def run():
overall_best_front = list()
# Load seeds if specified
seeds = list()
if args.seed_file:
seeds = initializers.read_from_file(args.seed_file, equation.number_of_variables)
# Setup termination functions
terminator_functions = list()
if args.terminate_pareto != -1:
terminator = terminators.StablePareto(args.terminate_pareto)
terminator_functions.append(terminator.evaluate)
# Choose parent selection algorithm
select_parents = {
'random': parent_selectors.uniform_random(args.children),
'FPS': parent_selectors.fitness_prop_selection(args.children),
'kTourn': parent_selectors.k_tournament_with_replacement(args.children, args.parent_k)
}[args.parent_selection]
# Choose recombination function
recombine = recombination.crossover(equation.number_of_variables)
# Choose mutation function
mutate = mutations.flip_bits(equation.number_of_variables)
# Choose survival selection function
select_survivors = {
'random': survival_selectors.uniform_random(args.population_size),
'FPS': survival_selectors.fitness_prop_selection(args.population_size),
'Truncation': survival_selectors.truncate(args.population_size),
'kTourn': survival_selectors.k_tournament_without_replacement(args.population_size, args.survival_k)
}[args.survival_selection]
# Choose survival strategy
survival_strategy = {
'plus': survival_strategies.plus,
'comma': survival_strategies.comma
}[args.survival_strategy]
# Actually run the algorithm
for run_index in range(args.runs):
args.log.write('\nRun {0}\n'.format(run_index + 1))
# Generate initial population randomly and/or with seeds
individuals = initializers.initialize(args.population_size, equation.number_of_variables)
if seeds:
individuals = numpy.concatenate((individuals[:-len(seeds)], seeds))
# Calculate fitness values
pareto_indices = [0] * args.population_size
fitnesses = equation.evaluate(individuals)
simplicities = equation.count_free_variables(individuals)
# Sort population by fitness
zipped = zip(pareto_indices, fitnesses, simplicities, individuals)
fronts = pareto.generate_fronts(zipped)
zipped = pareto.generate_zipped_from_fronts(fronts)
pareto_indices, fitnesses, simplicities, individuals = zip(*zipped)
# Increment the number of evaluations that have occurred
evals = args.population_size
# Record average and best
args.log.write("{0}\t{1}\t{2}\t{3}\t{4}\n".format(evals,
float(sum(fitnesses)) / len(fitnesses), max(fitnesses),
float(sum(simplicities)) / len(simplicities), max(simplicities)))
if args.diversity:
args.diversity.write('\nRun {0}\n'.format(run_index + 1))
args.diversity.write(str(sat_core.measure(pareto.get_best_front(zipped), [1, 2], [0, 0, 0],
[0, equation.number_of_clauses,
equation.number_of_variables])) + '\n')
for generation_index in itertools.count():
sys.stdout.write('.')
# Generate children
children = [recombine((individuals[parent_indices[0]], individuals[parent_indices[1]]))
for parent_indices in select_parents(pareto_indices)]
mutate(children)
children_fitnesses = equation.evaluate(children)
children_simplicity = equation.count_free_variables(children)
evals += len(children)
children_pareto = [0] * len(children)
zipped_children = zip(children_pareto, children_fitnesses, children_simplicity, children)
# Choose survivors
zipped = survival_strategy(zipped, zipped_children, select_survivors)
pareto_indices, fitnesses, simplicities, individuals = zip(*zipped)
# Record average and best
args.log.write("{0}\t{1}\t{2}\t{3}\t{4}\n".format(evals,
float(sum(fitnesses)) / len(fitnesses), max(fitnesses),
float(sum(simplicities)) / len(simplicities), max(simplicities)))
if args.diversity:
args.diversity.write(str(sat_core.measure(pareto.get_best_front(zipped), [1, 2], [0, 0, 0],
[0, equation.number_of_clauses,
equation.number_of_variables])) + '\n')
# Check for termination
if any(terminator(zipped) for terminator in terminator_functions):
break
if args.evals != -1 and evals >= args.evals:
break
print('Best of run: {0} {1}'.format(max(x[1] for x in zipped), max(x[2] for x in zipped)))
best_front = list(pareto.get_best_front(zipped))
# Write pareto front
if args.pareto:
args.pareto.write('c Run {run_index}\n'.format(**locals()))
for solution in best_front:
args.pareto.write("c MAXSAT fitness value: {0}\n".format(solution[1]))
args.pareto.write("c Number of 'don't care' variables: {0}\n".format(solution[2]))
args.pareto.write('v {0}\n'.format(' '.join(str((i + 1) * [-1, 1][x])
for i, x in enumerate(solution[3]) if x != -1)))
# Update best of all runs
percent_better = pareto.compare_fronts(best_front, overall_best_front)
if percent_better > 0.5:
print('New best front! ({})'.format(percent_better))
overall_best_front = best_front
# Write overall best pareto front
args.solution.write("c Number of solutions in pareto front: {0}\n".format(len(overall_best_front)))
for solution in overall_best_front:
args.solution.write("c MAXSAT fitness value: {0}\n".format(solution[1]))
args.solution.write("c Number of 'don't care' variables: {0}\n".format(solution[2]))
args.solution.write('v {0}\n'.format(' '.join(str((i + 1) * [-1, 1][x])
for i, x in enumerate(solution[3]) if x != -1)))