#738 check model option

CHANGELOG.md

@@ -21,6 +21,7 @@
 
 ## Optimizations
 
+-   Added an option to skip model checks during discretisation, which could be slow for large models ([#739](https://github.com/pybamm-team/PyBaMM/pull/739))
 -   Use CasADi's automatic differentation algorithms by default when solving a model ([#714](https://github.com/pybamm-team/PyBaMM/pull/714))
 -   Avoid re-checking size when making a copy of an `Index` object ([#656](https://github.com/pybamm-team/PyBaMM/pull/656))
 -   Avoid recalculating `_evaluation_array` when making a copy of a `StateVector` object ([#653](https://github.com/pybamm-team/PyBaMM/pull/653))

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

@@ -33,4 +33,4 @@ Negative current collector thermal conductivity [W.m-1.K-1],401,,
 Positive current collector thermal conductivity [W.m-1.K-1],237,,
 ,,,
 # Electrical,,,
-Cell capacity [A.h],0.68,,24 Ah/m2 * 0.137m * 0.207m
+Cell capacity [A.h],0.680616,,24 Ah/m2 * 0.137m * 0.207m

pybamm/discretisations/discretisation.py

@@ -82,7 +82,7 @@ def bcs(self, value):
         # reset discretised_symbols
         self._discretised_symbols = {}
 
-    def process_model(self, model, inplace=True):
+    def process_model(self, model, inplace=True, check_model=True):
         """Discretise a model.
         Currently inplace, could be changed to return a new model.
 
@@ -91,9 +91,15 @@ def process_model(self, model, inplace=True):
         model : :class:`pybamm.BaseModel`
             Model to dicretise. Must have attributes rhs, initial_conditions and
             boundary_conditions (all dicts of {variable: equation})
-        inplace: bool, optional
+        inplace : bool, optional
             If True, discretise the model in place. Otherwise, return a new
             discretised model. Default is True.
+        check_model : bool, optional
+            If True, model checks are performed after discretisation. For large
+            systems these checks can be slow, so can be skipped by setting this
+            option to False. When developing, testing or debugging it is recommened
+            to leave this option as True as it may help to identify any errors.
+            Default is True.
 
         Returns
         -------
@@ -173,7 +179,9 @@ def process_model(self, model, inplace=True):
         model_disc.mass_matrix = self.create_mass_matrix(model_disc)
 
         # Check that resulting model makes sense
-        self.check_model(model_disc)
+        if check_model:
+            pybamm.logger.info("Performing model checks for {}".format(model.name))
+            self.check_model(model_disc)
 
         pybamm.logger.info("Finish discretising {}".format(model.name))
 

pybamm/simulation.py

@@ -98,13 +98,19 @@ def set_parameters(self):
         )
         self._parameter_values.process_geometry(self._geometry)
 
-    def build(self):
+    def build(self, check_model=True):
         """
         A method to build the model into a system of matrices and vectors suitable for
         performing numerical computations. If the model has already been built or
         solved then this function will have no effect. If you want to rebuild,
         first use "reset()". This method will automatically set the parameters
         if they have not already been set.
+
+        Parameters
+        ----------
+        check_model : bool, optional
+            If True, model checks are performed after discretisation (see
+            :meth:`pybamm.Discretisation.process_model`). Default is True.
         """
 
         if self.built_model:
@@ -113,9 +119,11 @@ def build(self):
         self.set_parameters()
         self._mesh = pybamm.Mesh(self._geometry, self._submesh_types, self._var_pts)
         self._disc = pybamm.Discretisation(self._mesh, self._spatial_methods)
-        self._built_model = self._disc.process_model(self._model, inplace=False)
+        self._built_model = self._disc.process_model(
+            self._model, inplace=False, check_model=check_model
+        )
 
-    def solve(self, t_eval=None, solver=None):
+    def solve(self, t_eval=None, solver=None, check_model=True):
         """
         A method to solve the model. This method will automatically build
         and set the model parameters if not already done so.
@@ -129,8 +137,11 @@ def solve(self, t_eval=None, solver=None):
             non-dimensional time of 1.
         solver : :class:`pybamm.BaseSolver`
             The solver to use to solve the model.
+        check_model : bool, optional
+            If True, model checks are performed after discretisation (see
+            :meth:`pybamm.Discretisation.process_model`). Default is True.
         """
-        self.build()
+        self.build(check_model=check_model)
 
         if t_eval is None:
             try:

tests/unit/test_discretisations/test_discretisation.py

@@ -852,6 +852,23 @@ def test_check_tab_bcs_error(self):
         with self.assertRaisesRegex(pybamm.ModelError, "Boundary conditions"):
             disc.check_tab_conditions(b, bcs)
 
+    def test_process_with_no_check(self):
+        # create model
+        whole_cell = ["negative electrode", "separator", "positive electrode"]
+        c = pybamm.Variable("c", domain=whole_cell)
+        N = pybamm.grad(c)
+        model = pybamm.BaseModel()
+        model.rhs = {c: pybamm.div(N)}
+        model.initial_conditions = {c: pybamm.Scalar(3)}
+        model.boundary_conditions = {
+            c: {"left": (0, "Neumann"), "right": (0, "Neumann")}
+        }
+        model.variables = {"c": c, "N": N}
+
+        # create discretisation
+        disc = get_discretisation_for_testing()
+        disc.process_model(model, check_model=False)
+
 
 if __name__ == "__main__":
     print("Add -v for more debug output")

tests/unit/test_parameters/test_update_parameters.py

@@ -47,7 +47,7 @@ def test_update_model(self):
         model2 = pybamm.lithium_ion.SPM()
         modeltest2 = tests.StandardModelTest(model2)
         modeltest2.test_all(skip_output_tests=True)
-        self.assertEqual(model2.variables["Current [A]"].evaluate(), 0.68)
+        self.assertEqual(model2.variables["Current [A]"].evaluate(), 0.680616)
         # process and solve with updated parameter values
         parameter_values_update = pybamm.ParameterValues(
             chemistry=pybamm.parameter_sets.Marquis2019
@@ -73,8 +73,6 @@ def test_update_model(self):
         modeltest3.test_solving(t_eval=t_eval)
         Y3 = modeltest3.solution.y
 
-        # function.parameters should be pybamm.Scalar(0), but parameters_eval s
-        # should be a float
         self.assertIsInstance(model3.variables["Current [A]"], pybamm.Scalar)
         self.assertEqual(model3.variables["Current [A]"].evaluate(), 0.0)
 

tests/unit/test_simulation.py

@@ -71,6 +71,13 @@ def test_solve(self):
 
         self.assertEqual(sim._solution, None)
 
+        # test solve without check
+        sim.reset()
+        sim.solve(check_model=False)
+        for val in list(sim.built_model.rhs.values()):
+            self.assertFalse(val.has_symbol_of_classes(pybamm.Parameter))
+            self.assertTrue(val.has_symbol_of_classes(pybamm.Matrix))
+
     def test_reuse_commands(self):
 
         sim = pybamm.Simulation(pybamm.lithium_ion.SPM())