def get_nd_regular_implicit_graph(shape, neighbour_list):
"""
Creates an implicit regular graph of the given :attr:`shape` with the adjacency given as a
:attr:`neighbour_list`.
See the helper function :func:`~higra.mask_2_neighbours` to create a suitable :attr:`neighbour_list`.
:Example:
Create a 2d 4-adjacency implicit graph of size ``(13, 24)``:
>>> graph = get_nd_regular_implicit_graph((13, 24), ((-1, 0), (0, -1), (0, 1), (1, 0)))
Create a 3d 6-adjacency implicit graph of size ``(10, 13, 24)``:
>>> mask = [[[0, 0, 0], [0, 1, 0], [0, 0, 0]],
>>> [[0, 1, 0], [1, 0, 1], [0, 1, 0]],
>>> [[0, 0, 0], [0, 1, 0], [0, 0, 0]]]
>>> neighbours = mask_2_neighbours(mask)
>>> graph = get_nd_regular_implicit_graph((10, 13, 24), neighbours)
:param shape: a tuple of :math:`n` elements representing the dimension of the graph vertices.
:param neighbour_list: a 2d array of :math:`k` :math:`n`-d integer vectors
:return: an implicit regular graph
"""
neighbour_list = np.asarray(neighbour_list)
if not np.issubdtype(neighbour_list.dtype, np.integer):
raise ValueError("'neighbour_list' must be of integral type.")
if neighbour_list.ndim != 2:
raise ValueError("'neighbour_list' must be a 2d array.")
shape = hg.normalize_shape(shape)
if len(shape) != neighbour_list.shape[1]:
raise ValueError(
"Shape size does not match provided adjacency dimension.")
if len(shape) > 5 or len(shape) == 0:
raise ValueError("Shape size must between 1 and 5 (included).")
if len(shape) == 1:
graph = hg.RegularGraph1d(shape, neighbour_list)
elif len(shape) == 2:
graph = hg.RegularGraph2d(shape, neighbour_list)
elif len(shape) == 3:
graph = hg.RegularGraph3d(shape, neighbour_list)
elif len(shape) == 4:
graph = hg.RegularGraph4d(shape, neighbour_list)
elif len(shape) == 5:
graph = hg.RegularGraph5d(shape, neighbour_list)
hg.CptGridGraph.link(graph, shape)
hg.set_attribute(graph, "no_border_vertex_out_degree",
neighbour_list.shape[0])
return graph
def test_create_graph(self):
shape = (2, 3)
nl = ((-1, 0), (0, -1), (0, 1), (1, 0))
g1 = hg.RegularGraph2d(hg.EmbeddingGrid2d(shape), nl)
g2 = hg.get_4_adjacency_implicit_graph(shape)
g3 = hg.get_8_adjacency_implicit_graph(shape)
for g in (g1, g2, g3):
self.assertTrue(g.num_vertices() == 6)
self.assertTrue(np.all(g1.shape() == shape))
self.assertTrue(np.all(g1.neighbour_list() == nl))
g4 = hg.RegularGraph2d(g1.shape(), g1.neighbour_list())
self.assertTrue(np.all(g4.shape() == shape))
self.assertTrue(np.all(g4.neighbour_list() == nl))
def test_create_graph(self):
shape = (2, 3)
nl = ((-1, 0), (0, -1), (0, 1), (1, 0))
g1 = hg.RegularGraph2d(hg.EmbeddingGrid2d(shape), nl)
g2 = hg.get_4_adjacency_implicit_graph(shape)
g3 = hg.get_8_adjacency_implicit_graph(shape)
for g in (g1, g2, g3):
self.assertTrue(g.num_vertices() == 6)
def get_4_adjacency_implicit_graph(shape):
"""
Create an implicit undirected 4 adjacency graph of the given shape (edges are not stored).
:param shape: a pair (height, width)
:return: a graph (Concept :class:`~higra.CptGridGraph`)
"""
shape = hg.normalize_shape(shape)
if len(shape) != 2:
raise ValueError("Shape must be a 1d array of size 2.")
neighbours = np.array(((-1, 0), (0, -1), (0, 1), (1, 0)), dtype=np.int64)
graph = hg.RegularGraph2d(shape, neighbours)
hg.CptGridGraph.link(graph, shape)
hg.set_attribute(graph, "no_border_vertex_out_degree", 4)
return graph