Source code for gemseo.core.derivatives.mda_derivatives

# Copyright 2021 IRT Saint Exupéry,
# 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.
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# Lesser General Public License for more details.
# You should have received a copy of the GNU Lesser General Public License
# along with this program; if not, write to the Free Software Foundation,
# Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
# Contributors:
#    INITIAL AUTHORS - API and implementation and/or documentation
#        :author: Francois Gallard
"""Graph algorithms to solve the Jacobian accumulation problem for MDOChain and MDA."""
from __future__ import annotations

import uuid
from typing import TYPE_CHECKING

from gemseo.core.coupling_structure import MDOCouplingStructure
from gemseo.core.derivatives.chain_rule import traverse_add_diff_io
from gemseo.core.discipline import MDODiscipline

    from typing import Iterable
    from gemseo.core.derivatives.chain_rule import DisciplineIOMapping

def _replace_strongly_coupled(
    coupling_structure: MDOCouplingStructure,
) -> tuple[list[MDODiscipline], list[MDODiscipline]]:
    """Replace the strongly coupled disciplines by a single one.

    The replacing discipline has for inputs the merged inputs of all coupled
    discipline except for the strong couplings, while its outputs are all combined

        coupling_structure: The input coupling structure containing the graph and all
            the disciplines

        All the disciplines with the strongly coupled replaced by the
        merged one, and the replacing disciplines.
    disciplines_with_group = list(coupling_structure.disciplines)
    reduced_disciplines = []
    all_disc_with_red = []
    strong_c = set(coupling_structure.strong_couplings)
    for parallel_tasks in coupling_structure.sequence:
        for group in parallel_tasks:
            # The strong coupling cycles are treated here
            # And also the self coupled disciplines
            if len(group) > 1 or (
                len(group) == 1 and coupling_structure.is_self_coupled(group[0])
                disc_merged = MDODiscipline(str(uuid.uuid4()))
                for disc in group:
                    # The strong couplings are not real dependencies of the MDA for
                    # derivatives computation.
                        set(disc.input_grammar.names) - strong_c

                disc = group[0]
                # The weakly coupled disciplines are treated like in the chain.

    return all_disc_with_red, reduced_disciplines

[docs]def traverse_add_diff_io_mda( coupling_structure: MDOCouplingStructure, inputs: Iterable[str], outputs: Iterable[str], ) -> DisciplineIOMapping: """Set the required differentiated IOs for the disciplines in a chain. Add the differentiated inputs and outputs to the disciplines in a chain of of executions, given the list of inputs with respect to which the derivation is made and the list of outputs to be derived. The inputs and outputs are a subset of all the inputs and outputs of the chain. This allows to minimize the number of linearizations to perform in the disciplines. Uses a two ways (from inputs to outputs and then from outputs to inputs) breadth first search graph traversal algorithm. The graph is constructed by :class:`.DependencyGraph`, which represents the data connexions (edges) between the disciplines (nodes). Args: coupling_structure: The coupling structure of the MDA. inputs: The inputs with respect to which the chain chain is differentiated. outputs: The chain outputs to be differentiated. Returns: The merged differentiated inputs and outputs. """ strong_groups = coupling_structure.get_strongly_coupled_disciplines( by_group=True, add_self_coupled=True ) all_disc_with_red, reduced_disciplines = _replace_strongly_coupled( coupling_structure ) reduced_coupling_structure = MDOCouplingStructure(all_disc_with_red) diff_ios_merged = traverse_add_diff_io( reduced_coupling_structure.graph.graph, inputs, outputs, add_differentiated_ios=True, ) # The sub MDAs where the strong couplings are handled here. strong_couplings = coupling_structure.strong_couplings for group, disc_reduced in zip(strong_groups, reduced_disciplines): if disc_reduced in diff_ios_merged: diff_red_in = set(diff_ios_merged[disc_reduced][0]) diff_red_out = set(diff_ios_merged[disc_reduced][1]) for disc in group: # There is a need to differentiate with respect to all the inputs of # the MDA that are also inputs of the discipline # And we add all strong input couplings # Finally we keep only the discipline inputs. diff_in = diff_red_in.union(strong_couplings).intersection( disc.input_grammar.names ) disc.add_differentiated_inputs(diff_in) # It is simpler for the outputs because the outputs to be differentiated # are the ones from the MDA. diff_out = diff_red_out.union(strong_couplings).intersection( disc.output_grammar.names ) disc.add_differentiated_outputs(diff_out) diff_ios_merged[disc] = (list(diff_in), list(diff_out)) # The state variables and residuals must be differentiated too, only for the # disciplines involved in the computations. for disc, diffio_disc in diff_ios_merged.items(): if disc.residual_variables: residuals = disc.residual_variables.keys() states = disc.residual_variables.values() diffio_disc[0].extend(states) diffio_disc[1].extend(residuals) disc.add_differentiated_inputs(states) disc.add_differentiated_outputs(residuals) return diff_ios_merged