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authorMartial Simon <msimon_fr@hotmail.com>2025-09-15 01:07:58 +0200
committerMartial Simon <msimon_fr@hotmail.com>2025-09-15 01:07:58 +0200
commit967be9e750221ab2ab783f95df79bb26d290a45e (patch)
tree6802900a5e975f9f68b169f0f503f040056d6952 /ero1/src/drone/postier_chinois_Martial.py
add: added projectsHEADmain
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+import parameters as params
+import itertools
+from src.helper.debug_printer import debug_print
+import networkx as nx
+import pandas as pd
+
+def postier_chinois(G, debug_mode=False):
+ """
+ Parcourt le graphe en résolvant le problème du postier chinois
+ Source: https://brooksandrew.github.io/simpleblog/articles/intro-to-graph-optimization-solving-cpp/#solving-the-chinese-postman-problem
+ Parameters:
+ G: Le graphe des routes
+ debug_mode: Logs de debug
+ Returns:
+ La liste des arêtes (routes) avec entre 2.5 et 15 cm de neige
+ """
+ gu = nx.to_undirected(G)
+ nodes_odd_degree = [v for v, d in gu.degree() if d % 2 == 1]
+ debug_print('Number of nodes of odd degree: {}'.format(len(nodes_odd_degree)), debug_mode)
+ debug_print('Number of total nodes: {}'.format(len(gu.nodes())), debug_mode)
+
+ odd_node_pairs = list(itertools.combinations(nodes_odd_degree, 2))
+ debug_print('Number of odd degree node pairs: {}'.format(len(odd_node_pairs)), debug_mode)
+
+ def get_shortest_paths_distances(graph, pairs, edge_weight_name):
+ """
+ Compute shortest distance between each pair of nodes in a graph. Return a dictionary keyed on node pairs (tuples).
+ """
+ distances = {}
+ for pair in pairs:
+ distances[pair] = nx.dijkstra_path_length(graph, pair[0], pair[1], weight=edge_weight_name)
+ return distances
+ odd_node_pairs_shortest_paths = get_shortest_paths_distances(gu, odd_node_pairs, 'length')
+
+ def create_complete_graph(pair_weights, flip_weights=True):
+ """
+ Create a completely connected graph using a list of vertex pairs and the shortest path distances between them
+ Parameters:
+ pair_weights: list[tuple] from the output of get_shortest_paths_distances
+ flip_weights: Boolean. Should we negate the edge attribute in pair_weights?
+ """
+ g = nx.Graph()
+ for k, v in pair_weights.items():
+ wt_i = - v if flip_weights else v
+ # g.add_edge(k[0], k[1], {'distance': v, 'weight': wt_i}) # deprecated after NX 1.11
+ g.add_edge(k[0], k[1], **{'distance': v, 'weight': wt_i})
+ return g
+ g_odd_complete = create_complete_graph(odd_node_pairs_shortest_paths, flip_weights=True)
+ debug_print('Number of nodes in complete graph of odd nodes: {}'.format(len(g_odd_complete.nodes())), debug_mode)
+ debug_print('Number of edges in complete graph of odd nodes: {}'.format(len(g_odd_complete.edges())), debug_mode)
+
+ odd_matching_dupes = nx.algorithms.max_weight_matching(g_odd_complete, True)
+ odd_matching = list(pd.unique([tuple(sorted([k, v])) for k, v in odd_matching_dupes]))
+ debug_print('Number of edges in max weight matching: {}'.format(len(odd_matching)), debug_mode)
+
+ def add_augmenting_path_to_graph(graph, min_weight_pairs):
+ """
+ Add the min weight matching edges to the original graph
+ Parameters:
+ graph: NetworkX graph (original graph from trailmap)
+ min_weight_pairs: list[tuples] of node pairs from min weight matching
+ Returns:
+ augmented NetworkX graph
+ """
+
+ # We need to make the augmented graph a MultiGraph so we can add parallel edges
+ graph_aug = nx.MultiGraph(graph.copy())
+ for pair in min_weight_pairs:
+ graph_aug.add_edge(pair[0],
+ pair[1],
+ **{'length': nx.dijkstra_path_length(graph, pair[0], pair[1]), 'name': 'augmented'}
+ # attr_dict={'distance': nx.dijkstra_path_length(graph, pair[0], pair[1]),
+ # 'trail': 'augmented'} # deprecated after 1.11
+ )
+ return graph_aug
+ g_aug = add_augmenting_path_to_graph(gu, odd_matching)
+
+ # Counts
+ debug_print('Number of edges in original graph: {}'.format(len(gu.edges())), debug_mode)
+ debug_print('Number of edges in augmented graph: {}'.format(len(g_aug.edges())), debug_mode)
+
+ def create_eulerian_circuit(graph_augmented, graph_original):
+ """
+ Create the eulerian path using only edges from the original graph.
+ """
+ debug_print("Creating eulerian circuit", debug_mode)
+ euler_circuit = []
+ naive_circuit = list(nx.eulerian_circuit(graph_augmented))
+ dbg = False
+
+ for edge in naive_circuit:
+ edge_data = graph_augmented.get_edge_data(edge[0], edge[1])
+
+ if len(edge_data) == 1 and 'name' in edge_data[0] and edge_data[0]['name'] != 'augmented':
+ # If `edge` exists in original graph, grab the edge attributes and add to eulerian circuit.
+ edge_att = graph_original[edge[0]][edge[1]]
+ euler_circuit.append((edge[0], edge[1], edge_att))
+ else:
+ aug_path = nx.shortest_path(graph_original, edge[0], edge[1], weight='length')
+ aug_path_pairs = list(zip(aug_path[:-1], aug_path[1:]))
+
+ debug_print('Filling in edges for augmented edge: {}'.format(edge), dbg)
+ debug_print('Augmenting path: {}'.format(' => '.join(str(aug_path))), dbg)
+ debug_print('Augmenting path pairs: {}\n'.format(aug_path_pairs), dbg)
+
+ # If `edge` does not exist in original graph, find the shortest path between its nodes and
+ # add the edge attributes for each link in the shortest path.
+ for edge_aug in aug_path_pairs:
+ edge_aug_att = graph_original[edge_aug[0]][edge_aug[1]]
+ euler_circuit.append((edge_aug[0], edge_aug[1], edge_aug_att))
+
+ return euler_circuit
+ euler_circuit = create_eulerian_circuit(g_aug, gu)
+ debug_print('Length of Eulerian circuit: {}'.format(len(euler_circuit)), debug_mode)
+
+ debug_print("Extraction des la météo des neiges depuis le parcours eulérien...", debug_mode)
+
+ routes_enneigées = []
+ for edge in euler_circuit:
+ if params.SNOW_THRESHOLD <= edge[2][0]['snow'] <= params.SNOW_MAX:
+ routes_enneigées.append(edge)
+ return routes_enneigées \ No newline at end of file