def _sort_vertex_neighbors(key, nbrs, xyz, ccw=True):
if len(nbrs) == 1:
return nbrs
ordered = nbrs[0:1]
a = xyz[key]
for i, nbr in enumerate(nbrs[1:]):
c = xyz[nbr]
pos = 0
b = xyz[ordered[pos]]
while not is_ccw_xy(a, b, c):
pos += 1
if pos > i:
break
b = xyz[ordered[pos]]
if pos == 0:
pos = -1
b = xyz[ordered[pos]]
while is_ccw_xy(a, b, c):
pos -= 1
if pos < -len(ordered):
break
b = xyz[ordered[pos]]
pos += 1
ordered.insert(pos, nbr)
if not ccw:
return ordered[::-1]
return ordered
def _sort_neighbours(network, ccw=True):
sorted_neighbours = {}
xyz = {key: network.vertex_coordinates(key) for key in network.vertices()}
for key in network.vertices():
nbrs = network.vertex_neighbours(key)
if len(nbrs) == 1:
sorted_neighbours[key] = nbrs
continue
ordered = [nbrs[0]]
a = xyz[key]
for i, nbr in enumerate(nbrs[1:]):
c = xyz[nbr]
pos = 0
b = xyz[ordered[pos]]
while not is_ccw_xy(a, b, c):
pos += 1
if pos > i:
break
b = xyz[ordered[pos]]
if pos == 0:
pos = -1
b = xyz[ordered[pos]]
while is_ccw_xy(a, b, c):
pos -= 1
if pos < -len(ordered):
break
b = xyz[ordered[pos]]
pos += 1
ordered.insert(pos, nbr)
if not ccw:
sorted_neighbours[key] = ordered[::-1]
sorted_neighbours[key] = ordered
for key, nbrs in sorted_neighbours.items():
network.vertex[key]['sorted_neighbours'] = nbrs[::-1]
return sorted_neighbours
def _find_first_neighbor(key, network):
nbrs = list(network.halfedge[key].keys())
if len(nbrs) == 1:
return nbrs[0]
ab = [-1.0, -1.0, 0.0]
a = network.vertex_coordinates(key, 'xyz')
b = [a[0] + ab[0], a[1] + ab[1], 0]
angles = []
for nbr in nbrs:
c = network.vertex_coordinates(nbr, 'xyz')
ac = [c[0] - a[0], c[1] - a[1], 0]
alpha = angle_vectors(ab, ac)
if is_ccw_xy(a, b, c, True):
alpha = PI2 - alpha
angles.append(alpha)
return nbrs[angles.index(min(angles))]
def network_node_find_first_neighbor(network, key):
nbrs = network.neighbors(key)
if len(nbrs) == 1:
return nbrs[0]
ab = [-1.0, -1.0, 0.0]
a = network.node_coordinates(key, 'xyz')
b = [a[0] + ab[0], a[1] + ab[1], 0]
angles = []
for nbr in nbrs:
c = network.node_coordinates(nbr, 'xyz')
ac = [c[0] - a[0], c[1] - a[1], 0]
alpha = angle_vectors(ab, ac)
if is_ccw_xy(a, b, c, True):
alpha = PI2 - alpha
angles.append(alpha)
return nbrs[angles.index(min(angles))]
def _find_first_neighbour(key, network):
nbrs = list(network.halfedge[key].keys())
if len(nbrs) == 1:
return nbrs[0]
vu = [-1.0, -1.0, 0.0]
a = network.vertex_coordinates(key, 'xyz')
b = [a[0] + vu[0], a[1] + vu[1], 0]
cw = []
for nbr in nbrs:
c = network.vertex_coordinates(nbr, 'xyz')
if not is_ccw_xy(a, b, c, True):
cw.append(nbr)
if cw:
nbrs = cw
angles = []
v = [network.vertex[key][_] for _ in 'xyz']
for nbr in nbrs:
w = [network.vertex[nbr][_] for _ in 'xyz']
vw = [w[0] - v[0], w[1] - v[1], 0]
angles.append(angle_vectors(vu, vw))
if cw:
return nbrs[angles.index(min(angles))]
return nbrs[angles.index(max(angles))]
def _is_point_in_edgezone(p, p0, p1):
n = cross_vectors(p1 - p0, [0, 0, 1.])
return (is_ccw_xy(p0 - p0, n, p - p0)
and not is_ccw_xy(p0 - p0, p1 - p0, p - p0)
and not is_ccw_xy(p1 - p1, n, p - p1))
def network_embed_in_plane(network, fix=None, straightline=True):
"""Embed the network in the plane.
Parameters
----------
network : Network
A network object.
fix : list (None)
Two fixed points.
straightline : bool (True)
Embed using straight lines.
Returns
-------
bool
True if the embedding was successful.
False otherwise.
Raises
------
ImportError
If NetworkX is not installed.
Warning
-------
This function uses the Python package NetworkX. NetworkX can be *pip installed*.
Examples
--------
.. plot::
:include-source:
import compas
from compas.datastructures import Network
from compas.topology import network_embed_in_plane
from compas.plotters import NetworkPlotter
network = Network.from_obj(compas.get('fink.obj'))
embedding = network.copy()
fix = (1, 12)
if network_embed_in_plane(embedding, fix=fix):
plotter = NetworkPlotter(embedding)
plotter.draw_lines([{'start': network.vertex_coordinates(u, 'xy'),
'end': network.vertex_coordinates(v, 'xy'),
'color': '#cccccc'} for u, v in network.edges()])
plotter.draw_vertices(radius=0.3,
text={key: key for key in embedding.vertices()},
facecolor={key: '#ff0000' for key in fix})
plotter.draw_edges()
plotter.show()
"""
try:
import networkx as nx
except ImportError:
print(
"NetworkX is not installed. Get NetworkX at https://networkx.github.io/."
)
raise
x = network.get_vertices_attribute('x')
y = network.get_vertices_attribute('y')
xmin, xmax = min(x), max(x)
ymin, ymax = min(y), max(y)
xspan = xmax - xmin
yspan = ymax - ymin
edges = [(u, v) for u, v in network.edges()
if not network.is_vertex_leaf(u) and not network.is_vertex_leaf(v)
]
is_embedded = False
count = 100
while count:
graph = nx.Graph(edges)
pos = nx.spring_layout(graph,
2,
iterations=100,
scale=max(xspan, yspan))
if not _network_are_edges_crossed(edges, pos):
is_embedded = True
break
count -= 1
if not is_embedded:
return False
if fix:
a, b = fix
p0 = network.vertex_coordinates(a, 'xy')
p1 = network.vertex_coordinates(b, 'xy')
p2 = pos[b]
vec0 = [
network.vertex[b][axis] - network.vertex[a][axis] for axis in 'xy'
]
vec1 = [pos[b][axis] - pos[a][axis] for axis in (0, 1)]
# rotate
a = angle_vectors_xy(vec0, vec1)
if is_ccw_xy(p0, p1, p2):
a = 2 * pi - a
cosa = cos(a)
sina = sin(a)
for key in pos:
x, y = pos[key]
pos[key][0] = cosa * x - sina * y
pos[key][1] = sina * x + cosa * y
# scale
l0 = (vec0[0]**2 + vec0[1]**2)**0.5
l1 = (vec1[0]**2 + vec1[1]**2)**0.5
scale = l0 / l1
for key in pos:
pos[key][0] *= scale
pos[key][1] *= scale
# translate
t = network.vertex[fix[0]]['x'] - pos[fix[0]][0], network.vertex[
fix[0]]['y'] - pos[fix[0]][1]
for key in pos:
pos[key][0] += t[0]
pos[key][1] += t[1]
# update network vertex coordinates
for key in network.vertices():
if key in pos:
network.vertex[key]['x'] = pos[key][0]
network.vertex[key]['y'] = pos[key][1]
return True
def network_embed_in_plane(network, fixed=None, straightline=True):
"""Embed the network in the plane.
Parameters
----------
network : Network
A network object.
fixed : list (None)
Two fixed points.
straightline : bool (True)
Embed using straight lines.
Returns
-------
bool
True if the embedding was successful.
False otherwise.
Raises
------
ImportError
If NetworkX is not installed.
Examples
--------
>>>
"""
try:
import networkx as nx
except ImportError:
print(
"NetworkX is not installed. Get NetworkX at https://networkx.github.io/."
)
raise
x = network.nodes_attribute('x')
y = network.nodes_attribute('y')
xmin, xmax = min(x), max(x)
ymin, ymax = min(y), max(y)
xspan = xmax - xmin
yspan = ymax - ymin
edges = [(u, v) for u, v in network.edges()
if not network.is_leaf(u) and not network.is_leaf(v)]
is_embedded = False
count = 100
while count:
graph = nx.Graph(edges)
pos = nx.spring_layout(graph, iterations=100, scale=max(xspan, yspan))
if not _are_edges_crossed(edges, pos):
is_embedded = True
break
count -= 1
if not is_embedded:
return False
if fixed:
a, b = fixed
p0 = network.node_attributes(a, 'xy')
p1 = network.node_attributes(b, 'xy')
p2 = pos[b]
vec0 = subtract_vectors_xy(p1, p0)
vec1 = subtract_vectors_xy(pos[b], pos[a])
# rotate
angle = angle_vectors_xy(vec0, vec1)
if is_ccw_xy(p0, p1, p2):
angle = 2 * pi - angle
cosa = cos(angle)
sina = sin(angle)
for key in pos:
x, y = pos[key]
pos[key][0] = cosa * x - sina * y
pos[key][1] = sina * x + cosa * y
# scale
l0 = (vec0[0]**2 + vec0[1]**2)**0.5
l1 = (vec1[0]**2 + vec1[1]**2)**0.5
scale = l0 / l1
for key in pos:
pos[key][0] *= scale
pos[key][1] *= scale
# translate
t = subtract_vectors_xy(p0, pos[a])
for key in pos:
pos[key][0] += t[0]
pos[key][1] += t[1]
# update network node coordinates
for key in network.nodes():
if key in pos:
network.node_attributes(key, 'xy', pos[key])
return True
def network_embed_in_plane(network, fix=None, straightline=True):
"""Embed the network in the plane.
Parameters:
network (compas.datastructures.network.Network): The network object.
fix (list): Optional.
Two fixed points.
Default is ``None``.
straightline (bool): Optional.
Embed using straight lines.
Default is ``True``.
Returns:
bool:
``True`` if the embedding was successful.
``False`` otherwise.
Raises:
ImportError: If NetworkX is not installed.
Example:
.. plot::
:include-source:
import compas
from compas.datastructures.network import Network
from compas.visualization.plotters import NetworkPlotter
from compas.datastructures.network.algorithms import network_embed_in_plane
network = Network.from_obj(compas.get_data('fink.obj'))
embedding = network.copy()
fix = (1, 12)
if network_embed_in_plane(embedding, fix=fix):
plotter = NetworkPlotter(embedding)
points = []
for key in network:
points.append({
'pos': network.vertex_coordinates(key, 'xy'),
'radius': 0.1
})
lines = []
for u, v in network.edges():
lines.append({
'start': network.vertex_coordinates(u, 'xy'),
'end' : network.vertex_coordinates(v, 'xy'),
'color': '#cccccc',
})
plotter.draw_xlines(lines)
plotter.draw_xpoints(points)
plotter.draw_edges()
plotter.draw_vertices(facecolor={key: ('#ff0000' if key in fix else '#ffffff') for key in embedding.vertices()}, text={key: key for key in fix})
plotter.show()
"""
try:
import networkx as nx
except ImportError:
print(
"NetworkX is not installed. Get NetworkX at https://networkx.github.io/."
)
raise
x = network.get_vertices_attribute('x')
y = network.get_vertices_attribute('y')
xmin, xmax = min(x), max(x)
ymin, ymax = min(y), max(y)
xspan = xmax - xmin
yspan = ymax - ymin
edges = [(u, v) for u, v in network.edges()
if not network.is_vertex_leaf(u) and not network.is_vertex_leaf(v)
]
is_embedded = False
count = 100
while count:
graph = nx.Graph(edges)
pos = nx.spring_layout(graph,
2,
iterations=100,
scale=max(xspan, yspan))
if not _network_are_edges_crossed(edges, pos):
is_embedded = True
break
count -= 1
if not is_embedded:
return False
if fix:
a, b = fix
p0 = network.vertex_coordinates(a, 'xy')
p1 = network.vertex_coordinates(b, 'xy')
p2 = pos[b]
vec0 = [network[b][axis] - network[a][axis] for axis in 'xy']
vec1 = [pos[b][axis] - pos[a][axis] for axis in (0, 1)]
# rotate
a = angle_smallest_vectors_xy(vec0, vec1)
if is_ccw_xy(p0, p1, p2):
a = 2 * pi - a
cosa = cos(a)
sina = sin(a)
for key in pos:
x, y = pos[key]
pos[key][0] = cosa * x - sina * y
pos[key][1] = sina * x + cosa * y
# scale
l0 = (vec0[0]**2 + vec0[1]**2)**0.5
l1 = (vec1[0]**2 + vec1[1]**2)**0.5
scale = l0 / l1
for key in pos:
pos[key][0] *= scale
pos[key][1] *= scale
# translate
t = network[fix[0]]['x'] - pos[fix[0]][0], network[fix[0]]['y'] - pos[
fix[0]][1]
for key in pos:
pos[key][0] += t[0]
pos[key][1] += t[1]
# update network vertex coordinates
for key in network:
if key in pos:
network[key]['x'] = pos[key][0]
network[key]['y'] = pos[key][1]
return True
