SMPSO

SMPSO (Speed-constrained Multi-objective PSO) is a particle swarm optimization algorithm that bounds the particle velocity to avoid the swarm diverging, and uses a crowding-distance-based external archive of leaders.

from jmetal.algorithm.multiobjective.smpso import SMPSO
from jmetal.operator.mutation import PolynomialMutation
from jmetal.problem import ZDT3
from jmetal.util.archive import CrowdingDistanceArchive
from jmetal.util.solution import (
    print_function_values_to_file,
    print_variables_to_file,
)
from jmetal.util.termination_criterion import StoppingByEvaluations

if __name__ == "__main__":
    problem = ZDT3()

    max_evaluations = 25000
    algorithm = SMPSO(
        problem=problem,
        swarm_size=100,
        mutation=PolynomialMutation(
            probability=1.0 / problem.number_of_variables(), distribution_index=20
        ),
        leaders=CrowdingDistanceArchive(100),
        termination_criterion=StoppingByEvaluations(max_evaluations=max_evaluations),
    )

    algorithm.run()
    front = algorithm.result()

    # Save results to file
    print_function_values_to_file(front, "FUN." + algorithm.label)
    print_variables_to_file(front, "VAR." + algorithm.label)

    print(f"Algorithm: {algorithm.get_name()}")
    print(f"Problem: {problem.name()}")
    print(f"Computing time: {algorithm.total_computing_time}")

examples/multiobjective/smpso/ also has dynamic, preference-based (SMPSO/RP), and Spark evaluator variants.