Source code for gemseo.core.base_formulation
# 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.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
# 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 - initial API and implementation and/or initial
# documentation
# :author: Francois Gallard
# OTHER AUTHORS - MACROSCOPIC CHANGES
"""The base class for all formulations."""
from __future__ import annotations
import logging
from typing import Any
from typing import ClassVar
from typing import Iterable
from typing import Sequence
from typing import TYPE_CHECKING
from gemseo.algos.design_space import DesignSpace
from gemseo.core.discipline import MDODiscipline
from gemseo.core.execution_sequence import ExecutionSequence
from gemseo.core.factory import Factory
from gemseo.core.grammars.json_grammar import JSONGrammar
if TYPE_CHECKING:
from gemseo.core.scenario import Scenario
from docstring_inheritance import GoogleDocstringInheritanceMeta
from numpy import arange, copy, empty, in1d, ndarray, where, zeros
from gemseo.algos.opt_problem import OptimizationProblem
from gemseo.core.mdofunctions.function_from_discipline import FunctionFromDiscipline
from gemseo.core.mdofunctions.function_generator import MDOFunctionGenerator
from gemseo.core.mdofunctions.mdo_function import MDOFunction
LOGGER = logging.getLogger(__name__)
[docs]class BaseFormulation(metaclass=GoogleDocstringInheritanceMeta):
"""Abstract MDO formulation class to be extended in subclasses for use.
This class creates the objective function and constraints from the disciplines.
It defines the process implicitly.
By default,
- the objective function is minimized,
- the type of a constraint is equality,
- the activation value of a constraint is 0.
The link between the instances of :class:`.MDODiscipline`,
the name of the objective function
and the names of the constraints
is made with the :class:`.MDOFunctionGenerator`,
which generates instances of :class:`.MDOFunction` from the disciplines.
"""
disciplines: Sequence[MDODiscipline]
"""The disciplines of the MDO process."""
opt_problem: OptimizationProblem
"""The optimization problem generated by the formulation from the disciplines."""
_objective_name: str | Sequence[str]
"""The name of the objective function."""
_maximize_objective: bool
"""Whether to maximize the objective function."""
NAME: ClassVar[str] = "MDOFormulation"
"""The name of the MDO formulation."""
def __init__(
self,
disciplines: Sequence[MDODiscipline],
objective_name: str | Sequence[str],
design_space: DesignSpace,
maximize_objective: bool = False,
grammar_type: str = MDODiscipline.JSON_GRAMMAR_TYPE,
**options: Any,
) -> None: # pylint: disable=W0613
"""
Args:
disciplines: The disciplines.
objective_name: The name of the objective function.
If a sequence is passed, a vector objective function is created.
design_space: The design space.
maximize_objective: If True, the objective function is maximized.
grammar_type: The type of the input and output grammars,
either :attr:`.MDODiscipline.JSON_GRAMMAR_TYPE`
or :attr:`.MDODiscipline.SIMPLE_GRAMMAR_TYPE`.
**options: The options of the formulation.
"""
self.disciplines = disciplines
self._objective_name = objective_name
self.opt_problem = OptimizationProblem(design_space)
self._maximize_objective = maximize_objective
self.__grammar_type = grammar_type
@property
def _grammar_type(self) -> str:
"""The type of the input and output grammars."""
return self.__grammar_type
@property
def design_space(self) -> DesignSpace:
"""The design space on which the formulation is applied."""
return self.opt_problem.design_space
@staticmethod
def _check_add_cstr_input(
output_name: str,
constraint_type: str,
) -> list[str]:
"""Check the output name and constraint type passed to :meth:`.add_constraint`.
Args:
output_name: The name of the output to be used as a constraint.
For instance, if g_1 is given and constraint_type="eq",
g_1=0 will be added as a constraint to the optimizer.
constraint_type: The type of constraint,
either "eq" for equality constraint
or "ineq" for inequality constraint.
"""
if constraint_type not in [MDOFunction.TYPE_EQ, MDOFunction.TYPE_INEQ]:
raise ValueError(
"Constraint type must be either 'eq' or 'ineq',"
" got: %s instead" % constraint_type
)
if isinstance(output_name, list):
output_names = output_name
else:
output_names = [output_name]
return output_names
[docs] def add_constraint(
self,
output_name: str,
constraint_type: str = MDOFunction.TYPE_EQ,
constraint_name: str | None = None,
value: float | None = None,
positive: bool = False,
) -> None:
"""Add a user constraint.
A user constraint is a design constraint
in addition to the formulation specific constraints
such as the targets (a.k.a. consistency constraints) in IDF.
The strategy of repartition of constraints is defined in the formulation class.
Args:
output_name: The name of the output to be used as a constraint.
For instance, if g_1 is given and constraint_type="eq",
g_1=0 will be added as a constraint to the optimizer.
constraint_type: The type of constraint,
either "eq" for equality constraint or "ineq" for inequality constraint.
constraint_name: The name of the constraint to be stored,
If None, the name is generated from the output name.
value: The value of activation of the constraint.
If None, the value is equal to 0.
positive: If True, the inequality constraint is positive.
"""
output_names = self._check_add_cstr_input(output_name, constraint_type)
constraint = FunctionFromDiscipline(output_names, self, top_level_disc=True)
constraint.f_type = constraint_type
if constraint_name is None:
constraint.has_default_name = True
else:
constraint.name = constraint_name
constraint.has_default_name = False
self.opt_problem.add_constraint(constraint, value=value, positive=positive)
[docs] def add_observable(
self,
output_names: str | Sequence[str],
observable_name: str | None = None,
discipline: MDODiscipline | None = None,
) -> None:
"""Add an observable to the optimization problem.
The repartition strategy of the observable is defined in the formulation class.
Args:
output_names: The name(s) of the output(s) to observe.
observable_name: The name of the observable.
discipline: The discipline computing the observed outputs.
If None, the discipline is detected from inner disciplines.
"""
if isinstance(output_names, str):
output_names = [output_names]
obs_fun = FunctionFromDiscipline(
output_names, self, top_level_disc=True, discipline=discipline
)
if observable_name is not None:
obs_fun.name = observable_name
obs_fun.f_type = MDOFunction.TYPE_OBS
self.opt_problem.add_observable(obs_fun)
[docs] def get_top_level_disc(self) -> list[MDODiscipline]:
"""Return the disciplines which inputs are required to run the scenario.
A formulation seeks to
evaluate objective function and constraints from inputs.
It structures the optimization problem into multiple levels of disciplines.
The disciplines directly depending on these inputs
are called top level disciplines.
By default, this method returns all disciplines.
This method can be overloaded by subclasses.
Returns:
The top level disciplines.
"""
return self.disciplines
@staticmethod
def _get_mask_from_datanames(
all_data_names: ndarray,
masked_data_names: ndarray,
) -> ndarray:
"""Get a mask of all_data_names for masked_data_names.
This mask is an array of the size of all_data_names
with True values when masked_data_names are in all_data_names.
Args:
all_data_names: The main array for mask.
masked_data_names: The array which masks all_data_names.
Returns:
A True / False valued mask array.
"""
places = in1d(all_data_names, masked_data_names)
return where(places)
def _get_generator_from(
self,
output_names: Iterable[str],
top_level_disc: bool = False,
) -> MDOFunctionGenerator:
"""Create a generator of :class:`.MDOFunction` from the names of the outputs.
Find a discipline which computes all the provided outputs
and build the associated MDOFunctionGenerator.
Args:
output_names: The names of the outputs.
top_level_disc: If True, search outputs among top level disciplines.
Returns:
A generator of :class:`.MDOFunction` instances.
"""
if top_level_disc:
search_among = self.get_top_level_disc()
else:
search_among = self.disciplines
for discipline in search_among:
if discipline.is_all_outputs_existing(output_names):
return MDOFunctionGenerator(discipline)
raise ValueError(
"No discipline known by formulation %s"
" has all outputs named %s" % (type(self).__name__, output_names)
)
def _get_generator_with_inputs(
self,
input_names: Iterable[str],
top_level_disc: bool = False,
) -> MDOFunctionGenerator:
"""Create a generator of :class:`.MDOFunction` from the names of the inputs.
Find a discipline which has all the provided inputs
and build the associated MDOFunctionGenerator.
Args:
input_names: The names of the inputs.
top_level_disc: If True, search inputs among the top level disciplines.
Returns:
A generator of :class:`.MDOFunction` instances.
"""
if top_level_disc:
search_among = self.get_top_level_disc()
else:
search_among = self.disciplines
for discipline in search_among:
if discipline.is_all_inputs_existing(input_names):
return MDOFunctionGenerator(discipline)
raise ValueError(
"No discipline known by formulation %s"
" has all inputs named %s" % (type(self).__name__, input_names)
)
def _get_dv_length(
self,
variable_name: str,
) -> int:
"""Retrieve the length of a variable.
This method relies on the size declared in the design space.
Args:
variable_name: The name of the variable.
Returns:
The size of the variable.
"""
return self.opt_problem.design_space.variables_sizes[variable_name]
def _get_dv_indices(
self,
names: Iterable[str],
) -> dict[str, tuple[int, int, int]]:
"""Return the indices associated with specific variables.
Args:
names: The names of the variables.
Returns:
For a each variable,
a 3-length tuple
whose first dimensions are its first and last indices in the design space
and last dimension is its size.
"""
start = end = 0
sizes = self.opt_problem.design_space.variables_sizes
names_to_indices = {}
for name in names:
size = sizes[name]
end += size
names_to_indices[name] = (start, end, size)
start = end
return names_to_indices
[docs] def unmask_x_swap_order(
self,
masking_data_names: Iterable[str],
x_masked: ndarray,
all_data_names: Iterable[str] | None = None,
x_full: ndarray = None,
) -> ndarray:
"""Unmask a vector from a subset of names, with respect to a set of names.
This method eventually swaps the order of the values
if the order of the data names is inconsistent between these sets.
Args:
masking_data_names: The names of the kept data.
x_masked: The boolean vector to unmask.
all_data_names: The set of all names.
If None, use the design variables stored in the design space.
x_full: The default values for the full vector.
If None, use the zero vector.
Returns:
The vector related to the input mask.
Raises:
IndexError: when the sizes of variables are inconsistent.
"""
if all_data_names is None:
all_data_names = self.get_optim_variables_names()
indices = self._get_dv_indices(all_data_names)
variables_sizes = self.opt_problem.design_space.variables_sizes
total_size = sum(variables_sizes[var] for var in all_data_names)
if x_full is None:
x_unmask = zeros(total_size, dtype=x_masked.dtype)
else:
x_unmask = copy(x_full)
i_x = 0
try:
for key in all_data_names:
if key in masking_data_names:
i_min, i_max, n_x = indices[key]
x_unmask[i_min:i_max] = x_masked[i_x : i_x + n_x]
i_x += n_x
except IndexError:
raise ValueError(
"Inconsistent input array size of values array "
"with reference data shape %s" % (x_unmask.shape)
)
return x_unmask
[docs] def mask_x_swap_order(
self,
masking_data_names: Iterable[str],
x_vect: ndarray,
all_data_names: Iterable[str] | None = None,
) -> ndarray:
"""Mask a vector from a subset of names, with respect to a set of names.
This method eventually swaps the order of the values
if the order of the data names is inconsistent between these sets.
Args:
masking_data_names: The names of the kept data.
x_vect: The vector to mask.
all_data_names: The set of all names.
If None, use the design variables stored in the design space.
Returns:
The masked version of the input vector.
Raises:
IndexError: when the sizes of variables are inconsistent.
"""
x_mask = self.get_x_mask_x_swap_order(masking_data_names, all_data_names)
return x_vect[x_mask]
[docs] def get_x_mask_x_swap_order(
self,
masking_data_names: Iterable[str],
all_data_names: Iterable[str] | None = None,
) -> ndarray:
"""Mask a vector from a subset of names, with respect to a set of names.
This method eventually swaps the order of the values
if the order of the data names is inconsistent between these sets.
Args:
masking_data_names: The names of the kept data.
x_vect: The vector to mask.
all_data_names: The set of all names.
If None, use the design variables stored in the design space.
Returns:
The masked version of the input vector.
Raises:
IndexError: when the sizes of variables are inconsistent.
ValueError: when the names of variables are inconsistent.
"""
design_space = self.opt_problem.design_space
if all_data_names is None:
all_data_names = design_space.variables_names
variables_sizes = design_space.variables_sizes
total_size = sum(variables_sizes[var] for var in masking_data_names)
indices = self._get_dv_indices(all_data_names)
x_mask = empty(total_size, dtype="int")
i_masked_min = i_masked_max = 0
try:
for key in masking_data_names:
i_min, i_max, loc_size = indices[key]
i_masked_max += loc_size
x_mask[i_masked_min:i_masked_max] = arange(i_min, i_max)
i_masked_min = i_masked_max
except KeyError as err:
raise ValueError(
"Inconsistent inputs of masking. "
"Key %s is in masking_data_names %s "
"but not in provided all_data_names : %s!"
% (err, masking_data_names, all_data_names)
)
return x_mask
def _remove_unused_variables(self) -> None:
"""Remove variables in the design space that are not discipline inputs."""
design_space = self.opt_problem.design_space
disciplines = self.get_top_level_disc()
all_inputs = {
var for disc in disciplines for var in disc.get_input_data_names()
}
for name in set(design_space.variables_names):
if name not in all_inputs:
design_space.remove_variable(name)
LOGGER.info(
"Variable %s was removed from the Design Space, it is not an input"
" of any discipline.",
name,
)
def _remove_sub_scenario_dv_from_ds(self) -> None:
"""Remove the sub scenarios design variables from the design space."""
for scenario in self.get_sub_scenarios():
loc_vars = scenario.design_space.variables_names
for var in loc_vars:
if var in self.design_space.variables_names:
self.design_space.remove_variable(var)
def _build_objective_from_disc(
self,
objective_name: str,
discipline: MDODiscipline | None = None,
top_level_disc: bool = True,
) -> None:
"""Build the objective function from the discipline able to compute it.
Args:
objective_name: The name of the objective function.
discipline: The discipline computing the objective function.
If None, the discipline is detected from the inner disciplines.
top_level_disc: If True, search the discipline among the top level ones.
"""
if isinstance(objective_name, str):
objective_name = [objective_name]
obj_mdo_fun = FunctionFromDiscipline(
objective_name, self, discipline, top_level_disc
)
obj_mdo_fun.f_type = MDOFunction.TYPE_OBJ
self.opt_problem.objective = obj_mdo_fun
if self._maximize_objective:
self.opt_problem.change_objective_sign()
[docs] def get_optim_variables_names(self) -> list[str]:
"""Get the optimization unknown names to be provided to the optimizer.
This is different from the design variable names provided by the user,
since it depends on the formulation,
and can include target values for coupling for instance in IDF.
Returns:
The optimization variable names.
"""
return self.opt_problem.design_space.variables_names
[docs] def get_x_names_of_disc(
self,
discipline: MDODiscipline,
) -> list[str]:
"""Get the design variables names of a given discipline.
Args:
discipline: The discipline.
Returns:
The names of the design variables.
"""
optim_variables_names = self.get_optim_variables_names()
input_names = discipline.get_input_data_names()
return [name for name in optim_variables_names if name in input_names]
[docs] def get_sub_disciplines(self) -> list[MDODiscipline]:
"""Accessor to the sub-disciplines.
This method lists the sub scenarios' disciplines.
Returns:
The sub-disciplines.
"""
sub_disciplines = []
def add_to_sub(disciplines: Iterable[MDODiscipline]) -> None:
"""Add the disciplines of the sub-scenarios if not already added it.
Args:
disciplines: The disciplines.
"""
for discipline in disciplines:
if discipline not in sub_disciplines:
sub_disciplines.append(discipline)
for discipline in self.disciplines:
if hasattr(discipline, "disciplines"):
add_to_sub(discipline.disciplines)
else:
add_to_sub([discipline])
return sub_disciplines
[docs] def get_sub_scenarios(self) -> list[Scenario]:
"""List the disciplines that are actually scenarios.
Returns:
The scenarios.
"""
return [disc for disc in self.disciplines if disc.is_scenario()]
def _set_default_input_values_from_design_space(self) -> None:
"""Initialize the top level disciplines from the design space."""
if not self.opt_problem.design_space.has_current_value():
return
current_x = self.opt_problem.design_space.get_current_value(as_dict=True)
for discipline in self.get_top_level_disc():
input_names = discipline.get_input_data_names()
discipline.default_inputs.update(
{
name: value
for name, value in current_x.items()
if name in input_names
}
)
[docs] def get_expected_workflow(
self,
) -> list[ExecutionSequence, tuple[ExecutionSequence]]:
"""Get the expected sequence of execution of the disciplines.
This method is used for the XDSM representation
and can be overloaded by subclasses.
For instance:
* [A, B] denotes the execution of A,
then the execution of B
* (A, B) denotes the concurrent execution of A and B
* [A, (B, C), D] denotes the execution of A,
then the concurrent execution of B and C,
then the execution of D.
Returns:
A sequence of elements which are either
an :class:`.ExecutionSequence`
or a tuple of :class:`.ExecutionSequence` for concurrent execution.
"""
raise NotImplementedError()
[docs] def get_expected_dataflow(
self,
) -> list[tuple[MDODiscipline, MDODiscipline, list[str]]]:
"""Get the expected data exchange sequence.
This method is used for the XDSM representation
and can be overloaded by subclasses.
Returns:
The expected sequence of data exchange
where the i-th item is described by the starting discipline,
the ending discipline and the coupling variables.
"""
raise NotImplementedError()
[docs] @classmethod
def get_default_sub_options_values(
cls, **options: str
) -> dict: # pylint: disable=W0613
"""Get the default values of the sub-options of the formulation.
When some options of the formulation depend on higher level options,
the default values of these sub-options may be obtained here,
mainly for use in the API.
Args:
**options: The options required to deduce the sub-options grammar.
Returns:
Either None or the sub-options default values.
"""
[docs] @classmethod
def get_sub_options_grammar(
cls, **options: str
) -> JSONGrammar: # pylint: disable=W0613
"""Get the sub-options grammar.
When some options of the formulation depend on higher level options,
the schema of the sub-options may be obtained here,
mainly for use in the API.
Args:
**options: The options required to deduce the sub-options grammar.
Returns:
Either None or the sub-options grammar.
"""
[docs]class BaseFormulationsFactory:
"""A factory of :class:`~gemseo.core.base_formulation.BaseFormulation`."""
def __init__(
self, cls: type[Any], module_names: Iterable[str] | None = None
) -> None:
self.factory = Factory(cls, module_names)
[docs] def create(
self,
formulation_name: str,
disciplines: Sequence[MDODiscipline],
objective_name: str,
design_space: DesignSpace,
**options,
) -> BaseFormulation:
"""Create a formulation.
Args:
formulation_name: The name of a class implementing a formulation.
disciplines: The disciplines.
objective_name: The name of the objective function.
design_space: The design space.
**options: The options for the creation of the formulation.
"""
return self.factory.create(
formulation_name,
disciplines=disciplines,
design_space=design_space,
objective_name=objective_name,
**options,
)
@property
def formulations(self) -> list[str]:
"""The available formulations."""
return self.factory.classes
[docs] def is_available(
self,
formulation_name: str,
) -> bool:
"""Check the availability of a formulation.
Args:
formulation_name: The formulation name to check.
Returns:
Whether the formulation is available.
"""
return self.factory.is_available(formulation_name)