Source code for pybamm.models.event
from __future__ import annotations
from enum import Enum
import numpy as np
from typing import TypeVar
[docs]
class EventType(Enum):
"""
Defines the type of event, see :class:`pybamm.Event`
TERMINATION indicates an event that will terminate the solver, the expression should
return 0 when the event is triggered
DISCONTINUITY indicates an expected discontinuity in the solution, the expression
should return the time that the discontinuity occurs. The solver will integrate up
to the discontinuity and then restart just after the discontinuity.
INTERPOLANT_EXTRAPOLATION indicates that a pybamm.Interpolant object has been
evaluated outside of the range.
SWITCH indicates an event switch that is used in CasADI "fast with events" model.
"""
TERMINATION = 0
DISCONTINUITY = 1
INTERPOLANT_EXTRAPOLATION = 2
SWITCH = 3
E = TypeVar("E", bound="Event")
[docs]
class Event:
"""
Defines an event for use within a pybamm model
Attributes
----------
name: str
A string giving the name of the event.
expression: :class:`pybamm.Symbol`
An expression that defines when the event occurs.
event_type: :class:`pybamm.EventType` (optional)
An enum defining the type of event. By default it is set to TERMINATION.
"""
def __init__(self, name, expression, event_type=EventType.TERMINATION):
self._name = name
self._expression = expression
self._event_type = event_type
@classmethod
def _from_json(cls: type[E], snippet: dict) -> E:
"""
Reconstructs an Event instance during deserialisation of a JSON file.
Parameters
----------
snippet: dict
Contains the information needed to reconstruct a specific instance.
Should contain "name", "expression" and "event_type".
"""
return cls(
snippet["name"],
snippet["expression"],
event_type=EventType(snippet["event_type"][1]),
)
[docs]
def evaluate(
self,
t: float | None = None,
y: np.ndarray | None = None,
y_dot: np.ndarray | None = None,
inputs: dict | None = None,
):
"""
Acts as a drop-in replacement for :func:`pybamm.Symbol.evaluate`
"""
return self._expression.evaluate(t, y, y_dot, inputs)
def __str__(self):
return self._name
@property
def name(self):
return self._name
@property
def expression(self):
return self._expression
@property
def event_type(self):
return self._event_type
[docs]
def to_json(self):
"""
Method to serialise an Event object into JSON.
The expression is written out seperately,
See :meth:`pybamm.Serialise._SymbolEncoder.default()`
"""
# event_type contains string name, for JSON readability,
# and value for deserialisation.
json_dict = {
"name": self._name,
"event_type": [str(self._event_type), self._event_type.value],
}
return json_dict