def sort_quanta(distances):
"""
Solves the travelling salesman problem, with a magic zero-point, to
find the shortest Hamiltonian path through the points. Returns the
indices of the points in their sorted order.
Call via get_codebook.
Args:
distances (ndarray): The distance matrix from ``get_distances()``.
Returns:
ndarray. A 1D array of size (n_colours).
"""
# Set up the file describing the problem.
outf = "/tmp/route.tsp"
with open(outf, 'w') as f:
f.write(dumps_matrix(distances, name="Route"))
# Run the solver.
tour = run(outf, start=0, solver="LKH")
result = np.array(tour['tour'])
# Slice off the initial value and the last value to account for the added
# colours. Then subtract one to shift indices back to proper range.
return result[1:-1] - 1
def test_tour_LKH(matrix):
matrix_sym = atsp_tsp(matrix, strategy="avg")
outf = "/tmp/myroute_lkh.tsp"
with open(outf, 'w') as dest:
dest.write(dumps_matrix(matrix_sym, name="My Route"))
tour = run(outf, start=10, solver="lkh")
assert tour['solution'] == 102975
assert tour['tour'][0] == 10
def test_tour_LKH(matrix):
matrix_sym = atsp_tsp(matrix, strategy="avg")
outf = "/tmp/myroute_lkh.tsp"
with open(outf, 'w') as dest:
dest.write(dumps_matrix(matrix_sym, name="My Route"))
tour = run(outf, start=10, solver="lkh")
assert tour['solution'] == 102975
assert tour['tour'][0] == 10
matrix = [[0, 2910, 4693], [2903, 0, 5839], [4695, 5745, 0]]
from pytsp import atsp_tsp, run, dumps_matrix
matrix_sym = atsp_tsp(matrix, strategy="avg")
outf = "./tsp_dist.tsp"
with open(outf, 'w') as dest:
dest.write(dumps_matrix(matrix_sym, name="My Route"))
tour = run(outf, start=None, solver="lkh")
print("tour", tour)
def lkh_TSP(list_of_kingdom_names, starting_kingdom, adjacency_matrix,
conquered_kingdoms_indices, N, dict_kingdom_index_to_name,
dict_kingdom_name_to_index, tuples_kingdom_name_to_cost,
starting_kingdom_index, dict_kingdom_index_to_cost,
adjacency_lists):
# Build TSP Distance matrix
special_nodes = conquered_kingdoms_indices
if starting_kingdom_index not in special_nodes:
special_nodes.append(starting_kingdom_index)
G = adjacency_matrix_to_graph(adjacency_matrix)
shortest_lengths = dict(nx.shortest_path_length(G, weight="weight"))
shortest_paths = dict(nx.shortest_path(G, weight="weight"))
# print(shortest_lengths)
N_TSP = len(special_nodes)
dict_TSP_index_to_index = {
TSP_index: index
for TSP_index, index in enumerate(special_nodes)
}
dict_index_to_TSP_index = {
index: TSP_index
for TSP_index, index in enumerate(special_nodes)
}
distance_matrix = [[0 for _ in range(N_TSP)] for _ in range(N_TSP)]
# print(special_nodes)
# upper_bound = 2**31
for i in range(N_TSP):
for j in range(N_TSP):
if i != j:
edge_weight = int(
round(shortest_lengths[dict_TSP_index_to_index[i]][
dict_TSP_index_to_index[j]] + 1))
# distance_matrix[i][j] = min(edge_weight, upper_bound)
distance_matrix[i][j] = edge_weight
else:
distance_matrix[i][j] = 0
# print(distance_matrix)
# run TSP concorde
matrix_sym = atsp_tsp(distance_matrix, strategy="avg")
outf = "/tmp/myroute.tsp"
with open(outf, 'w') as dest:
dest.write(dumps_matrix(matrix_sym, name="My Route"))
try:
tour = run(outf,
start=dict_index_to_TSP_index[starting_kingdom_index],
solver="lkh")
# convert to original indices
tour_G = [
dict_TSP_index_to_index[TSP_index] for TSP_index in tour["tour"]
]
# print(tour_G)
# stitch path together
edge_list = tour_to_list_of_edges(tour_G)
# print(edge_list)
stiched_tour = [edge_list[0][0]] # starting node
edge_list.append((edge_list[-1][1], starting_kingdom_index))
for i, j in edge_list:
stiched_tour.extend(shortest_paths[i][j][1:])
closed_walk = [
dict_kingdom_index_to_name[index] for index in stiched_tour
]
except:
closed_walk = "Error"
# print(closed_walk)
return closed_walk
def tsp(self, start_coord):
out_f = "./tsp_dist.tsp"
with open(out_f, 'w') as dest:
dest.write(dumps_matrix(self.dist_matrix, name="TSP_Route"))
tour = run(out_f, start=self.back_coords[start_coord], solver="lkh")
return tour
def solve(list_of_kingdom_names,
starting_kingdom,
adjacency_matrix,
params=[]):
"""
Write your algorithm here.
Input:
list_of_kingdom_names: An list of kingdom names such that node i of the graph corresponds to name index i in the list
starting_kingdom: The name of the starting kingdom for the walk
adjacency_matrix: The adjacency matrix from the input file
Output:
Return 2 things. The first is a list of kingdoms representing the walk, and the second is the set of kingdoms that are conquered
"""
split_size = 15
subgraph = nx.Graph()
last_node = None
starting_status = [0 for _ in list_of_kingdom_names]
sublist = []
starting_index = list_of_kingdom_names.index(starting_kingdom)
N = len(list_of_kingdom_names)
H = adjacency_matrix_to_graph(adjacency_matrix)
result = []
closed_walk, conquered_kingdoms = [], []
stack = []
known = set()
stack.append((None, starting_index))
while stack:
prev, node = stack.pop()
if node in known:
continue
sublist.append(node)
known.add(node)
flag = False
if len(sublist) == 1:
subgraph.add_node(0)
elif prev in sublist:
subgraph.add_edge(sublist.index(prev),
len(sublist) - 1,
weight=H[prev][node]['weight'])
else:
flag = True
sublist.pop()
if flag or len(sublist) == split_size or len(known) == N:
sub_starting_status = [starting_status[node] for node in sublist]
sub_result = solver_helper(sublist, subgraph, sub_starting_status,
adjacency_matrix)
for i in range(len(sub_result)):
if sub_result[i] == 2:
conquered_kingdoms.append(sublist[i])
for nbr in H.adj[sublist[i]]:
starting_status[nbr] = 1
subgraph = nx.Graph()
sublist = []
if flag:
subgraph.add_node(0)
sublist.append(node)
# Need to fix the order the neigbhors being added: too costly
adjs = list(H.adj[node])
avg = sum([H[node][nbr]['weight'] for nbr in adjs]) / len(adjs)
adjs = sorted(adjs,
key=lambda nbr: abs(H[node][nbr]['weight'] - avg),
reverse=True)
for nbr in adjs:
stack.append((node, nbr))
if sublist != []:
sub_starting_status = [starting_status[node] for node in sublist]
sub_result = solver_helper(sublist, subgraph, sub_starting_status,
adjacency_matrix)
for i in range(len(sub_result)):
if sub_result[i] == 2:
conquered_kingdoms.append(sublist[i])
tmp_conquered = [(-adjacency_matrix[c][c], c) for c in conquered_kingdoms]
while tmp_conquered != []:
c = heappop(tmp_conquered)[1]
conquered_kingdoms.remove(c)
if not nx.is_dominating_set(H, conquered_kingdoms):
conquered_kingdoms.append(c)
conquered = list(conquered_kingdoms)
if starting_index not in conquered:
conquered.append(starting_index)
C = len(conquered)
if C == 1:
return [starting_kingdom], [starting_kingdom]
elif C == 2:
if starting_index == conquered[0]:
start, next = conquered
else:
next, start = conquered
_, path = nx.bidirectional_dijkstra(H, start, next)
path = [list_of_kingdom_names[c] for c in path]
return path + path[::-1][1:], [
list_of_kingdom_names[c] for c in conquered_kingdoms
]
else:
matrix = np.zeros((C, C))
paths = dict()
for i in range(C):
for j in range(i + 1, C):
matrix[i, j], path = nx.bidirectional_dijkstra(
H, conquered[i], conquered[j])
paths[(i, j)] = path
paths[(j, i)] = path[::-1]
matrix = matrix + matrix.T
if np.max(matrix) >= 10e6:
matrix = matrix / 10e6
outf = "/tmp/myroute.tsp"
with open(outf, 'w') as dest:
dest.write(dumps_matrix(matrix, name="My Route"))
tour = run(outf, start=conquered.index(starting_index), solver="LKH")
tour_path = tour['tour']
for i in range(len(tour_path)):
cur = tour_path[i]
if i == len(tour_path) - 1:
dest = conquered.index(starting_index)
else:
dest = tour_path[i + 1]
closed_walk.append(paths[(cur, dest)])
final_walk = []
for i in range(len(closed_walk)):
data = closed_walk[i]
if i == 0:
for j in data:
final_walk.append(list_of_kingdom_names[j])
else:
for j in data[1:]:
final_walk.append(list_of_kingdom_names[j])
return final_walk, [
list_of_kingdom_names[c] for c in conquered_kingdoms
]
from pytsp import atsp_tsp, run, dumps_matrix
# import os
if __name__ == "__main__":
matrix = [[0, 2910, 4693], [2903, 0, 5839], [4695, 5745, 0]]
matrix_sym = atsp_tsp(matrix, strategy="avg")
# path = os.path.abspath("cs170-proj")
outf = "/tmp/myroute.tsp"
with open(outf, 'w') as dest:
dest.write(dumps_matrix(matrix_sym, name="My Route"))
tour = run(outf, start=1, solver="concorde")
print(tour)
def optimal_tour(features, mode, profile, out_points, solver):
"""
A command line interface for solving the traveling salesman problem
Input geojson features with point geometries
and output the optimal tour as geojson feature collection.
\b
$ optimal_tour waypoints.geojson | geojson-summary
19 points and 1 line
If using geodesic or directions modes, input must be in lonlat coordinates
Directions mode requires a Mapbox account and a valid token set as
the MAPBOX_ACCESS_TOKEN environment variable.
"""
log("Get point features")
features = [f for f in features if f['geometry']['type'] == 'Point']
if len(features) <= 2:
raise click.UsageError(
"Need at least 3 point features to create route")
if mode != 'cartesian' and not is_lonlat(features):
raise click.UsageError(
"For this {} mode, input must be in lonlat coordinates".format(
mode))
log("Create travel cost matrix")
if mode == 'cartesian':
matrix = local_matrix(features, 'cartesian')
elif mode == 'geodesic':
matrix = local_matrix(features, 'geodesic')
elif mode == 'directions':
dist_api = mapbox.Distance()
res = dist_api.distances(features, profile=profile)
if res.status_code == 200:
matrix = res.json()['durations']
else:
raise Exception(
"Got a {0} error from the Distances API: {1}".format(
res.status_code, res.content))
log("Prep data")
matrix_sym = atsp_tsp(matrix, strategy="avg")
outf = "/tmp/myroute.tsp"
with open(outf, 'w') as dest:
dest.write(dumps_matrix(matrix_sym, name="My Route"))
log("Run TSP solver")
tour = run(outf, start=0, solver=solver)
order = tour['tour']
features_ordered = [features[i] for i in order]
log("Create lines connecting the tour")
if mode == 'directions':
# gather geojson linestring features along actual route via directions
directions_api = mapbox.Directions()
route_features = []
for chunk in split_overlap(features_ordered + [features_ordered[0]],
24):
res = directions_api.directions(chunk, profile='mapbox.' + profile)
if res.status_code == 200:
route_features.append(res.geojson()['features'][0])
else:
raise Exception(
"Got a {0} error from the Directions API: {1}".format(
res.status_code, res.content))
else:
# Alternative, straight line distance between points
route_coords = [f['geometry']['coordinates'] for f in features_ordered]
route_coords.append(features_ordered[0]['geometry']['coordinates'])
route_features = [{
'type': 'Feature',
'properties': {
'tour': tour
},
'geometry': {
'type': 'LineString',
'coordinates': route_coords
}
}]
# meld into one geojson feature collection
log("Output feature collection")
out_features = route_features
if out_points:
out_features += features_ordered
collection = {'type': 'FeatureCollection', 'features': out_features}
click.echo(json.dumps(collection))