MDF-based DOE on the Sobieski SSBJ test case

from __future__ import division, unicode_literals

from matplotlib import pyplot as plt

from gemseo.api import configure_logger, create_discipline, create_scenario
from gemseo.problems.sobieski.core import SobieskiProblem

configure_logger()

Out:

<RootLogger root (INFO)>

Instantiate the disciplines

First, we instantiate the four disciplines of the use case: SobieskiPropulsion, SobieskiAerodynamics, SobieskiMission and SobieskiStructure.

disciplines = create_discipline(
    [
        "SobieskiPropulsion",
        "SobieskiAerodynamics",
        "SobieskiMission",
        "SobieskiStructure",
    ]
)

Build, execute and post-process the scenario

Then, we build the scenario which links the disciplines with the formulation and the optimization algorithm. Here, we use the BiLevel formulation. We tell the scenario to minimize -y_4 instead of minimizing y_4 (range), which is the default option.

We need to define the design space.

design_space = SobieskiProblem().read_design_space()

Instantiate the scenario

scenario = create_scenario(
    disciplines,
    formulation="MDF",
    objective_name="y_4",
    design_space=design_space,
    maximize_objective=True,
    scenario_type="DOE",
)

Set the design constraints

for constraint in ["g_1", "g_2", "g_3"]:
    scenario.add_constraint(constraint, "ineq")

Execute the scenario

Use provided analytic derivatives

scenario.set_differentiation_method("user")

Multiprocessing

It is possible to run a DOE in parallel using multiprocessing, in order to do this, we specify the number of processes to be used for the computation of the samples.

Warning

The multiprocessing option has some limitations on Windows. For Python versions < 3.7 and Numpy < 1.20.0, subprocesses may get hung randomly during execution. It is strongly recommended to update your environment to avoid this problem. The features MemoryFullCache and HDF5Cache are not available for multiprocessing on Windows. As an alternative, we recommend the method DOEScenario.set_optimization_history_backup().

n_processes = 4

We define the algorithm options. Here the criterion = center option of pyDOE centers the points within the sampling intervals.

algo_options = {
    "criterion": "center",
    # Evaluate gradient of the MDA
    # with coupled adjoint
    "eval_jac": True,
    # Run in parallel on 4 processors
    "n_processes": n_processes,
}
run_inputs = {"n_samples": 30, "algo": "lhs", "algo_options": algo_options}

Warning

When running a parallel DOE on Windows, the execution must be protected to avoid recursive calls:

if __name__ == "__main__":
    scenario.execute(run_inputs)

Out:

INFO - 14:42:59:
INFO - 14:42:59: *** Start DOE Scenario execution ***
INFO - 14:42:59: DOEScenario
INFO - 14:42:59:    Disciplines: SobieskiPropulsion SobieskiAerodynamics SobieskiMission SobieskiStructure
INFO - 14:42:59:    MDOFormulation: MDF
INFO - 14:42:59:    Algorithm: lhs
INFO - 14:42:59: Optimization problem:
INFO - 14:42:59:    Minimize: -y_4(x_shared, x_1, x_2, x_3)
INFO - 14:42:59:    With respect to: x_shared, x_1, x_2, x_3
INFO - 14:42:59:    Subject to constraints:
INFO - 14:42:59:       g_1(x_shared, x_1, x_2, x_3) <= 0.0
INFO - 14:42:59:       g_2(x_shared, x_1, x_2, x_3) <= 0.0
INFO - 14:42:59:       g_3(x_shared, x_1, x_2, x_3) <= 0.0
INFO - 14:42:59: DOE sampling:   0%|          | 0/30 [00:00<?, ?it]
INFO - 14:42:59: Running DOE in parallel on n_processes = 4
INFO - 14:42:59: DOE sampling:   3%|▎         | 1/30 [00:00<00:00, 65.28 it/sec, obj=285]
INFO - 14:42:59: DOE sampling:  13%|█▎        | 4/30 [00:00<00:00, 45.71 it/sec, obj=344]
INFO - 14:42:59: DOE sampling:  17%|█▋        | 5/30 [00:00<00:00, 37.71 it/sec, obj=235]
INFO - 14:42:59: DOE sampling:  23%|██▎       | 7/30 [00:00<00:00, 32.63 it/sec, obj=429]
INFO - 14:43:00: DOE sampling:  30%|███       | 9/30 [00:01<00:00, 26.89 it/sec, obj=538]
INFO - 14:43:00: DOE sampling:  37%|███▋      | 11/30 [00:01<00:00, 23.43 it/sec, obj=306]
INFO - 14:43:00: DOE sampling:  43%|████▎     | 13/30 [00:01<00:00, 21.35 it/sec, obj=556]
INFO - 14:43:00: DOE sampling:  50%|█████     | 15/30 [00:01<00:00, 18.26 it/sec, obj=481]
INFO - 14:43:00: DOE sampling:  60%|██████    | 18/30 [00:01<00:00, 16.00 it/sec, obj=1.07e+3]
INFO - 14:43:01: DOE sampling:  67%|██████▋   | 20/30 [00:02<00:00, 14.87 it/sec, obj=602]
INFO - 14:43:01: DOE sampling:  73%|███████▎  | 22/30 [00:02<00:00, 13.32 it/sec, obj=1.18e+3]
INFO - 14:43:01: DOE sampling:  83%|████████▎ | 25/30 [00:02<00:00, 12.54 it/sec, obj=624]
INFO - 14:43:01: DOE sampling:  90%|█████████ | 27/30 [00:02<00:00, 11.37 it/sec, obj=606]
INFO - 14:43:01: DOE sampling:  97%|█████████▋| 29/30 [00:02<00:00, 10.88 it/sec, obj=485]
INFO - 14:43:01: DOE sampling: 100%|██████████| 30/30 [00:02<00:00, 10.66 it/sec, obj=405]
INFO - 14:43:01: Optimization result:
INFO - 14:43:01: Objective value = 485.49220045924955
INFO - 14:43:01: The result is feasible.
INFO - 14:43:01: Status: None
INFO - 14:43:01: Optimizer message: None
INFO - 14:43:01: Number of calls to the objective function by the optimizer: 30
INFO - 14:43:01: Constraints values:
INFO - 14:43:01:    g_1 = [-0.11350951 -0.10812292 -0.1045109  -0.10204971 -0.10028641 -0.01838903
INFO - 14:43:01:  -0.22161097]
INFO - 14:43:01:    g_2 = -0.02400000000000002
INFO - 14:43:01:    g_3 = [-0.33063157 -0.66936843 -0.73821755 -0.07789536]
INFO - 14:43:01: Design space:
INFO - 14:43:01: +----------+-------------+---------------------+-------------+-------+
INFO - 14:43:01: | name     | lower_bound |        value        | upper_bound | type  |
INFO - 14:43:01: +----------+-------------+---------------------+-------------+-------+
INFO - 14:43:01: | x_shared |     0.01    | 0.05400000000000001 |     0.09    | float |
INFO - 14:43:01: | x_shared |    30000    |        46500        |    60000    | float |
INFO - 14:43:01: | x_shared |     1.4     |  1.686666666666667  |     1.8     | float |
INFO - 14:43:01: | x_shared |     2.5     |         5.2         |     8.5     | float |
INFO - 14:43:01: | x_shared |      40     |         66.5        |      70     | float |
INFO - 14:43:01: | x_shared |     500     |  583.3333333333334  |     1500    | float |
INFO - 14:43:01: | x_1      |     0.1     |        0.185        |     0.4     | float |
INFO - 14:43:01: | x_1      |     0.75    |  0.9416666666666667 |     1.25    | float |
INFO - 14:43:01: | x_2      |     0.75    |        0.775        |     1.25    | float |
INFO - 14:43:01: | x_3      |     0.1     |        0.115        |      1      | float |
INFO - 14:43:01: +----------+-------------+---------------------+-------------+-------+
INFO - 14:43:01: *** DOE Scenario run terminated ***

Warning

On Windows, the progress bar may show duplicated instances during the initialization of each subprocess. In some cases it may also print the conclusion of an iteration ahead of another one that was concluded first. This is a consequence of the pickling process and does not affect the computations of the scenario.

Plot the optimization history view

scenario.post_process("OptHistoryView", show=False, save=False)
  • Evolution of the optimization variables
  • Evolution of the objective value
  • Distance to the optimum
  • Hessian diagonal approximation
  • Evolution of the inequality constraints

Out:

<gemseo.post.opt_history_view.OptHistoryView object at 0x7f3b51f2afa0>

Tip

Each post-processing method requires different inputs and offers a variety of customization options. Use the API function get_post_processing_options_schema() to print a table with the attributes for any post-processing algo. Or refer to our dedicated page: Options for Post-processing algorithms.

Plot the scatter matrix

scenario.post_process(
    "ScatterPlotMatrix", show=False, save=False, variables_list=["y_4", "x_shared"]
)
plot doe sobieski mdf example

Out:

<gemseo.post.scatter_mat.ScatterPlotMatrix object at 0x7f3b51dac610>

Plot correlations

scenario.post_process("Correlations", show=False, save=False)
# Workaround for HTML rendering, instead of ``show=True``
plt.show()
R=0.98987, R=0.97511, R=0.99671, R=0.96235, R=0.99119, R=0.99866, R=0.95205, R=0.98584, R=0.99618, R=0.99936

Out:

INFO - 14:43:04: Detected 10 correlations > 0.95

Total running time of the script: ( 0 minutes 6.263 seconds)

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