#939 remove C-rate, make copies of sim attributes

CHANGELOG.md

@@ -13,13 +13,15 @@
 
 ## Bug fixes
 
+-   Added default values to base model so that it works with the `Simulation` class
 -   Reformatted thermal submodels ([#938](https://github.com/pybamm-team/PyBaMM/pull/938)
 -   Reformatted electrolyte submodels ([#927](https://github.com/pybamm-team/PyBaMM/pull/927))
 
 ## Breaking changes
 
 -   Removed some inputs like `T_inf`, `R_g` and activation energies to some of the standard function parameters. This is because each of those inputs is specific to a particular function (e.g. the reference temperature at which the function was measured). To change a property such as the activation energy, users should create a new function, specifying the relevant property as a `Parameter` or `InputParameter` ([#942](https://github.com/pybamm-team/PyBaMM/pull/942))
 -   The thermal option 'xyz-lumped' has been removed. The option 'thermal current collector' has also been removed ([#938](https://github.com/pybamm-team/PyBaMM/pull/938)
+-   The 'C-rate' parameter has been deprecated. Use 'Current function [A]' instead. The cell capacity can be accessed as 'Cell capacity [A.h]', and used to calculate current from C-rate 
 
 # [v0.2.1](https://github.com/pybamm-team/PyBaMM/tree/v0.2.1) - 2020-03-31
 

pybamm/input/parameters/lead-acid/cells/BBOXX_Sulzer2019/parameters.csv

@@ -19,7 +19,7 @@ Positive tab centre z-coordinate [m],0.114,Tab at top,
 # Electrical,,,
 Cell capacity [A.h],17,Manufacturer,
 Typical current [A],1,,
-
+Current function [A],1,default current function,
 ,,,
 # Density,,,
 Negative current collector density [kg.m-3],11300, same as electrode,

pybamm/input/parameters/lead-acid/experiments/1C_discharge_from_full/parameters.csv

@@ -14,7 +14,6 @@ Number of electrodes connected in parallel to make a cell,8,Manufacturer,
 Number of cells connected in series to make a battery,6,Manufacturer,
 Lower voltage cut-off [V],1.73,(just under) 10.5V across 6-cell battery,
 Upper voltage cut-off [V],2.44,(just over) 14.5V across 6-cell battery,
-C-rate,0.1,,
 ,,,
 # Initial conditions
 Initial State of Charge,1,-,

pybamm/input/parameters/lithium-ion/cells/Kim2011/parameters.csv

@@ -35,3 +35,4 @@ Positive current collector thermal conductivity [W.m-1.K-1],158.079, 237 * 0.667
 # Electrical,,,
 Cell capacity [A.h],0.43,trial and error,
 Typical current [A],0.43,0.2857,1C current
+Current function [A],0.43,default current function,

pybamm/input/parameters/lithium-ion/cells/LGM50_Chen2020/parameters.csv

@@ -34,4 +34,5 @@ Positive current collector thermal conductivity [W.m-1.K-1],237,CRC Handbook,alu
 ,,,
 # Electrical,,,
 Cell capacity [A.h],5,Chen 2020,
-Typical current [A],5,Chen 2020,
+Typical current [A],5,Chen 2020,
+Current function [A],5,default current function,

pybamm/input/parameters/lithium-ion/cells/UMBL_Mohtat2020/parameters.csv

@@ -35,3 +35,4 @@ Positive current collector thermal conductivity [W.m-1.K-1],237,,
 # Electrical,,,
 Cell capacity [A.h],5,Peyman MPM,
 Typical current [A],5,,1C current
+Current function [A],5,default current function,

pybamm/input/parameters/lithium-ion/cells/kokam_Ecker2015/parameters.csv

@@ -13,3 +13,4 @@ Electrode width [m],8.50E-02,,
 # Electrical,,,
 Cell capacity [A.h], 0.15625, 7.5/48 (parameter set for a single layer cell),
 Typical current [A], 0.15652,,
+Current function [A],0.15652,default current function,

pybamm/input/parameters/lithium-ion/cells/kokam_Marquis2019/parameters.csv

@@ -35,3 +35,4 @@ Positive current collector thermal conductivity [W.m-1.K-1],237,,
 # Electrical,,,
 Cell capacity [A.h],0.680616,,24 Ah/m2 * 0.137m * 0.207m
 Typical current [A],0.680616,,1C current
+Current function [A],0.680616,default current function,

pybamm/input/parameters/lithium-ion/experiments/1C_charge_from_empty_Mohtat2020/parameters.csv

@@ -11,7 +11,6 @@ Number of electrodes connected in parallel to make a cell,1,,
 Number of cells connected in series to make a battery,1,,
 Lower voltage cut-off [V],2.5,,
 Upper voltage cut-off [V],4.2,,
-C-rate,-1,,
 ,,,
 # Initial conditions
 Initial concentration in negative electrode [mol.m-3],48.8682,Peyman MPM, x0 (0.0017) * Csmax_n

pybamm/input/parameters/lithium-ion/experiments/1C_discharge_from_full_Chen2020/parameters.csv

@@ -12,7 +12,6 @@ Number of electrodes connected in parallel to make a cell,1,,
 Number of cells connected in series to make a battery,1,,
 Lower voltage cut-off [V],2.5,,
 Upper voltage cut-off [V],4.4,,
-C-rate,1,,
 ,,,
 # Initial conditions
 Initial concentration in negative electrode [mol.m-3],30086,Chen 2020,

pybamm/input/parameters/lithium-ion/experiments/1C_discharge_from_full_Ecker2015/parameters.csv

@@ -12,7 +12,6 @@ Number of electrodes connected in parallel to make a cell,1,,
 Number of cells connected in series to make a battery,1,,
 Lower voltage cut-off [V],2.5,,
 Upper voltage cut-off [V],4.2,,
-C-rate,1,,
 ,,,
 # Initial conditions
 Initial concentration in negative electrode [mol.m-3], 26120.05,,

pybamm/input/parameters/lithium-ion/experiments/1C_discharge_from_full_Kim2011/parameters.csv

@@ -12,7 +12,6 @@ Number of electrodes connected in parallel to make a cell,1,,
 Number of cells connected in series to make a battery,1,,
 Lower voltage cut-off [V],2.7,,
 Upper voltage cut-off [V],4.5,,
-C-rate,1,,
 ,,,
 # Initial conditions
 Initial concentration in negative electrode [mol.m-3],18081,0.63*2.84E4,

pybamm/input/parameters/lithium-ion/experiments/1C_discharge_from_full_Marquis2019/parameters.csv

@@ -11,7 +11,6 @@ Number of electrodes connected in parallel to make a cell,1,,
 Number of cells connected in series to make a battery,1,,
 Lower voltage cut-off [V],3.105,,
 Upper voltage cut-off [V],4.7,,
-C-rate,1,,
 ,,,
 # Initial conditions
 Initial concentration in negative electrode [mol.m-3],19986.609595075,Scott Moura FastDFN,

pybamm/parameters/parameter_values.py

@@ -5,7 +5,6 @@
 import pandas as pd
 import os
 import numbers
-import numpy as np
 from pprint import pformat
 
 
@@ -115,6 +114,11 @@ def items(self):
         "Get the items of the dictionary"
         return self._dict_items.items()
 
+    def copy(self):
+        """Returns a copy of the parameter values. Makes sure to copy the internal
+        dictionary."""
+        return ParameterValues(values=self._dict_items.copy())
+
     def search(self, key, print_values=True):
         """
         Search dictionary for keys containing 'key'.
@@ -284,52 +288,12 @@ def check_and_update_parameter_values(self, values):
                 "'Typical current [A]' cannot be zero. A possible alternative is to "
                 "set 'Current function [A]' to `0` instead."
             )
-        if "C-rate" in values and "Current function [A]" in values:
+        if "C-rate" in values:
             raise ValueError(
-                "Cannot provide both 'C-rate' and 'Current function [A]' simultaneously"
+                "The 'C-rate' parameter has been deprecated, "
+                "use 'Current function [A]' instead. The cell capacity can be accessed "
+                "as 'Cell capacity [A.h]', and used to calculate current from C-rate."
             )
-        # If the capacity of the cell has been provided, make sure "C-rate" and current
-        # match with the stated capacity
-        if "Cell capacity [A.h]" in values or "Cell capacity [A.h]" in self._dict_items:
-            # Capacity from values takes precedence
-            if "Cell capacity [A.h]" in values:
-                capacity = values["Cell capacity [A.h]"]
-            else:
-                capacity = self._dict_items["Cell capacity [A.h]"]
-            # Make sure they match if both provided
-            # Update the other if only one provided
-            if "C-rate" in values:
-                # Can't provide C-rate as a function
-                if callable(values["C-rate"]):
-                    value = CrateToCurrent(values["C-rate"], capacity)
-                elif isinstance(values["C-rate"], tuple):
-                    data = values["C-rate"][1]
-                    current_data = np.stack([data[:, 0], data[:, 1] * capacity], axis=1)
-                    value = (values["C-rate"][0] + "_to_current", current_data)
-                elif values["C-rate"] == "[input]":
-                    value = CrateToCurrent(values["C-rate"], capacity, typ="input")
-                else:
-                    value = values["C-rate"] * capacity
-                self._dict_items["Current function [A]"] = value
-            elif "Current function [A]" in values:
-                if callable(values["Current function [A]"]):
-                    value = CurrentToCrate(values["Current function [A]"], capacity)
-                elif isinstance(values["Current function [A]"], tuple):
-                    data = values["Current function [A]"][1]
-                    c_rate_data = np.stack([data[:, 0], data[:, 1] / capacity], axis=1)
-                    value = (
-                        values["Current function [A]"][0] + "_to_Crate",
-                        c_rate_data,
-                    )
-                elif values["Current function [A]"] == "[input]":
-                    value = CurrentToCrate(
-                        values["Current function [A]"], capacity, typ="input"
-                    )
-                else:
-                    value = values["Current function [A]"] / capacity
-                self._dict_items["C-rate"] = value
-
-        return values
 
     def process_model(self, unprocessed_model, inplace=True):
         """Assign parameter values to a model.
@@ -605,33 +569,3 @@ def evaluate(self, symbol):
 
     def _ipython_key_completions_(self):
         return list(self._dict_items.keys())
-
-
-class CurrentToCrate:
-    "Convert a current function to a C-rate function"
-
-    def __init__(self, current, capacity, typ="function"):
-        self.current = current
-        self.capacity = capacity
-        self.type = typ
-
-    def __call__(self, t):
-        if self.type == "function":
-            return self.current(t) / self.capacity
-        elif self.type == "input":
-            return pybamm.InputParameter("Current function [A]") / self.capacity
-
-
-class CrateToCurrent:
-    "Convert a C-rate function to a current function"
-
-    def __init__(self, Crate, capacity, typ="function"):
-        self.Crate = Crate
-        self.capacity = capacity
-        self.type = typ
-
-    def __call__(self, t):
-        if self.type == "function":
-            return self.Crate(t) * self.capacity
-        elif self.type == "input":
-            return pybamm.InputParameter("C-rate") * self.capacity

pybamm/parameters/print_parameters.py

@@ -61,7 +61,11 @@ def print_parameters(parameters, parameter_values, output_file=None):
     # Calculate parameters for each C-rate
     for Crate in [1, 10]:
         # Update Crate
-        parameter_values.update({"C-rate": Crate}, check_already_exists=False)
+        capacity = parameter_values.get("Cell capacity [A.h]")
+        if capacity is not None:
+            parameter_values.update(
+                {"Current function [A]": Crate * capacity}, check_already_exists=False
+            )
         for name, symbol in parameters.items():
             if not callable(symbol):
                 proc_symbol = parameter_values.process_symbol(symbol)

pybamm/simulation.py

@@ -88,9 +88,14 @@ def __init__(
 
         if experiment is None:
             self.operating_mode = "without experiment"
-            self.C_rate = C_rate
-            if self.C_rate:
-                self._parameter_values.update({"C-rate": self.C_rate})
+            if C_rate:
+                self.C_rate = C_rate
+                self._parameter_values.update(
+                    {
+                        "Current function [A]": self.C_rate
+                        * self._parameter_values["Cell capacity [A.h]"]
+                    }
+                )
             self.model = model
         else:
             self.set_up_experiment(model, experiment)
@@ -344,8 +349,8 @@ def solve(
             # input. If the current is provided as data then the "Current function [A]"
             # is the tuple (filename, data).
             # First, read the current function (if provided, otherwise return None)
-            current_function = self._parameter_values.get("Current function [A]")
-            if isinstance(current_function, tuple):
+            current = self._parameter_values.get("Current function [A]")
+            if isinstance(current, tuple):
                 filename = self._parameter_values["Current function [A]"][0]
                 time_data = self._parameter_values["Current function [A]"][1][:, 0]
                 # If no t_eval is provided, we use the times provided in the data.
@@ -392,14 +397,15 @@ def solve(
             # If not using a drive cycle and t_eval is not provided, set t_eval
             # to correspond to a single discharge
             elif t_eval is None:
-                # Get C-rate, return None if it doesn't exist
-                C_rate = self._parameter_values.get("C-rate")
-                if C_rate is None:
+                if current is None:
                     t_end = 1
                 else:
-                    if isinstance(C_rate, pybamm.InputParameter):
-                        C_rate = inputs["C-rate"]
+                    # Get C-rate, return None if it doesn't exist
+                    capacity = self.parameter_values["Cell capacity [A.h]"]
+                    if isinstance(current, pybamm.InputParameter):
+                        C_rate = inputs["Current function [A]"] / capacity
                     try:
+                        C_rate = current / capacity
                         t_end = 3600 / C_rate
                     except TypeError:
                         t_end = 3600
@@ -575,7 +581,7 @@ def geometry(self):
 
     @geometry.setter
     def geometry(self, geometry):
-        self._geometry = copy.copy(geometry)
+        self._geometry = geometry.copy()
         self._unprocessed_geometry = copy.deepcopy(geometry)
 
     @property
@@ -588,15 +594,15 @@ def parameter_values(self):
 
     @parameter_values.setter
     def parameter_values(self, parameter_values):
-        self._parameter_values = copy.copy(parameter_values)
+        self._parameter_values = parameter_values.copy()
 
     @property
     def submesh_types(self):
         return self._submesh_types
 
     @submesh_types.setter
     def submesh_types(self, submesh_types):
-        self._submesh_types = copy.copy(submesh_types)
+        self._submesh_types = submesh_types.copy()
 
     @property
     def mesh(self):
@@ -608,23 +614,23 @@ def var_pts(self):
 
     @var_pts.setter
     def var_pts(self, var_pts):
-        self._var_pts = copy.copy(var_pts)
+        self._var_pts = var_pts.copy()
 
     @property
     def spatial_methods(self):
         return self._spatial_methods
 
     @spatial_methods.setter
     def spatial_methods(self, spatial_methods):
-        self._spatial_methods = copy.copy(spatial_methods)
+        self._spatial_methods = spatial_methods.copy()
 
     @property
     def solver(self):
         return self._solver
 
     @solver.setter
     def solver(self, solver):
-        self._solver = copy.copy(solver)
+        self._solver = solver.copy()
 
     @property
     def quick_plot_vars(self):
@@ -681,7 +687,7 @@ def specs(
         """
 
         if model_options:
-            self._model_options = copy.copy(model_options)
+            self._model_options = model_options.copy()
 
         if geometry:
             self.geometry = geometry
@@ -701,7 +707,12 @@ def specs(
 
         if C_rate:
             self.C_rate = C_rate
-            self.parameter_values.update({"C-rate": self.C_rate})
+            self._parameter_values.update(
+                {
+                    "Current function [A]": self.C_rate
+                    * self._parameter_values["Cell capacity [A.h]"]
+                }
+            )
 
         if (
             model_options

pybamm/solvers/base_solver.py

@@ -2,6 +2,7 @@
 # Base solver class
 #
 import casadi
+import copy
 import pybamm
 import numbers
 import numpy as np
@@ -105,6 +106,13 @@ def max_steps(self):
     def max_steps(self, max_steps):
         self._max_steps = max_steps
 
+    def copy(self):
+        "Returns a copy of the solver"
+        new_solver = copy.copy(self)
+        # clear models_set_up
+        new_solver.models_set_up = set()
+        return new_solver
+
     def set_up(self, model, inputs=None):
         """Unpack model, perform checks, simplify and calculate jacobian.
 

tests/integration/test_models/standard_model_tests.py

@@ -70,7 +70,10 @@ def test_solving(self, solver=None, t_eval=None):
         self.solver.rtol = 1e-8
         self.solver.atol = 1e-8
 
-        Crate = abs(self.parameter_values["C-rate"])
+        Crate = abs(
+            self.parameter_values["Current function [A]"]
+            * self.parameter_values["Cell capacity [A.h]"]
+        )
         # don't allow zero C-rate
         if Crate == 0:
             Crate = 1