class DreyfusIMR:
def __init__(self,
graph,
terminals,
contract_graph=True,
contracted_graph=None,
within_convex_hull=False,
dist_paths=None,
nodes=None):
# Check whether graph is node-weighted.
if not graph.is_node_weighted():
raise (
ValueError,
"Dreyfus with IMRs algorithm only works with node-weighted graphs."
)
# Extract POI from the terminals list.
if len(terminals) > 0:
self.__poi = terminals[0]
else:
return
# Set object variables.
generator = SuitableNodeWeightGenerator()
self.__original_graph = graph
self.__terminals = terminals
self.__contract_graph = contract_graph
# Contracted graph...
if contract_graph:
if contracted_graph is not None:
self.__graph = contracted_graph.copy()
else:
self.__graph = SuitabilityGraph()
self.__graph.append_graph(graph)
self.__graph.contract_suitable_regions(
generator, excluded_nodes=terminals)
else:
self.__graph = SuitabilityGraph()
self.__graph.append_graph(graph)
#
if nodes is not None:
self.__nodes = list(nodes)
else:
if within_convex_hull:
pass
# self.__nodes = self.__graph.get_suitable_nodes_within_convex_set(terminals, generator, dist_paths)
else:
self.__nodes = self.__graph.get_suitable_nodes(
generator, excluded_nodes=terminals)
#
for t in terminals:
self.__nodes.append(t)
# print(self.__nodes)
#
self.__dist = {}
self.__paths = {}
if dist_paths is not None:
self.__dist = dict(dist_paths[0])
self.__paths = dict(dist_paths[1])
else:
self.__dist, self.__paths = self.__graph.get_dist_paths(
origins=self.__nodes, destinations=self.__nodes)
#
self.__s_d = {}
'''
'''
def steiner_tree(self, consider_terminals=False):
#
set_c = tuple(sorted(self.__terminals[1:]))
t_tuples = [tuple([t]) for t in set_c]
#
for j in self.__nodes:
self.__s_d[j] = {}
for t in t_tuples:
try:
self.__s_d[j][t] = [
self.__dist[tuple(sorted([j, t[0]]))], t[0],
(None, None)
]
except KeyError:
self.__s_d[j][t] = [sys.maxint, t[0], (None, None)]
#
for m in range(2, len(set_c)):
#
sets_d = [tuple(set_d) for set_d in comb(set_c, m)]
for set_d in sets_d:
#
for i in self.__nodes:
self.__s_d[i][set_d] = [sys.maxint, None, (None, None)]
#
sets_e = self.__create_subsets_e(set_d)
#
for j in self.__nodes:
u = sys.maxint
best_subsets = None
for set_e in sets_e:
set_f = tuple(sorted(list(set(set_d) - set(set_e))))
if len(set_f) > 0:
s = self.__s_d[j][set_e][0] + self.__s_d[j][set_f][
0]
else:
s = self.__s_d[j][set_e][0]
if s < u:
u = s
best_subsets = (set_e, set_f)
for i in self.__nodes:
try:
dist = self.__dist[tuple(sorted([i, j]))]
except KeyError:
dist = sys.maxint
if consider_terminals:
if dist + u < self.__s_d[i][set_d][0]:
self.__s_d[i][set_d] = [
dist + u, j, best_subsets
]
else:
if dist + u < self.__s_d[i][set_d][
0] and j not in self.__terminals[1:]:
self.__s_d[i][set_d] = [
dist + u, j, best_subsets
]
#
sets_e = self.__create_subsets_e(set_c)
#
cost = sys.maxint
if self.__poi not in self.__s_d:
self.__s_d[self.__poi] = {set_c: [cost, None, (None, None)]}
else:
self.__s_d[self.__poi][set_c] = [cost, None, (None, None)]
#
for j in self.__nodes:
u = sys.maxint
best_subsets = None
for set_e in sets_e:
set_f = tuple(sorted(list(set(set_c) - set(set_e))))
if len(set_f) > 0:
s = self.__s_d[j][set_e][0] + self.__s_d[j][set_f][0]
else:
s = self.__s_d[j][set_e][0]
if s < u:
u = s
best_subsets = (set_e, set_f)
try:
dist = self.__dist[tuple(sorted([self.__poi, j]))]
except KeyError:
dist = sys.maxint
if consider_terminals:
if dist + u < cost:
cost = dist + u
self.__s_d[self.__poi][set_c] = [cost, j, best_subsets]
else:
if dist + u < cost and j not in self.__terminals[1:]:
cost = dist + u
self.__s_d[self.__poi][set_c] = [cost, j, best_subsets]
# Reconstruct the Steiner by backtracking
steiner_tree = self.__build_steiner_tree_bactracking(self.__poi, set_c)
if self.__contract_graph:
self.__decontract_steiner_tree(steiner_tree)
return steiner_tree
'''
'''
@staticmethod
def __create_subsets_e(set_):
sets_e = [tuple([set_[0]])]
l_set = len(set_)
for x in range(1, l_set - 1):
for y in comb(set_[1:], x):
t = [set_[0]]
t.extend(y)
sets_e.append(tuple(t))
return sets_e
'''
'''
def __build_steiner_tree_bactracking(self, node, subset):
steiner_tree = SuitabilityGraph()
next_node = self.__s_d[node][tuple(subset)][1]
print(node, self.__s_d[node][tuple(subset)])
# pdb.set_trace()
if next_node is not None:
steiner_tree.append_path(
self.__paths[tuple(sorted([node, next_node]))], self.__graph)
(best_e, best_f) = self.__s_d[node][tuple(subset)][2]
# pdb.set_trace()
steiner_branch_e = SuitabilityGraph()
if best_e is not None and best_e != [next_node]:
steiner_branch_e = self.__build_steiner_tree_bactracking(
next_node, best_e)
steiner_branch_f = SuitabilityGraph()
if best_f is not None and best_f != [next_node] and len(best_f) > 0:
steiner_branch_f = self.__build_steiner_tree_bactracking(
next_node, best_f)
steiner_tree.append_graph(steiner_branch_e)
steiner_tree.append_graph(steiner_branch_f)
return steiner_tree
'''
'''
def __find_closest_node_to_node_within_region(self, node, region_id):
region = self.__graph.contracted_regions[region_id][0]
min_dist = sys.maxint
closest_node = None
distances, paths = dijkstra(self.__original_graph, node, region.keys())
for n in region:
if distances[n] < min_dist:
closest_node = n
min_dist = distances[n]
return closest_node, paths[closest_node]
'''
'''
def __decontract_steiner_tree(self, steiner_tree):
regions = []
paths = []
trees = []
for n in steiner_tree:
try:
if n in self.__graph.contracted_regions:
dropped_edges = steiner_tree[n][2]['dropped_edges']
neighbors = steiner_tree[n][1].keys()
new_terminals = set()
for b in neighbors:
t = dropped_edges[b]
new_terminals.add(t)
if b in self.__graph.auxiliary_nodes:
bb = [cc for cc in steiner_tree[b][1]
if cc != n][0]
paths.append([t, bb])
else:
paths.append([t, b])
if len(new_terminals) > 1:
region = self.__graph.contracted_regions[n][0]
d = DreyfusIMR(region,
list(new_terminals),
contract_graph=False)
st = d.steiner_tree()
trees.append(st)
regions.append(n)
except KeyError:
pass
for r in regions:
del steiner_tree[r]
for p in paths:
steiner_tree.append_path(p, self.__original_graph)
for st in trees:
steiner_tree.append_graph(st)
class ClusterBased:
def __init__(self, graph, terminals):
# Check whether graph is node-weighted.
if not graph.is_node_weighted():
raise (
ValueError,
"Cluster-based algorithm only works with node-weighted graphs."
)
# Extract POI from the terminals list.
if len(terminals) > 0:
self.__poi = terminals[0]
else:
return
#
generator = SuitableNodeWeightGenerator()
# Set object variables.
self.__graph = SuitabilityGraph()
self.__graph.append_graph(graph)
self.__terminals = terminals
#
# self.__regions = self.__graph.get_suitable_regions(generator, excluded_nodes=terminals,
# get_border_internal_nodes=True, get_centroid_medoid=True,
# get_characteristic_nodes=True)
self.__regions = self.__graph.get_suitable_regions(
generator,
excluded_nodes=terminals,
get_border_internal_nodes=True,
get_centroid_medoid=True)
#
self.__nodes = []
for id_r in self.__regions:
#
# characteristic_nodes = self.__regions[id_r][6]
# self.__nodes.extend(characteristic_nodes)
border_nodes = self.__regions[id_r][1]
self.__nodes.extend(border_nodes)
#
# if len(characteristic_nodes) == 0:
# medoid = self.__regions[id_r][4]
# # print(medoid)
# self.__nodes.append(medoid)
for t in terminals:
self.__nodes.append(t)
#
self.__dist, self.__paths = self.__graph.get_dist_paths(
origins=self.__nodes, destinations=self.__nodes)
'''
'''
def steiner_tree(self, consider_terminals=False):
dr = DreyfusIMR(graph=self.__graph,
terminals=self.__terminals,
contract_graph=False,
nodes=self.__nodes,
dist_paths=(self.__dist, self.__paths))
if consider_terminals:
steiner_tree = dr.steiner_tree(consider_terminals=True)
else:
steiner_tree = dr.steiner_tree(consider_terminals=False)
# self.__refine_steiner_tree(steiner_tree)
return steiner_tree
'''
'''
def __refine_steiner_tree(self, steiner_tree):
clusters = []
for id_r in self.__regions:
region = self.__regions[id_r][0]
for n in steiner_tree:
if n in region:
clusters.append(id_r)
break
print clusters
class DreyfusIMRV2:
def __init__(self, graph, terminals, contract_graph=True, contracted_graph=None, within_convex_hull=False,
dist_paths=None, nodes=None, use_medoid=False):
# Check whether graph is node-weighted.
if not graph.is_node_weighted():
raise (ValueError, "Dreyfus with IMRs algorithm only works with node-weighted graphs.")
# Extract POI from the terminals list.
if len(terminals) > 0:
self.__poi = terminals[0]
else:
return
# Set object variables.
generator = SuitableNodeWeightGenerator()
self.__original_graph = graph
self.__terminals = terminals
self.__contract_graph = contract_graph
self.__use_medoid = use_medoid
# Contracted graph...
if contract_graph:
if contracted_graph is not None:
self.__graph = contracted_graph.copy()
else:
self.__graph = SuitabilityGraph()
self.__graph.append_graph(graph)
self.__graph.contract_suitable_regions(generator, excluded_nodes=terminals,
get_centroid_medoid=use_medoid)
else:
self.__graph = SuitabilityGraph()
self.__graph.append_graph(graph)
#
if nodes is not None:
self.__nodes = list(nodes)
else:
if within_convex_hull:
pass
# self.__nodes = self.__graph.get_suitable_nodes_within_convex_set(terminals, generator, dist_paths)
else:
self.__nodes = self.__graph.get_suitable_nodes(generator, excluded_nodes=terminals)
#
for t in terminals:
self.__nodes.append(t)
# print(self.__nodes)
#
self.__dist = {}
self.__paths = {}
if dist_paths is not None:
self.__dist = dict(dist_paths[0])
self.__paths = dict(dist_paths[1])
else:
self.__dist, self.__paths = self.__graph.get_dist_paths(origins=self.__nodes, destinations=self.__nodes)
#
self.__s_d = {}
'''
'''
def steiner_tree(self, consider_terminals=False):
#
set_c = tuple(sorted(self.__terminals[1:]))
t_tuples = [tuple([t]) for t in set_c]
#
for j in self.__nodes:
self.__s_d[j] = {}
for t in t_tuples:
pair_nodes = tuple(sorted([j, t[0]]))
try:
entry_node = None
if j in self.__graph.contracted_regions:
path = self.__paths[pair_nodes]
if len(path) > 1:
if path.index(j) == len(path) - 1:
entry_node = path[len(path) - 2]
else:
entry_node = path[1]
else:
# pdb.set_trace()
pass
self.__s_d[j][t] = [self.__dist[pair_nodes], t[0], (None, None), entry_node]
except KeyError:
self.__s_d[j][t] = [sys.maxint, t[0], (None, None), None]
#
for m in range(2, len(set_c)):
#
sets_d = [tuple(set_d) for set_d in comb(set_c, m)]
for set_d in sets_d:
#
for i in self.__nodes:
self.__s_d[i][set_d] = [sys.maxint, None, (None, None)]
#
sets_e = self.__create_subsets_e(set_d)
#
for j in self.__nodes:
u = sys.maxint
best_subsets = None
for set_e in sets_e:
set_f = tuple(sorted(list(set(set_d) - set(set_e))))
if len(set_f) > 0:
s = self.__s_d[j][set_e][0] + self.__s_d[j][set_f][0]
else:
s = self.__s_d[j][set_e][0]
#
if s < u:
u = s
best_subsets = (set_e, set_f)
for i in self.__nodes:
pair_nodes = tuple(sorted([i, j]))
# d_n1_n3 = d_n2_n3 = 0
d1 = d2 = d3 = 0
try:
dist = self.__dist[pair_nodes]
if j in self.__graph.contracted_regions and best_subsets is not None:
e_n_1 = self.__s_d[j][best_subsets[0]][3]
e_n_2 = self.__s_d[j][best_subsets[1]][3]
path = self.__paths[pair_nodes]
dropped_edges = self.__graph[j][2]['dropped_edges']
dist_paths = self.__graph[j][2]['dist_paths']
n1 = dropped_edges[e_n_1]
n2 = dropped_edges[e_n_2]
if len(path) > 1:
if path.index(j) == len(path) - 1:
e_n_3 = path[len(path) - 2]
else:
e_n_3 = path[1]
n3 = dropped_edges[e_n_3]
dr = DreyfusIMR(self.__graph.contracted_regions[j][0], terminals=[n1, n2, n3],
contract_graph=False)
st = dr.steiner_tree()
d1, _ = st.compute_total_weights()
# # Use the medoid to compute the internal distance.
# if self.__use_medoid:
# medoid = self.__graph.contracted_regions[j][4]
# d1 = dist_paths[0][tuple(sorted([n1, medoid]))]
# d2 = dist_paths[0][tuple(sorted([n2, medoid]))]
# d3 = dist_paths[0][tuple(sorted([n3, medoid]))]
# else:
# d1 = dist_paths[0][tuple(sorted([n1, n3]))]
# d2 = dist_paths[0][tuple(sorted([n2, n3]))]
# elif j == i:
# d1 = dist_paths[0][tuple(sorted([n1, n2]))]
except KeyError:
dist = sys.maxint
cost = dist + u + d1 + d2 + d3
if consider_terminals:
if cost < self.__s_d[i][set_d][0]:
self.__s_d[i][set_d] = [cost, j, best_subsets]
#####################IMPORTANT: NOT COMPLETELY IMPLEMENTED!!!#####################
else:
if cost < self.__s_d[i][set_d][0] and j not in self.__terminals:
entry_node = None
if i in self.__graph.contracted_regions:
try:
path = self.__paths[pair_nodes]
if path.index(i) == len(path) - 1:
entry_node = path[len(path) - 2]
else:
entry_node = path[1]
except KeyError:
pass
self.__s_d[i][set_d] = [cost, j, best_subsets, entry_node]
#
sets_e = self.__create_subsets_e(set_c)
#
if self.__poi not in self.__s_d:
self.__s_d[self.__poi] = {set_c: [sys.maxint, None, (None, None), None]}
else:
self.__s_d[self.__poi][set_c] = [sys.maxint, None, (None, None), None]
#
for j in self.__nodes:
u = sys.maxint
best_subsets = None
for set_e in sets_e:
set_f = tuple(sorted(list(set(set_c) - set(set_e))))
if len(set_f) > 0:
s = self.__s_d[j][set_e][0] + self.__s_d[j][set_f][0]
else:
s = self.__s_d[j][set_e][0]
if s < u:
u = s
best_subsets = (set_e, set_f)
pair_nodes = tuple(sorted([self.__poi, j]))
# d_n1_n3 = d_n2_n3 = 0
d1 = d2 = d3 = 0
try:
dist = self.__dist[pair_nodes]
if j in self.__graph.contracted_regions and best_subsets is not None:
e_n_1 = self.__s_d[j][best_subsets[0]][3]
e_n_2 = self.__s_d[j][best_subsets[1]][3]
path = self.__paths[pair_nodes]
if len(path) > 1:
if path.index(j) == len(path) - 1:
e_n_3 = path[len(path) - 2]
else:
e_n_3 = path[1]
dropped_edges = self.__graph[j][2]['dropped_edges']
dist_paths = self.__graph[j][2]['dist_paths']
n1 = dropped_edges[e_n_1]
n2 = dropped_edges[e_n_2]
n3 = dropped_edges[e_n_3]
dr = DreyfusIMR(self.__graph.contracted_regions[j][0], terminals=[n1, n2, n3], contract_graph=False)
st = dr.steiner_tree()
d1, _ = st.compute_total_weights()
# Use the medoid to compute the internal distance.
# if self.__use_medoid:
# medoid = self.__graph.contracted_regions[j][4]
# d1 = dist_paths[0][tuple(sorted([n1, medoid]))]
# d2 = dist_paths[0][tuple(sorted([n2, medoid]))]
# d3 = dist_paths[0][tuple(sorted([n3, medoid]))]
# else:
# d1 = dist_paths[0][tuple(sorted([n1, n3]))]
# d2 = dist_paths[0][tuple(sorted([n2, n3]))]
except KeyError:
dist = sys.maxint
cost = dist + u + d1 + d2 + d3
if consider_terminals:
if cost < self.__s_d[self.__poi][set_c][0]:
self.__s_d[self.__poi][set_c] = [cost, j, best_subsets]
#####################IMPORTANT: NOT COMPLETELY IMPLEMENTED!!!#####################
else:
if cost < self.__s_d[self.__poi][set_c][0] and j not in self.__terminals:
self.__s_d[self.__poi][set_c] = [cost, j, best_subsets, None]
# Reconstruct the Steiner by backtracking
steiner_tree = self.__build_steiner_tree_bactracking(self.__poi, set_c)
if self.__contract_graph:
self.__decontract_steiner_tree(steiner_tree)
return steiner_tree
'''
'''
@staticmethod
def __create_subsets_e(set_):
sets_e = [tuple([set_[0]])]
l_set = len(set_)
for x in range(1, l_set - 1):
for y in comb(set_[1:], x):
t = [set_[0]]
t.extend(y)
sets_e.append(tuple(t))
return sets_e
'''
'''
def __build_steiner_tree_bactracking(self, node, subset):
steiner_tree = SuitabilityGraph()
next_node = self.__s_d[node][tuple(subset)][1]
if self.__contract_graph:
print(node, self.__s_d[node][tuple(subset)])
# pdb.set_trace()
if next_node is not None:
steiner_tree.append_path(self.__paths[tuple(sorted([node, next_node]))], self.__graph)
(best_e, best_f) = self.__s_d[node][tuple(subset)][2]
# pdb.set_trace()
steiner_branch_e = SuitabilityGraph()
if best_e is not None and best_e != [next_node]:
steiner_branch_e = self.__build_steiner_tree_bactracking(next_node, best_e)
steiner_branch_f = SuitabilityGraph()
if best_f is not None and best_f != [next_node] and len(best_f) > 0:
steiner_branch_f = self.__build_steiner_tree_bactracking(next_node, best_f)
steiner_tree.append_graph(steiner_branch_e)
steiner_tree.append_graph(steiner_branch_f)
return steiner_tree
'''
'''
def __find_closest_node_to_node_within_region(self, node, region_id):
region = self.__graph.contracted_regions[region_id][0]
min_dist = sys.maxint
closest_node = None
distances, paths = dijkstra(self.__original_graph, node, region.keys())
for n in region:
if distances[n] < min_dist:
closest_node = n
min_dist = distances[n]
return closest_node, paths[closest_node]
'''
'''
def __decontract_steiner_tree(self, steiner_tree):
to_drop = []
paths = []
trees = []
# pdb.set_trace()
for n in steiner_tree:
try:
if n in self.__graph.contracted_regions:
dropped_edges = steiner_tree[n][2]['dropped_edges']
neighbors = steiner_tree[n][1].keys()
new_terminals = set()
for b in neighbors:
t = dropped_edges[b]
new_terminals.add(t)
if b in self.__graph.auxiliary_nodes:
bb = [cc for cc in steiner_tree[b][1] if cc != n][0]
paths.append([t, bb])
del steiner_tree[bb][1][b]
to_drop.append(b)
else:
paths.append([t, b])
del steiner_tree[b][1][n]
if len(new_terminals) > 1:
region = self.__graph.contracted_regions[n][0]
d = DreyfusIMRV2(region, list(new_terminals), contract_graph=False)
st = d.steiner_tree()
trees.append(st)
to_drop.append(n)
except KeyError:
pass
# pdb.set_trace()
for r in to_drop:
del steiner_tree[r]
for p in paths:
steiner_tree.append_path(p, self.__original_graph)
for st in trees:
steiner_tree.append_graph(st)
# pdb.set_trace()
# for r in steiner_tree:
# if r in self.__graph.contracted_regions:
# regions.append(r)
# neighbors = steiner_tree[r][1].keys()
# new_terminals = set()
# for n in neighbors:
# closest_node_to_n, path = self.__find_closest_node_to_node_within_region(n, r)
# paths.append(path)
# new_terminals.add(closest_node_to_n)
# del steiner_tree[n][1][r]
# if len(new_terminals) > 1:
# region = self.__graph.contracted_regions[r][0]
# d = DreyfusIMR(region, list(new_terminals), contract_graph=False)
# st = d.steiner_tree()
# trees.append(st)
# for r in regions:
# del steiner_tree[r]
# for p in paths:
# steiner_tree.append_from_path(p, self.__original_graph)
# for st in trees:
# steiner_tree.append_from_graph(st)
def enclosing_region(self):
enclosing = SuitabilityGraph()
paths = []
paths.append(self.__paths[tuple(sorted([323287670, 2392803740]))])
paths.append(self.__paths[tuple(sorted([2392803740, 127578100]))])
paths.append(self.__paths[tuple(sorted([127578100, 3109398450]))])
paths.append(self.__paths[tuple(sorted([3109398450, 342909685]))])
paths.append(self.__paths[tuple(sorted([342909685, 323287670]))])
for path in paths:
enclosing.append_path(path, self.__original_graph)
return enclosing