Oscillator optimization using EA flow

This example demonstrates how to create and run a direct optimization.

It creates a direct optimization workflow for an oscillator with the Nature Inspired Optimization (Evolutionary Algorithm) using pyOptiSLang. It then explains how you can optionally save the project to a desired location.

Perform required imports

Perform the required imports.

import os
from pathlib import Path

from ansys.optislang.core import Optislang
import ansys.optislang.core.node_types as node_types
from ansys.optislang.core.nodes import DesignFlow, IntegrationNode, ParametricSystem
from ansys.optislang.core.project_parametric import (
    ComparisonType,
    ConstraintCriterion,
    DistributionType,
    MixedParameter,
    ObjectiveCriterion,
    StochasticParameter,
)

example_files_path = Path(os.environ["OSL_EXAMPLES"]) / "00_run_script" / "oscillator" / "files"

Create optiSLang instance

Create the optiSLang instance.

osl = Optislang(ini_timeout=60)
print(osl)

Create workflow

root_system = osl.application.project.root_system

# Create EA optimizer system and postprocessing

noa2: ParametricSystem = root_system.create_node(type_=node_types.NOA2)
omdb_path_slot = noa2.get_output_slots("OMDBPath")[0]

post_processing = root_system.create_node(type_=node_types.Postprocessing)

imdb_path_slot = post_processing.get_input_slots("IMDBPath")[0]
omdb_path_slot.connect_to(imdb_path_slot)

# Create oscillator

python_node: IntegrationNode = noa2.create_node(
    type_=node_types.Python2, design_flow=DesignFlow.RECEIVE_SEND
)
python_node.set_property(
    name="Path",
    value={
        "path": {
            "base_path_mode": {"value": "ABSOLUTE_PATH"},
            "split_path": {"head": "", "tail": str(example_files_path / "oscillator.py")},
        }
    },
)
python_node.set_property(name="MaxParallel", value=4)

python_node.register_location_as_parameter(
    location="m",
    reference_value={
        "kind": {"value": "scalar"},
        "scalar": {"real": 2.0, "imag": 0.0},
    },
)
python_node.register_location_as_parameter(location="k", reference_value=20)
python_node.register_location_as_parameter(
    location="D",
    reference_value={
        "kind": {"value": "scalar"},
        "scalar": {"real": 0.02, "imag": 0.0},
    },
)
python_node.register_location_as_parameter(location="Ekin", reference_value=10)

python_node.register_location_as_response(location="omega_damped", reference_value=4.47124)
python_node.register_location_as_response(location="x_max", reference_value=0.62342)


# Modify registered parameters
noa2.parameter_manager.modify_parameter(
    MixedParameter(
        name="k",
        reference_value=20.0,
        range=(10, 50),
        distribution_type=DistributionType.NORMAL,
        distribution_parameters=(20.0, 1.0),
    )
)
noa2.parameter_manager.modify_parameter(
    StochasticParameter(
        name="Ekin",
        reference_value=10.0,
        distribution_type=DistributionType.NORMAL,
        distribution_parameters=(0.02, 0.002),
    )
)

# Setup EA
noa2.criteria_manager.add_criterion(
    ObjectiveCriterion(name="obj", expression="x_max", criterion=ComparisonType.MIN)
)
noa2.criteria_manager.add_criterion(
    ConstraintCriterion(
        name="constr",
        expression="omega_damped",
        criterion=ComparisonType.LESSEQUAL,
        limit_expression="8.0",
    )
)

optimizer_settings = noa2.get_property("OptimizerSettings")
optimizer_settings["settings"]["MaxGenerations"] = 20
noa2.set_property("OptimizerSettings", optimizer_settings)

# Setup postprocessing
post_processing.set_property("PostprocessingMode", {"value": "automatic"})
post_processing.set_property("ShowPostProcessingDuringRun", False)
post_processing.set_property("WaitForPostprocessingToFinish", True)

Optionally save project

If you want to save the project to some desired location, uncomment and edit these lines:

dir_path = Path(r"<insert-desired-location>")
project_name = "oscillator_optimization_workflow.opf"
osl.application.save_as(dir_path / project_name)

Run workflow

Run the workflow created by the preceding scripts.

osl.application.project.start()
osl.application.save()

Stop and cancel project

Stop and cancel the project.

osl.dispose()

View generated workflow

This image shows the generated workflow.