Allow lists of input parameters as initial conditions

src/pybamm/models/base_model.py

@@ -468,6 +468,17 @@ def algebraic_root_solver(self):
     def algebraic_root_solver(self, algebraic_root_solver):
         self._algebraic_root_solver = algebraic_root_solver
 
+    @property
+    def y0(self):
+        if not hasattr(self, "y0_list") or self.y0_list is None:
+            return None
+        elif len(self.y0_list) == 1:
+            return self.y0_list[0]
+        else:
+            raise ValueError(
+                "Model contains multiple initial states. Access using y0_list instead."
+            )
+
     def get_parameter_info(self, by_submodel=False):
         """
         Extracts the parameter information and returns it as a dictionary.

src/pybamm/simulation.py

@@ -379,7 +379,6 @@ def solve(
         showprogress=False,
         inputs=None,
         t_interp=None,
-        initial_conditions=None,
         **kwargs,
     ):
         """
@@ -542,7 +541,6 @@ def solve(
                 inputs=inputs,
                 t_interp=t_interp,
                 **kwargs,
-                initial_conditions=initial_conditions,
             )
 
         elif self.operating_mode == "with experiment":

src/pybamm/solvers/algebraic_solver.py

@@ -78,7 +78,7 @@ def tol(self):
     def tol(self, value):
         self._tol = value
 
-    def _integrate(self, model, t_eval, inputs_dict=None, t_interp=None):
+    def _integrate_single(self, model, t_eval, inputs_dict, y0):
         """
         Calculate the solution of the algebraic equations through root-finding
 
@@ -90,14 +90,21 @@ def _integrate(self, model, t_eval, inputs_dict=None, t_interp=None):
             The times at which to compute the solution
         inputs_dict : dict, optional
             Any input parameters to pass to the model when solving
+        y0 : array-like
+            The initial conditions for the model
+
+        Returns
+        -------
+        :class:`pybamm.Solution`
+            A Solution object containing the times and values of the solution,
+            as well as various diagnostic messages.
         """
         inputs_dict = inputs_dict or {}
         if model.convert_to_format == "casadi":
             inputs = casadi.vertcat(*[x for x in inputs_dict.values()])
         else:
             inputs = inputs_dict
 
-        y0 = model.y0
         if isinstance(y0, casadi.DM):
             y0 = y0.full()
         y0 = y0.flatten()