# Source code for pybamm.models.submodels.base_submodel

```
#
# Base submodel class
#
import pybamm
[docs]
class BaseSubModel(pybamm.BaseModel):
"""
The base class for all submodels. All submodels inherit from this class and must
only provide public methods which overwrite those in this base class. Any methods
added to a submodel that do not overwrite those in this bass class are made
private with the prefix '_', providing a consistent public interface for all
submodels.
Parameters
----------
param: parameter class
The model parameter symbols
domain : str
The domain of the model either 'Negative' or 'Positive'
name: str
A string giving the name of the submodel
external: bool, optional
Whether the variables defined by the submodel will be provided externally
by the users. Default is 'False'.
options: dict
A dictionary of options to be passed to the model.
See :class:`pybamm.BaseBatteryModel`
phase : str, optional
Phase of the particle (default is None).
Attributes
----------
param: parameter class
The model parameter symbols
rhs: dict
A dictionary that maps expressions (variables) to expressions that represent
the rhs
algebraic: dict
A dictionary that maps expressions (variables) to expressions that represent
the algebraic equations. The algebraic expressions are assumed to equate
to zero. Note that all the variables in the model must exist in the keys of
`rhs` or `algebraic`.
initial_conditions: dict
A dictionary that maps expressions (variables) to expressions that represent
the initial conditions for the state variables y. The initial conditions for
algebraic variables are provided as initial guesses to a root finding algorithm
that calculates consistent initial conditions.
boundary_conditions: dict
A dictionary that maps expressions (variables) to expressions that represent
the boundary conditions
variables: dict
A dictionary that maps strings to expressions that represent
the useful variables
events: list
A list of events. Each event can either cause the solver to terminate
(e.g. concentration goes negative), or be used to inform the solver of the
existance of a discontinuity (e.g. discontinuity in the input current)
"""
def __init__(
self,
param,
domain=None,
name="Unnamed submodel",
external=False,
options=None,
phase=None,
):
super().__init__(name)
self.domain = domain
self.name = name
self.external = external
if options is None or type(options) == dict: # noqa: E721
options = pybamm.BatteryModelOptions(options)
self.options = options
self.param = param
if param is None or domain is None:
self.domain_param = None
else:
self.domain_param = param.domain_params[self.domain]
if phase is not None:
self.phase_param = self.domain_param.phase_params[phase]
# Error checks for phase and domain
self.set_phase(phase)
def set_phase(self, phase):
if phase is not None:
if self.domain is None:
raise ValueError("Phase must be None if domain is None")
options_phase = getattr(self.options, self.domain)["particle phases"]
if options_phase == "1" and phase != "primary":
raise ValueError("Phase must be 'primary' if there is only one phase")
elif options_phase == "2" and phase not in ["primary", "secondary"]:
raise ValueError(
"Phase must be either 'primary' or 'secondary' "
"if there are two phases"
)
if options_phase == "1" and phase == "primary":
# Only one phase, no need to distinguish between
# "primary" and "secondary"
self.phase_name = ""
else:
# add a space so that we can use "" or (e.g.) "primary " interchangeably
# when naming variables
self.phase_name = phase + " "
self.phase = phase
@property
def domain(self):
return self._domain
@domain.setter
def domain(self, domain):
if domain is not None:
domain = domain.lower()
ok_domain_list = ["negative", "separator", "positive", None]
if domain in ok_domain_list:
self._domain = domain
if domain is not None:
self._Domain = domain.capitalize()
else:
raise pybamm.DomainError(
f"Domain '{domain}' not recognised (must be one of {ok_domain_list})"
)
@property
def domain_Domain(self):
return self._domain, self._Domain
[docs]
def get_fundamental_variables(self):
"""
A public method that creates and returns the variables in a submodel which can
be created independent of other submodels. For example, the electrolyte
concentration variables can be created independent of whether any other
variables have been defined in the model. As a rule, if a variable can be
created without variables from other submodels, then it should be placed in
this method.
Returns
-------
dict :
The variables created by the submodel which are independent of variables in
other submodels.
"""
return {}
[docs]
def get_coupled_variables(self, variables):
"""
A public method that creates and returns the variables in a submodel which
require variables in other submodels to be set first. For example, the
exchange current density requires the concentration in the electrolyte to
be created before it can be created. If a variable can be created independent
of other submodels then it should be created in 'get_fundamental_variables'
instead of this method.
Parameters
----------
variables: dict
The variables in the whole model.
Returns
-------
dict :
The variables created in this submodel which depend on variables in
other submodels.
"""
return {}
[docs]
def set_rhs(self, variables):
"""
A method to set the right hand side of the differential equations which contain
a time derivative. Note: this method modifies the state of self.rhs. Unless
overwritten by a submodel, the default behaviour of 'pass' is used as
implemented in :class:`pybamm.BaseSubModel`.
Parameters
----------
variables: dict
The variables in the whole model.
"""
pass
[docs]
def set_algebraic(self, variables):
"""
A method to set the differential equations which do not contain a time
derivative. Note: this method modifies the state of self.algebraic. Unless
overwritten by a submodel, the default behaviour of 'pass' is used as
implemented in :class:`pybamm.BaseSubModel`.
Parameters
----------
variables: dict
The variables in the whole model.
"""
pass
[docs]
def set_boundary_conditions(self, variables):
"""
A method to set the boundary conditions for the submodel. Note: this method
modifies the state of self.boundary_conditions. Unless overwritten by a
submodel, the default behaviour of 'pass' is used as implemented in
:class:`pybamm.BaseSubModel`.
Parameters
----------
variables: dict
The variables in the whole model.
"""
pass
[docs]
def set_initial_conditions(self, variables):
"""
A method to set the initial conditions for the submodel. Note: this method
modifies the state of self.initial_conditions. Unless overwritten by a
submodel, the default behaviour of 'pass' is used as implemented in
:class:`pybamm.BaseSubModel`.
Parameters
----------
variables: dict
The variables in the whole model.
"""
pass
[docs]
def set_events(self, variables):
"""
A method to set events related to the state of submodel variable. Note: this
method modifies the state of self.events. Unless overwritten by a submodel, the
default behaviour of 'pass' is used as implemented in
:class:`pybamm.BaseSubModel`.
Parameters
----------
variables: dict
The variables in the whole model.
"""
pass
```