#846 changelog

CHANGELOG.md

@@ -1,12 +1,10 @@
 # [Unreleased](https://github.com/pybamm-team/PyBaMM)
-## Features 
-
-- Add ambient temperature as a function of time ([#872](https://github.com/pybamm-team/PyBaMM/pull/872))
 
-## Features
+## Features 
 
--   Added `Minimum`, `Maximum` and `Sign` operators
+-   Added `Minimum`, `Maximum` and `Sign` operators ([#876](https://github.com/pybamm-team/PyBaMM/pull/876))
 -   Added `CasadiAlgebraicSolver` for solving algebraic systems with CasADi ([#868](https://github.com/pybamm-team/PyBaMM/pull/868))
+-   Add ambient temperature as a function of time ([#872](https://github.com/pybamm-team/PyBaMM/pull/872))
 
 ## Bug fixes
 

examples/scripts/DFN_ambient_temperature.py

@@ -1,5 +1,5 @@
 #
-# Example showing how to load and solve the DFN
+# Example showing how to solve the DFN with a varying ambient temperature
 #
 
 import pybamm

pybamm/solvers/base_solver.py

@@ -527,8 +527,11 @@ def solve(self, model, t_eval=None, external_variables=None, inputs=None):
 
         # t_eval can only be None if the solver is an algebraic solver. In that case
         # set it to 0
-        if self.algebraic_solver is True and t_eval is None:
-            t_eval = np.array([0])
+        if t_eval is None:
+            if self.algebraic_solver is True:
+                t_eval = np.array([0])
+            else:
+                raise ValueError("t_eval cannot be None")
 
         # Make sure t_eval is monotonic
         if (np.diff(t_eval) < 0).any():

pybamm/solvers/casadi_algebraic_solver.py

@@ -19,11 +19,12 @@ class CasadiAlgebraicSolver(pybamm.BaseSolver):
         The tolerance for the solver (default is 1e-6).
     """
 
-    def __init__(self, method="lm", tol=1e-6):
+    def __init__(self, method="lm", tol=1e-6, **extra_options):
         super().__init__()
         self.tol = tol
         self.name = "CasADi algebraic solver"
         self.algebraic_solver = True
+        self.extra_options = extra_options
         pybamm.citations.register("Andersson2019")
 
     @property
@@ -62,7 +63,10 @@ def _integrate(self, model, t_eval, inputs=None):
 
         # Set up rootfinder
         roots = casadi.rootfinder(
-            "roots", "newton", dict(x=y_sym, p=t_u_sym, g=alg), {"abstol": self.tol}
+            "roots",
+            "newton",
+            dict(x=y_sym, p=t_u_sym, g=alg),
+            {**self.extra_options, "abstol": self.tol},
         )
         for idx, t in enumerate(t_eval):
             # Evaluate algebraic with new t and previous y0, if it's already close

tests/unit/test_solvers/test_base_solver.py

@@ -28,6 +28,18 @@ def test_step_or_solve_empty_model(self):
         with self.assertRaisesRegex(pybamm.ModelError, "Cannot solve empty model"):
             solver.solve(model, None)
 
+    def test_t_eval_none(self):
+        model = pybamm.BaseModel()
+        v = pybamm.Variable("v")
+        model.rhs = {v: 1}
+        model.initial_conditions = {v: 1}
+        disc = pybamm.Discretisation()
+        disc.process_model(model)
+
+        solver = pybamm.BaseSolver()
+        with self.assertRaisesRegex(ValueError, "t_eval cannot be None"):
+            solver.solve(model, None)
+
     def test_nonmonotonic_teval(self):
         solver = pybamm.BaseSolver(rtol=1e-2, atol=1e-4)
         model = pybamm.BaseModel()

tests/unit/test_solvers/test_casadi_algebraic_solver.py

@@ -50,6 +50,11 @@ def algebraic_eval(self, t, y):
             pybamm.SolverError, "Could not find acceptable solution: .../casadi",
         ):
             solver._integrate(model, np.array([0]), {})
+        solver = pybamm.CasadiAlgebraicSolver(error_on_fail=False)
+        with self.assertRaisesRegex(
+            pybamm.SolverError, "Could not find acceptable solution: solver terminated",
+        ):
+            solver._integrate(model, np.array([0]), {})
 
     def test_model_solver_with_time(self):
         # Create model