.. DO NOT EDIT. .. THIS FILE WAS AUTOMATICALLY GENERATED BY SPHINX-GALLERY. .. TO MAKE CHANGES, EDIT THE SOURCE PYTHON FILE: .. "examples/mdo/plot_gemseo_in_10_minutes.py" .. LINE NUMBERS ARE GIVEN BELOW. .. only:: html .. note:: :class: sphx-glr-download-link-note Click :ref:`here ` to download the full example code .. rst-class:: sphx-glr-example-title .. _sphx_glr_examples_mdo_plot_gemseo_in_10_minutes.py: |g| in 10 minutes ============================= .. _gemseo_10min: .. GENERATED FROM PYTHON SOURCE LINES 27-40 Introduction ------------ This is a short introduction to |g|, geared mainly for new users. In this example, we will set up a simple Multi-disciplinary Design Optimization (:term:`MDO`) problem based on a simple analytic problem. Imports ------- First, we will import all the classes and functions needed for the tutorials. The first imports (__future__ and future) enable to run the tutorial using either a Python 2 or a Python 3 interpreter. .. GENERATED FROM PYTHON SOURCE LINES 41-51 .. code-block:: default from math import exp from gemseo.api import configure_logger from gemseo.api import create_design_space from gemseo.api import create_discipline from gemseo.api import create_scenario from matplotlib import pyplot as plt from numpy import array from numpy import ones .. GENERATED FROM PYTHON SOURCE LINES 52-54 Finally, the following functions from the |g| API are imported. They will be used latter in order to instantiate |g| objects. .. GENERATED FROM PYTHON SOURCE LINES 54-57 .. code-block:: default configure_logger() .. rst-class:: sphx-glr-script-out Out: .. code-block:: none .. GENERATED FROM PYTHON SOURCE LINES 58-63 These imports enables to compute mathematical expressions, as well to instantiate numpy arrays. Numpy arrays are used to store numerical data in |g| at low level. If you are not confortable with using Numpy, please have a look at the `Numpy Quickstart tutorial `_. .. GENERATED FROM PYTHON SOURCE LINES 66-81 A simple MDO test case: the Sellar Problem ------------------------------------------ We will consider in this example the Sellar's problem: .. include:: /tutorials/_description/sellar_problem_definition.inc Definition of the disciplines using Python functions ---------------------------------------------------- The Sellar's problem is composed of two :term:`disciplines ` and an :term:`objective function`. As they are expressed analytically, it is possible to write them as simple Python functions which take as parameters the :term:`design variables` and the :term:`coupling variables`. The returned values may be the outputs of a discipline, the values of the :term:`constraints` or the value of the objective function. Their definitions read: .. GENERATED FROM PYTHON SOURCE LINES 82-104 .. code-block:: default def f_sellar_system(x_local=1.0, x_shared_2=3.0, y_1=1.0, y_2=1.0): """Objective function.""" obj = x_local**2 + x_shared_2 + y_1**2 + exp(-y_2) c_1 = 3.16 - y_1**2 c_2 = y_2 - 24.0 return obj, c_1, c_2 def f_sellar_1(x_local=1.0, y_2=1.0, x_shared_1=1.0, x_shared_2=3.0): """Function for discipline 1.""" y_1 = (x_shared_1**2 + x_shared_2 + x_local - 0.2 * y_2) ** 0.5 return y_1 def f_sellar_2(y_1=1.0, x_shared_1=1.0, x_shared_2=3.0): """Function for discipline 2.""" y_2 = abs(y_1) + x_shared_1 + x_shared_2 return y_2 .. GENERATED FROM PYTHON SOURCE LINES 105-113 These Python functions can be easily converted into |g| :class:`.MDODiscipline` objects by using the :class:`.AutoPyDiscipline` discipline. It enables the automatic wrapping of a Python function into a |g| :class:`.MDODiscipline` by only passing a reference to the function to be wrapped. |g| handles the wrapping and the grammar creation under the hood. The :class:`.AutoPyDiscipline` discipline can be instantiated using the :func:`.create_discipline` function from the |g| :term:`API`: .. GENERATED FROM PYTHON SOURCE LINES 113-120 .. code-block:: default disc_sellar_system = create_discipline("AutoPyDiscipline", py_func=f_sellar_system) disc_sellar_1 = create_discipline("AutoPyDiscipline", py_func=f_sellar_1) disc_sellar_2 = create_discipline("AutoPyDiscipline", py_func=f_sellar_2) .. GENERATED FROM PYTHON SOURCE LINES 121-126 Note that it is possible to define the Sellar disciplines by subclassing the :class:`.MDODiscipline` class and implementing the constuctor and the _run method by hand. Although it would take more time, it may also provide more flexibily and more options. This method is illustrated in the :ref:`Sellar from scratch tutorial `. .. GENERATED FROM PYTHON SOURCE LINES 126-131 .. code-block:: default # We then create a list of disciplines, which will be used later to create an # :class:`.MDOScenario`: disciplines = [disc_sellar_system, disc_sellar_1, disc_sellar_2] .. GENERATED FROM PYTHON SOURCE LINES 132-139 .. note:: For the sake of clarity, these disciplines are overly simple. Yet, |g| enables the definition of much more complex disciplines, such as wrapping complex :term:`COTS`. Check out the other :ref:`tutorials ` and our :ref:`publications list ` for more information. .. GENERATED FROM PYTHON SOURCE LINES 141-146 Definition of the design space ------------------------------ In order to define :class:`.MDOScenario`, a :term:`design space` has to be defined by creating a :class:`.DesignSpace` object. The design space definition reads: .. GENERATED FROM PYTHON SOURCE LINES 146-154 .. code-block:: default design_space = create_design_space() design_space.add_variable("x_local", 1, l_b=0.0, u_b=10.0, value=ones(1)) design_space.add_variable("x_shared_1", 1, l_b=-10, u_b=10.0, value=array([4.0])) design_space.add_variable("x_shared_2", 1, l_b=0.0, u_b=10.0, value=array([3.0])) design_space.add_variable("y_1", 1, l_b=-100.0, u_b=100.0, value=ones(1)) design_space.add_variable("y_2", 1, l_b=-100.0, u_b=100.0, value=ones(1)) .. GENERATED FROM PYTHON SOURCE LINES 155-163 Definition of the MDO scenario ------------------------------ Once the disciplines and the design space have been defined, we can create our MDO scenario by using the :func:`.create_scenario` API call. In this simple example, we are using a Multiple Disciplinary Feasible (:term:`MDF`) strategy. The Multiple Disciplinary Analyses (:term:`MDA`) are carried out using the Gauss-Seidel method. The scenario definition reads: .. GENERATED FROM PYTHON SOURCE LINES 163-172 .. code-block:: default scenario = create_scenario( disciplines, formulation="MDF", inner_mda_name="MDAGaussSeidel", objective_name="obj", design_space=design_space, ) .. GENERATED FROM PYTHON SOURCE LINES 173-197 It can be noted that neither a :term:`workflow ` nor a :term:`dataflow ` has been defined. By design, there is no need to explicitely define the workflow and the dataflow in |g|: - the workflow is determined from the MDO formulation used. - the dataflow is determined from the variable names used in the disciplines. Then, it is of uttermost importance to be consistent while choosing and using the variable names in the disciplines. .. warning:: As the workflow and the dataflow are implicitely determined by |g|, set-up errors may easily occur. Although it is not performed in this example, it is strongly advised to - check the interfaces between the several disciplines using an N2 diagram, - check the MDO process using an XDSM representation Setting the constraints ----------------------- Most of the MDO problems are under :term:`constraints`. In our problem, we have two inequality constraints, and their declaration reads: .. GENERATED FROM PYTHON SOURCE LINES 197-201 .. code-block:: default scenario.add_constraint("c_1", "ineq") scenario.add_constraint("c_2", "ineq") .. GENERATED FROM PYTHON SOURCE LINES 202-209 Execution of the scenario ------------------------- The scenario is now complete and ready to be executed. When running the optimization process, the user can choose the optimization algorithm and the maximum number of iterations to perform. The execution of the scenario reads: .. GENERATED FROM PYTHON SOURCE LINES 209-212 .. code-block:: default scenario.execute(input_data={"max_iter": 10, "algo": "SLSQP"}) .. rst-class:: sphx-glr-script-out Out: .. code-block:: none INFO - 07:18:22: INFO - 07:18:22: *** Start MDOScenario execution *** INFO - 07:18:22: MDOScenario INFO - 07:18:22: Disciplines: f_sellar_system f_sellar_1 f_sellar_2 INFO - 07:18:22: MDO formulation: MDF INFO - 07:18:22: Optimization problem: INFO - 07:18:22: minimize obj(x_local, x_shared_1, x_shared_2) INFO - 07:18:22: with respect to x_local, x_shared_1, x_shared_2 INFO - 07:18:22: subject to constraints: INFO - 07:18:22: c_1(x_local, x_shared_1, x_shared_2) <= 0.0 INFO - 07:18:22: c_2(x_local, x_shared_1, x_shared_2) <= 0.0 INFO - 07:18:22: over the design space: INFO - 07:18:22: +------------+-------------+-------+-------------+-------+ INFO - 07:18:22: | name | lower_bound | value | upper_bound | type | INFO - 07:18:22: +------------+-------------+-------+-------------+-------+ INFO - 07:18:22: | x_local | 0 | 1 | 10 | float | INFO - 07:18:22: | x_shared_1 | -10 | 4 | 10 | float | INFO - 07:18:22: | x_shared_2 | 0 | 3 | 10 | float | INFO - 07:18:22: +------------+-------------+-------+-------------+-------+ INFO - 07:18:22: Solving optimization problem with algorithm SLSQP: INFO - 07:18:22: ... 0%| | 0/10 [00:00`. .. GENERATED FROM PYTHON SOURCE LINES 273-278 .. code-block:: default scenario.post_process("OptHistoryView", save=False, show=False) # Workaround for HTML rendering, instead of ``show=True`` plt.show() .. rst-class:: sphx-glr-horizontal * .. image-sg:: /examples/mdo/images/sphx_glr_plot_gemseo_in_10_minutes_001.png :alt: Evolution of the optimization variables :srcset: /examples/mdo/images/sphx_glr_plot_gemseo_in_10_minutes_001.png :class: sphx-glr-multi-img * .. image-sg:: /examples/mdo/images/sphx_glr_plot_gemseo_in_10_minutes_002.png :alt: Evolution of the objective value :srcset: /examples/mdo/images/sphx_glr_plot_gemseo_in_10_minutes_002.png :class: sphx-glr-multi-img * .. image-sg:: /examples/mdo/images/sphx_glr_plot_gemseo_in_10_minutes_003.png :alt: Distance to the optimum :srcset: /examples/mdo/images/sphx_glr_plot_gemseo_in_10_minutes_003.png :class: sphx-glr-multi-img * .. image-sg:: /examples/mdo/images/sphx_glr_plot_gemseo_in_10_minutes_004.png :alt: Hessian diagonal approximation :srcset: /examples/mdo/images/sphx_glr_plot_gemseo_in_10_minutes_004.png :class: sphx-glr-multi-img * .. image-sg:: /examples/mdo/images/sphx_glr_plot_gemseo_in_10_minutes_005.png :alt: Evolution of the inequality constraints :srcset: /examples/mdo/images/sphx_glr_plot_gemseo_in_10_minutes_005.png :class: sphx-glr-multi-img .. GENERATED FROM PYTHON SOURCE LINES 279-284 .. note:: Such post-processings can be exported in PDF format, by setting :code:`save` to :code:`True` and potentially additional settings (see the :meth:`.Scenario.post_process` options). .. GENERATED FROM PYTHON SOURCE LINES 286-292 What's next? ------------ You have completed a short introduction to |g|. You can now look at the :ref:`tutorials ` which exhibit more complex use-cases. You can also have a look at the documentation to discover the several features and options of |g|. .. rst-class:: sphx-glr-timing **Total running time of the script:** ( 0 minutes 1.425 seconds) .. _sphx_glr_download_examples_mdo_plot_gemseo_in_10_minutes.py: .. only :: html .. container:: sphx-glr-footer :class: sphx-glr-footer-example .. container:: sphx-glr-download sphx-glr-download-python :download:`Download Python source code: plot_gemseo_in_10_minutes.py ` .. container:: sphx-glr-download sphx-glr-download-jupyter :download:`Download Jupyter notebook: plot_gemseo_in_10_minutes.ipynb ` .. only:: html .. rst-class:: sphx-glr-signature `Gallery generated by Sphinx-Gallery `_