co_attr='co')[source]

Create a tetrahedron as an indexed face set.

By default, standard coordinates of a unit tetrahedron, centered at (0, 0, 0), will be assigned to the vertices.

Parameters:

co_attrstr or None (default=”co”): Name of the vertex attribute that stores the coordinates. If co_attr=None, don’t assign any coordinates.

Returns:

objddg.indexedfaceset.IndexedFaceSet: A tetrahedron.

ddg.indexedfaceset.triangle_grid(shape, co_attr='co')[source]

Create a triangle grid as an indexed face set.

The shape defines the number of vertices in each direction. Currently only supports 2D grids and planar grids in 3D.

Parameters:

shapetuple of length 2 or 3: Shape of the grid. The first entry is the number of vertices in the x-direction, the second the number of vertices in the y-direction and the third (if given) the number of vertices in the z-direction.
co_attrstr or None (default=”co”): Name of the vertex attribute that stores the coordinates. If co_attr=None, don’t assign any coordinates.

Returns:

objddg.indexedfaceset.IndexedFaceSet: A triangle grid.

Examples

>>> import ddg
>>> tri_grid = ddg.indexedfaceset.triangle_grid((2, 3))
>>> tri_grid.vertex_attributes["co"]
array([[0, 0],
       [2, 0],
       [1, 2],
       [3, 2],
       [2, 4],
       [4, 4]])

>>> tri_grid = triangle_grid((2, 3, 1))
>>> tri_grid.vertex_attributes["co"]
array([[0, 0, 0],
       [2, 0, 0],
       [1, 2, 0],
       [3, 2, 0],
       [2, 4, 0],
       [4, 4, 0]])

ddg.indexedfaceset.grid_with_periodicity(shape, periodicity=(0, 0), co_attr='co')[source]

Create a quad grid with a periodicity as an indexed face set.

A quad grid with periodicity (0, 0) is the box in Z^2 with lower-left corner (0, 0) and upper-right corner (shape[0] - 1, shape[1] - 1). In other words, the vertices are (i_0, i_1) with 0 <= i_0 <= shape[0] - 1 and 0 <= i_1 <= shape[1] - 1. A quad grid with periodicity not equal to (0, 0) is obtained from the quad grid with periodicity (0, 0) by gluing the boundary edges as described in the table below.

Parameters:

shapetuple of length 2

Shape of the grid. The first entry is the number of vertices in the x-direction, the second the number of vertices in the y-direction.

periodicitytuple of length 2 (default=(0,0))

The periodicity of the grid. This is only meaningful in case of 2D grid. For 3D shape this attribute doesn’t have any effect.

Periodicity	Topology	Gluing Axis
(0, 0)	Disk	None
(1, 0)	Cylinder	along the first axis
(0, 1)	Cylinder	along the second axis
(1, 1)	Torus	along both axes
(-1, 0)	Moebius Band	along the first axis in reversed orientation
(0, -1)	Moebius Band	along the second axis in reversed orientation

co_attrstr or None (default=”co”)

Name of the vertex attribute that stores the coordinates. If co_attr=None, don’t assign any coordinates.

Returns:

objddg.indexedfaceset.IndexedFaceSet: A quad grid.

Examples

>>> import ddg
>>> grid = ddg.indexedfaceset.grid_with_periodicity((2, 3), periodicity=(1, 0))
>>> grid.face_list()
[(0, 1, 3, 2), (2, 3, 5, 4), (0, 1, 3, 2), (2, 3, 5, 4)]
>>> grid.vertex_attributes["co"]
array([[ 1.0000000e+00,  0.0000000e+00,  0.0000000e+00],
       [-1.0000000e+00,  0.0000000e+00,  1.2246468e-16],
       [ 1.0000000e+00,  1.0000000e+00,  0.0000000e+00],
       [-1.0000000e+00,  1.0000000e+00,  1.2246468e-16],
       [ 1.0000000e+00,  2.0000000e+00,  0.0000000e+00],
       [-1.0000000e+00,  2.0000000e+00,  1.2246468e-16]])

exception ddg.indexedfaceset.BoundaryException[source]

Bases: Exception

args

with_traceback(): Exception.with_traceback(tb) – set self.__traceback__ to tb and return self.

exception ddg.indexedfaceset.NonManifoldException[source]

Bases: Exception

args

with_traceback(): Exception.with_traceback(tb) – set self.__traceback__ to tb and return self.

exception ddg.indexedfaceset.NonOrientableException[source]

Bases: Exception

args

with_traceback(): Exception.with_traceback(tb) – set self.__traceback__ to tb and return self.

ddg.indexedfaceset.diags_from_faces(faces)[source]

Calculates diagonals of the faces of a quadrilateral mesh.

Parameters:

facesnp.ndarray: Array of faces In case only one face exists, it should be passed as a 2D array

Returns:

tuple: a tuple of 2d array of two sets of diagonals of the quads

ddg.indexedfaceset.face_boundary(face)[source]

ddg.indexedfaceset.indexed_face_set_to_surface(ifs, vertex_index_attribute='ifs_index', face_index_attribute='ifs_face_index')[source]: Convert an indexed face set to a half edge data structure. If the indexed face set can not be converted an empty half edge data structure is returned.

ddg.indexedfaceset.is_manifold(ifs)[source]: Returns whether every edge of the non oriented indexed face set is contained in at most two faces.

ddg.indexedfaceset.orient(src_ifs, face_map={})[source]: Try to orient a given indexed face set. Raises Value Error if the given set is not orientable.

class ddg.indexedfaceset.GeneralizedIndexedFaceSet(faces=[])[source]

Bases: object

Implementation of a combinatorial indexed face set data structure with a list of faces and some utility functions.

Parameters:

faces: list: List of face tuples that will generate the indexed face set.

get_vertex_set()[source]: Returns the set of vertices of an indexed face set

set_attribute(attr_name, cell_type, attribute, cell_subset=None)[source]

Method to add attributes to cells of an ifs. If the attribute already exists, it changes it. If only a subset is specified, it only updates the subset values.

Parameters:

cell_type: str: Type of cell to which the attribute must be added
attr_namestr: Name of the attribute
attributeSubscriptable object: A subscriptable object of the attributes to be assigned to each vertex
cell_subset: set or list depending on the cell type: if the cells in question are not the whole cells of the ifs but a subset of it, they must be given as input in this parameter

Returns:

dict: A nested dictionary of all attributes of vertices

delete_attribute(attr_name, cell_type)[source]

Deletes the attribute given by its name

Parameters:

attr_namestr: Name of the attribute
cell_type: str: Type of cell to which the attribute must be added

get_attribute(attr_name, cell_type, cell)[source]

get cell attribute

Parameters:

attr_namestr: Name of the attribute. Represents keys for the attribute dictionaries
cell_typestr: Type of cell from which the attribute is to be retrieved
cellfloat or int for verts, tuples for edges and faces: The cell to which the attribute is assigned. Type depends on the type of the inputs given to create the class.

Returns:

The attribute in the specified position. Type depends on the attribute type.

adjacent_faces_with_orientation(edge)[source]

Get a list of oriented faces adjacent to an given edge.

The resulting faces are of the class OrientedFace with self.orientation = 1 if they contain the edge in the given orientation or self.orientation = -1 if they contain the edge in reversed orientation.

Parameters:

edgetuple: Tuple of two integers.

Returns:

list: List of instances of the class OrientedFace that are adjacent to the input edge.

adjacent_faces(edge)[source]

Get a list of faces, i.e. tuples adjacent to an given edge.

Parameters:

edgetuple: Tuple of two integers.

Returns:

list: List of tuples that represent all adjacent faces despite of orientation.

opposite_face(face, edge)[source]

Get the other face adjacent to a given edge of a face.

If the edge is adjacent to only one or more than two faces return None.

Parameters:

edgetuple: Tuple of two integers.
facetuple: The input face incuding the edge from which the other face will be determined.

Returns:

tuple: The other face incident to the given edge.
None: If edge is adjacent to only one or more than two faces.

opposite_face_with_orientation(face, edge)[source]

Get the other oriented face adjacent to a given edge of a face.

If the edge is adjacent to only one or more than two faces return None.

Parameters:

edgetuple: Tuple of two integers.
facetuple: The input face incuding the edge from which the other face will be determined.

Returns:

OrientedFace: The other face incident to the given edge.
NoneFace: If edge is adjacent to only one or more than two faces.

neighboring_faces(face)[source]

Get all faces that are adjacent to a given a face.

If an edge has none or more than one other neighbouring faces, None will be returned.

Parameters:

facetuple: The input face whose neighbouring faces will be determined.

Returns:

list

List of neighbouring faces in cyclic order. ..

Includes ..

tuple ..

If there exist exactly one neighbouring face to an edge. ..

None ..

If edge is adjacent to only one or more than two faces. ..

neighboring_faces_with_orientation(face)[source]

Get all oriented faces that are adjacent to a given a face.

If an edge has none or more than one other neighbouring faces, None will be returned.

Parameters:

facetuple: The input face whose neighbouring faces will be determined.

Returns:

list

List of neighbouring faces in cyclic order. ..

Includes ..

OrientedFace ..

If there exist exactly one neighbouring face to an edge. ..

NoneFace ..

If edge is adjacent to only one or more than two faces. ..

face_list()[source]

Get all faces of the indexed face set.

Returns:

list: List of tuples representing the faces of the indexed face set.

number_of_faces()[source]

Get the number of faces of the indexed face set.

Returns:

int: Number of faces of the indexed face set.

edge_set()[source]

Get all edges of the indexed face set.

Returns:

set: Unordered set of tuples of two integers representing all edges.

face_boundary(face)[source]

Returns a set of edges bounding the face.

The edges are tuples orded by the orientation of the face.

Parameters:

facetuple: The face to be investigated.

Returns:

tuple: tuple with ordered edge tuples

Examples

>>> from ddg.indexedfaceset import GeneralizedIndexedFaceSet
>>> faceSet = GeneralizedIndexedFaceSet([(1, 2, 4), (2, 3, 4)])
>>> faceSet.face_boundary((1, 2, 4))
((1, 2), (2, 4), (4, 1))

add_face(face)[source]

Adds face to the indexed face set.

Simply adds the face without paying attention to the maifold property.

Parameters:

facetuple: The face to be investigated.

class ddg.indexedfaceset.IndexedFaceSet(faces=[])[source]

Bases: GeneralizedIndexedFaceSet

An indexed face set whose vertices must be integers of indices 0 to n-1 only. The attributes of cells for this class are also restricted to numpy arrays only.

cell_index(cell_type, cell)[source]

Method to get the index of the given cell. Vertices are already indices. Mostly used to get the cell of edges and faces

Parameters:

cell_typestr: type of cells to be indiced. “verts”, “edges” or “faces” are the proper values.
cellint for verts, tuples for edges and faces: the cell to be indiced.

Returns:

The index of the cell

get_attribute(attr_name, cell_type, cell)[source]

‘Get’ method corresponding the attribute structure of the subclass to override the same method in the parent class

Parameters:

cell_typestr: Type of cell from which the attribute are to be recalled
cell_typestr: Type of cell from which the attribute is to be retrieved
cellint for verts, int or tuples for edges and faces: The cell or its index. For vertices, these two are the same. For edges and faces these are different. Both form are accepted.

Returns:

numpy.ndarray: The attribute in the specified position.

set_attribute(attr_name, cell_type, attribute, dtype=<class 'float'>)[source]

Method to create a dictionary of attributes for a given cell type.

Parameters:

attr_namestr: Name of the attribute to get in string
attributenp.ndarray: An array of the attributes to be set

Returns:

Attribute dictionary

edge_vertex_list(vertex_index)[source]

Method to find the edges which share a specific vertex.

Parameters:

vertex_indexint: The index of the vertex to be found (0,…, n-1)

Returns:

numpy.ndarray: 2D array of edges as tuples

face_vertex_list(vertex_index)[source]

Method to find the faces which share a specific vertex

Parameters:

vertex_indexint: The index of the vertex to be found (0,…, n-1)

Returns:

numpy.ndarray: returns indices of faces

face_vertex_dict(vertex_index)[source]

Method to create a dictionary which has as values the arrays of faces with which they share a specific vertex and as keys the number of edges of the faces

Parameters:

vertex_indexint: The index of the vertex to be found (0,…, n-1)

Returns:

dict: Keys : the number of edges of faces Values : thoses faces with the key number of edges which share the input vertex

face_edge_list(edge_index)[source]

Method to find the faces which share a specific edge

Parameters:

edge_indexint: The index of the edge

Returns:

numpy.ndarray: For non-uniform meshes the return value is a 1D array of faces as tuples For uniform meshes the return value is a 2D array

is_boundary_vertex(vertex_index)[source]

checks if a vertex is a boundary vertex or not

Parameters:

vertex_index1D list or array: the index of the vertex in question

Returns:

True if the the vertex is a boundary vertex, otherwise False

property boundary_vertices: Method to create a set of boundary vertices of the ifs

add_face(face)

Adds face to the indexed face set.

Simply adds the face without paying attention to the maifold property.

Parameters:

facetuple: The face to be investigated.

adjacent_faces(edge)

Get a list of faces, i.e. tuples adjacent to an given edge.

Parameters:

edgetuple: Tuple of two integers.

Returns:

list: List of tuples that represent all adjacent faces despite of orientation.

adjacent_faces_with_orientation(edge)

Get a list of oriented faces adjacent to an given edge.

The resulting faces are of the class OrientedFace with self.orientation = 1 if they contain the edge in the given orientation or self.orientation = -1 if they contain the edge in reversed orientation.

Parameters:

edgetuple: Tuple of two integers.

Returns:

list: List of instances of the class OrientedFace that are adjacent to the input edge.

delete_attribute(attr_name, cell_type)

Deletes the attribute given by its name

Parameters:

attr_namestr: Name of the attribute
cell_type: str: Type of cell to which the attribute must be added

edge_set()

Get all edges of the indexed face set.

Returns:

set: Unordered set of tuples of two integers representing all edges.

face_boundary(face)

Returns a set of edges bounding the face.

The edges are tuples orded by the orientation of the face.

Parameters:

facetuple: The face to be investigated.

Returns:

tuple: tuple with ordered edge tuples

Examples

>>> from ddg.indexedfaceset import GeneralizedIndexedFaceSet
>>> faceSet = GeneralizedIndexedFaceSet([(1, 2, 4), (2, 3, 4)])
>>> faceSet.face_boundary((1, 2, 4))
((1, 2), (2, 4), (4, 1))

face_list()

Get all faces of the indexed face set.

Returns:

list: List of tuples representing the faces of the indexed face set.

get_vertex_set(): Returns the set of vertices of an indexed face set

neighboring_faces(face)

Get all faces that are adjacent to a given a face.

If an edge has none or more than one other neighbouring faces, None will be returned.

Parameters:

facetuple: The input face whose neighbouring faces will be determined.

Returns:

list

List of neighbouring faces in cyclic order. ..

Includes ..

tuple ..

If there exist exactly one neighbouring face to an edge. ..

None ..

If edge is adjacent to only one or more than two faces. ..

neighboring_faces_with_orientation(face)

Get all oriented faces that are adjacent to a given a face.

If an edge has none or more than one other neighbouring faces, None will be returned.

Parameters:

facetuple: The input face whose neighbouring faces will be determined.

Returns:

list

List of neighbouring faces in cyclic order. ..

Includes ..

OrientedFace ..

If there exist exactly one neighbouring face to an edge. ..

NoneFace ..

If edge is adjacent to only one or more than two faces. ..

number_of_faces()

Get the number of faces of the indexed face set.

Returns:

int: Number of faces of the indexed face set.

opposite_face(face, edge)

Get the other face adjacent to a given edge of a face.

If the edge is adjacent to only one or more than two faces return None.

Parameters:

edgetuple: Tuple of two integers.
facetuple: The input face incuding the edge from which the other face will be determined.

Returns:

tuple: The other face incident to the given edge.
None: If edge is adjacent to only one or more than two faces.

opposite_face_with_orientation(face, edge)

Get the other oriented face adjacent to a given edge of a face.

If the edge is adjacent to only one or more than two faces return None.

Parameters:

edgetuple: Tuple of two integers.
facetuple: The input face incuding the edge from which the other face will be determined.

Returns:

OrientedFace: The other face incident to the given edge.
NoneFace: If edge is adjacent to only one or more than two faces.

class ddg.indexedfaceset.NgonalIndexedFaceSet(faces=array([], dtype=float64))[source]

Bases: IndexedFaceSet

An indexed face set whose faces are of constant valency of k.

face_vertex_array(vertex_index)[source]

Method to find the faces which share a specific vertex. Overrides the method in parent class.

Parameters:

vertex_indexint: The index of the vertex to be found (0,…, n-1)

Returns:

numpy.ndarray: returns indices of faces

face_vertex_incidence()[source]

Method to create the valencies.

Returns:

list: the list of valencies in the same order of vertex index

face_edge_incidence()[source]

Method to create the valency for edge-face.

Returns:

list: the list of face-edge-valency in the same order of edge index

add_face(face)

Adds face to the indexed face set.

Simply adds the face without paying attention to the maifold property.

Parameters:

facetuple: The face to be investigated.

adjacent_faces(edge)

Get a list of faces, i.e. tuples adjacent to an given edge.

Parameters:

edgetuple: Tuple of two integers.

Returns:

list: List of tuples that represent all adjacent faces despite of orientation.

adjacent_faces_with_orientation(edge)

Get a list of oriented faces adjacent to an given edge.

The resulting faces are of the class OrientedFace with self.orientation = 1 if they contain the edge in the given orientation or self.orientation = -1 if they contain the edge in reversed orientation.

Parameters:

edgetuple: Tuple of two integers.

Returns:

list: List of instances of the class OrientedFace that are adjacent to the input edge.

property boundary_vertices: Method to create a set of boundary vertices of the ifs

cell_index(cell_type, cell)

Method to get the index of the given cell. Vertices are already indices. Mostly used to get the cell of edges and faces

Parameters:

cell_typestr: type of cells to be indiced. “verts”, “edges” or “faces” are the proper values.
cellint for verts, tuples for edges and faces: the cell to be indiced.

Returns:

The index of the cell

delete_attribute(attr_name, cell_type)

Deletes the attribute given by its name

Parameters:

attr_namestr: Name of the attribute
cell_type: str: Type of cell to which the attribute must be added

edge_set()

Get all edges of the indexed face set.

Returns:

set: Unordered set of tuples of two integers representing all edges.

edge_vertex_list(vertex_index)

Method to find the edges which share a specific vertex.

Parameters:

vertex_indexint: The index of the vertex to be found (0,…, n-1)

Returns:

numpy.ndarray: 2D array of edges as tuples

face_boundary(face)

Returns a set of edges bounding the face.

The edges are tuples orded by the orientation of the face.

Parameters:

facetuple: The face to be investigated.

Returns:

tuple: tuple with ordered edge tuples

Examples

>>> from ddg.indexedfaceset import GeneralizedIndexedFaceSet
>>> faceSet = GeneralizedIndexedFaceSet([(1, 2, 4), (2, 3, 4)])
>>> faceSet.face_boundary((1, 2, 4))
((1, 2), (2, 4), (4, 1))

face_edge_list(edge_index)

Method to find the faces which share a specific edge

Parameters:

edge_indexint: The index of the edge

Returns:

numpy.ndarray: For non-uniform meshes the return value is a 1D array of faces as tuples For uniform meshes the return value is a 2D array

face_list()

Get all faces of the indexed face set.

Returns:

list: List of tuples representing the faces of the indexed face set.

face_vertex_dict(vertex_index)

Method to create a dictionary which has as values the arrays of faces with which they share a specific vertex and as keys the number of edges of the faces

Parameters:

vertex_indexint: The index of the vertex to be found (0,…, n-1)

Returns:

dict: Keys : the number of edges of faces Values : thoses faces with the key number of edges which share the input vertex

face_vertex_list(vertex_index)

Method to find the faces which share a specific vertex

Parameters:

vertex_indexint: The index of the vertex to be found (0,…, n-1)

Returns:

numpy.ndarray: returns indices of faces

get_attribute(attr_name, cell_type, cell)

‘Get’ method corresponding the attribute structure of the subclass to override the same method in the parent class

Parameters:

cell_typestr: Type of cell from which the attribute are to be recalled
cell_typestr: Type of cell from which the attribute is to be retrieved
cellint for verts, int or tuples for edges and faces: The cell or its index. For vertices, these two are the same. For edges and faces these are different. Both form are accepted.

Returns:

numpy.ndarray: The attribute in the specified position.

get_vertex_set(): Returns the set of vertices of an indexed face set

is_boundary_vertex(vertex_index)

checks if a vertex is a boundary vertex or not

Parameters:

vertex_index1D list or array: the index of the vertex in question

Returns:

True if the the vertex is a boundary vertex, otherwise False

neighboring_faces(face)

Get all faces that are adjacent to a given a face.

If an edge has none or more than one other neighbouring faces, None will be returned.

Parameters:

facetuple: The input face whose neighbouring faces will be determined.

Returns:

list

List of neighbouring faces in cyclic order. ..

Includes ..

tuple ..

If there exist exactly one neighbouring face to an edge. ..

None ..

If edge is adjacent to only one or more than two faces. ..

neighboring_faces_with_orientation(face)

Get all oriented faces that are adjacent to a given a face.

If an edge has none or more than one other neighbouring faces, None will be returned.

Parameters:

facetuple: The input face whose neighbouring faces will be determined.

Returns:

list

List of neighbouring faces in cyclic order. ..

Includes ..

OrientedFace ..

If there exist exactly one neighbouring face to an edge. ..

NoneFace ..

If edge is adjacent to only one or more than two faces. ..

number_of_faces()

Get the number of faces of the indexed face set.

Returns:

int: Number of faces of the indexed face set.

opposite_face(face, edge)

Get the other face adjacent to a given edge of a face.

If the edge is adjacent to only one or more than two faces return None.

Parameters:

edgetuple: Tuple of two integers.
facetuple: The input face incuding the edge from which the other face will be determined.

Returns:

tuple: The other face incident to the given edge.
None: If edge is adjacent to only one or more than two faces.

opposite_face_with_orientation(face, edge)

Get the other oriented face adjacent to a given edge of a face.

If the edge is adjacent to only one or more than two faces return None.

Parameters:

edgetuple: Tuple of two integers.
facetuple: The input face incuding the edge from which the other face will be determined.

Returns:

OrientedFace: The other face incident to the given edge.
NoneFace: If edge is adjacent to only one or more than two faces.

set_attribute(attr_name, cell_type, attribute, dtype=<class 'float'>)

Method to create a dictionary of attributes for a given cell type.

Parameters:

attr_namestr: Name of the attribute to get in string
attributenp.ndarray: An array of the attributes to be set

Returns:

Attribute dictionary

class ddg.indexedfaceset.NoneFace[source]

Bases: OrientedFace

get_orientation()

get_oriented_tuple()

get_tuple()

set_orientation(new_orientation)

class ddg.indexedfaceset.OrientedFace(index_tuple, orientation=1)[source]

Bases: object

get_orientation()[source]

get_oriented_tuple()[source]

get_tuple()[source]

set_orientation(new_orientation)[source]

class ddg.indexedfaceset.OrientedIndexedFaceSet(face_list=[])[source]

Bases: GeneralizedIndexedFaceSet

adjacent_faces(edge)[source]: Get a list of faces adjacent to an edge given as a tuple of integers. The faces are ordered such that they contain the given edge in the given orientation.

add_face(face)[source]

Adds face to the indexed face set.

Simply adds the face without paying attention to the maifold property.

Parameters:

facetuple: The face to be investigated.

adjacent_faces_with_orientation(edge)

Get a list of oriented faces adjacent to an given edge.

The resulting faces are of the class OrientedFace with self.orientation = 1 if they contain the edge in the given orientation or self.orientation = -1 if they contain the edge in reversed orientation.

Parameters:

edgetuple: Tuple of two integers.

Returns:

list: List of instances of the class OrientedFace that are adjacent to the input edge.

delete_attribute(attr_name, cell_type)

Deletes the attribute given by its name

Parameters:

attr_namestr: Name of the attribute
cell_type: str: Type of cell to which the attribute must be added

edge_set()

Get all edges of the indexed face set.

Returns:

set: Unordered set of tuples of two integers representing all edges.

face_boundary(face)

Returns a set of edges bounding the face.

The edges are tuples orded by the orientation of the face.

Parameters:

facetuple: The face to be investigated.

Returns:

tuple: tuple with ordered edge tuples

Examples

>>> from ddg.indexedfaceset import GeneralizedIndexedFaceSet
>>> faceSet = GeneralizedIndexedFaceSet([(1, 2, 4), (2, 3, 4)])
>>> faceSet.face_boundary((1, 2, 4))
((1, 2), (2, 4), (4, 1))

face_list()

Get all faces of the indexed face set.

Returns:

list: List of tuples representing the faces of the indexed face set.

get_attribute(attr_name, cell_type, cell)

get cell attribute

Parameters:

attr_namestr: Name of the attribute. Represents keys for the attribute dictionaries
cell_typestr: Type of cell from which the attribute is to be retrieved
cellfloat or int for verts, tuples for edges and faces: The cell to which the attribute is assigned. Type depends on the type of the inputs given to create the class.

Returns:

The attribute in the specified position. Type depends on the attribute type.

get_vertex_set(): Returns the set of vertices of an indexed face set

neighboring_faces(face)

Get all faces that are adjacent to a given a face.

If an edge has none or more than one other neighbouring faces, None will be returned.

Parameters:

facetuple: The input face whose neighbouring faces will be determined.

Returns:

list

List of neighbouring faces in cyclic order. ..

Includes ..

tuple ..

If there exist exactly one neighbouring face to an edge. ..

None ..

If edge is adjacent to only one or more than two faces. ..

neighboring_faces_with_orientation(face)

Get all oriented faces that are adjacent to a given a face.

If an edge has none or more than one other neighbouring faces, None will be returned.

Parameters:

facetuple: The input face whose neighbouring faces will be determined.

Returns:

list

List of neighbouring faces in cyclic order. ..

Includes ..

OrientedFace ..

If there exist exactly one neighbouring face to an edge. ..

NoneFace ..

If edge is adjacent to only one or more than two faces. ..

number_of_faces()

Get the number of faces of the indexed face set.

Returns:

int: Number of faces of the indexed face set.

opposite_face(face, edge)

Get the other face adjacent to a given edge of a face.

If the edge is adjacent to only one or more than two faces return None.

Parameters:

edgetuple: Tuple of two integers.
facetuple: The input face incuding the edge from which the other face will be determined.

Returns:

tuple: The other face incident to the given edge.
None: If edge is adjacent to only one or more than two faces.

opposite_face_with_orientation(face, edge)

Get the other oriented face adjacent to a given edge of a face.

If the edge is adjacent to only one or more than two faces return None.

Parameters:

edgetuple: Tuple of two integers.
facetuple: The input face incuding the edge from which the other face will be determined.

Returns:

OrientedFace: The other face incident to the given edge.
NoneFace: If edge is adjacent to only one or more than two faces.

set_attribute(attr_name, cell_type, attribute, cell_subset=None)

Method to add attributes to cells of an ifs. If the attribute already exists, it changes it. If only a subset is specified, it only updates the subset values.

Parameters:

cell_type: str: Type of cell to which the attribute must be added
attr_namestr: Name of the attribute
attributeSubscriptable object: A subscriptable object of the attributes to be assigned to each vertex
cell_subset: set or list depending on the cell type: if the cells in question are not the whole cells of the ifs but a subset of it, they must be given as input in this parameter

Returns:

dict: A nested dictionary of all attributes of vertices