utils
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1 changed files with 50 additions and 9 deletions
59
src/utils.py
59
src/utils.py
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@ -1,3 +1,53 @@
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import numpy as np
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def compute_lenght(solution, dist_matrix):
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total_length = 0
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starting_node = solution[0]
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from_node = starting_node
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for node in solution[1:]:
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total_length += dist_matrix[from_node, node]
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from_node = node
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return total_length
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class random_initialier:
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@staticmethod
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def random_method(instance_):
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n = int(instance_.nPoints)
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solution = np.random.choice(np.arange(n), size=n, replace=False)
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return np.concatenate([solution, [solution[0]]])
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class nearest_neighbor:
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@staticmethod
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def nn(instance_, starting_node=0):
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dist_matrix = np.copy(instance_.dist_matrix)
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n = int(instance_.nPoints)
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node = starting_node
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tour = [node]
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for _ in range(n - 1):
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for new_node in np.argsort(dist_matrix[node]):
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if new_node not in tour:
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tour.append(new_node)
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node = new_node
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break
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tour.append(starting_node)
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return np.array(tour)
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@staticmethod
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def best_nn(self, instance_):
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solutions, lens = [], []
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for start in range(self.instance.nPoints):
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new_solution = self.nn(instance_, starting_node=start)
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solutions.append(new_solution)
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assert self.check_if_solution_is_valid(new_solution), "error on best_nn method"
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lens.append(self.evaluate_solution(return_value=True))
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self.solution = solutions[np.argmin(lens)]
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self.solved = True
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return self.solution
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class multi_fragment:
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@staticmethod
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@ -63,12 +113,3 @@ class multi_fragment:
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sol_list.append(n1)
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return sol_list
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def compute_lenght(solution, dist_matrix):
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total_length = 0
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starting_node = solution[0]
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from_node = starting_node
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for node in solution[1:]:
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total_length += dist_matrix[from_node, node]
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from_node = node
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return total_length
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