def constructor(self, random, args):
"""Return a candidate solution for an ant colony optimization."""
self._use_ants = True
candidate = []
while len(candidate) < len(self.components):
# Find feasible components
feasible_components = []
if len(candidate) == 0:
feasible_components = self.components
else:
remaining_capacity = self.capacity - sum([c.element for c in candidate])
if self.duplicates:
feasible_components = [c for c in self.components if c.element <= remaining_capacity]
else:
feasible_components = [c for c in self.components if c not in candidate and c.element <= remaining_capacity]
if len(feasible_components) == 0:
break
else:
# Choose a feasible component
if random.random() <= self.bias:
next_component = max(feasible_components)
else:
next_component = selectors.fitness_proportionate_selection(random, feasible_components, {'num_selected': 1})[0]
candidate.append(next_component)
return candidate
def constructor(self, random, args):
"""Return a candidate solution for an ant colony optimization."""
self._use_ants = True
candidate = []
while len(candidate) < len(self.weights) - 1:
# Find feasible components
feasible_components = []
if len(candidate) == 0:
feasible_components = self.components
elif len(candidate) == len(self.weights) - 1:
first = candidate[0]
last = candidate[-1]
feasible_components = [c for c in self.components if c.element[0] == last.element[1] and c.element[1] == first.element[0]]
else:
last = candidate[-1]
already_visited = [c.element[0] for c in candidate]
already_visited.extend([c.element[1] for c in candidate])
already_visited = set(already_visited)
feasible_components = [c for c in self.components if c.element[0] == last.element[1] and c.element[1] not in already_visited]
if len(feasible_components) == 0:
candidate = []
else:
# Choose a feasible component
if random.random() <= self.bias:
next_component = max(feasible_components)
else:
next_component = selectors.fitness_proportionate_selection(random, feasible_components, {'num_selected': 1})[0]
candidate.append(next_component)
return candidate
def constructor(self, random, args):
self._use_ants = True
candidate = []
remaining_capacity = []
while len(candidate) < len(self.components):
feasible_components = []
if len(candidate) == 0:
feasible_components = self.components
else:
remaining_capacity_weigth = self.capacity[0] - sum(
[c.element[0] for c in candidate])
remaining_capacity_value = self.capacity[1] - sum(
[c.element[1] for c in candidate])
if self.duplicates:
feasible_components = [
c for c in self.components
if c.element[0] <= remaining_capacity_weigth
and c.element[1] <= remaining_capacity_value
]
else:
feasible_components = [
c for c in self.components if c not in candidate
and c.element[0] <= remaining_capacity_weigth
and c.element[1] <= remaining_capacity_value
]
if len(feasible_components) == 0:
break
else:
# Choose a feasible component
if random.random() <= self.bias:
next_component = max(feasible_components)
else:
next_component = \
selectors.fitness_proportionate_selection(random, feasible_components, {'num_selected': 1})[0]
candidate.append(next_component)
return candidate
