Source code for gemseo_umdo.use_cases.spring_mass_model.discipline

# Copyright 2021 IRT Saint Exupéry, https://www.irt-saintexupery.com
#
# This program is free software; you can redistribute it and/or
# modify it under the terms of the GNU Lesser General Public
# License version 3 as published by the Free Software Foundation.
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# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
# Lesser General Public License for more details.
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"""The spring-mass model use case."""
from __future__ import annotations

from typing import Final

from gemseo.core.discipline import MDODiscipline
from numpy import array

from gemseo_umdo.use_cases.spring_mass_model.model import SpringMassModel


[docs]class SpringMassDiscipline(MDODiscipline): r"""The |g|-based spring-mass model :math:`m\frac{d^2z(t)}{dt^2} = -kz(t) + mg`. This model computes the time displacement of an object attached to a spring in function of the stiffness of the spring. It computes also its maximum displacement. """ __STIFFNESS: Final[str] = "stiffness" __DISPLACEMENT: Final[str] = "displacement" __MAX_DISPLACEMENT: Final[str] = "max_displacement" def __init__( self, mass: float = 1.5, initial_state: tuple[float, float] = (0, 0), initial_time: float = 0.0, final_time: float = 10.0, time_step: float = 0.1, gravity: float = 9.8, ) -> None: """ Args: mass: The mass of the object. initial_state: The initial position and velocity of the object. initial_time: The initial time. final_time: The final time. time_step: The time step. gravity: The gravity acceleration. """ # noqa: D205 D212 D415 super().__init__(name=f"{self.__class__.__name__}({time_step})") self.input_grammar.update([self.__STIFFNESS]) self.output_grammar.update([self.__MAX_DISPLACEMENT, self.__DISPLACEMENT]) self.__model = SpringMassModel( mass=mass, initial_state=initial_state, initial_time=initial_time, final_time=final_time, time_step=time_step, gravity=gravity, ) self.default_inputs = {self.__STIFFNESS: array([2.25])} def _run(self) -> None: disp, max_disp = self.__model(self.local_data[self.__STIFFNESS][0]) self._local_data[self.__DISPLACEMENT] = disp self._local_data[self.__MAX_DISPLACEMENT] = array([max_disp]) @property def cost(self) -> float: """The evaluation cost.""" return self.__model.cost