Simulation with explicit experiment and irreversibe plating fails

[DavidMStraub]

• PyBaMM version: Current develop
• Python version: 3.8.5

Describe the bug

Error:

RuntimeError: .../casadi/core/function_internal.hpp:1257: Input 1 (i1) has mismatching shape. Got 141-by-1. Allowed dimensions, in general, are:
 - The input dimension N-by-M (here 122-by-1)
 - A scalar, i.e. 1-by-1
 - M-by-N if N=1 or M=1 (i.e. a transposed vector)
 - N-by-M1 if K*M1=M for some K (argument repeated horizontally)
 - N-by-P*M, indicating evaluation with multiple arguments (P must be a multiple of 1 for consistency with previous inputs)

To Reproduce
Steps to reproduce the behaviour:

import pybamm

options = {"lithium plating": "irreversible"}
model = pybamm.lithium_ion.SPMe(options=options)

experiment = pybamm.Experiment(
    [
        "Discharge with 1 C for 30 minutes",
        "Rest for 30 minutes",
    ]
)

solver = pybamm.CasadiSolver("fast with events")

parameter_values = model.default_parameter_values.copy()
parameter_values.update(
    {
        "Lithium metal partial molar volume [m3.mol-1]": 1.30e-5,
        "Exchange-current density for plating [A.m-2]": 0.001,
        "Initial plated lithium concentration [mol.m-3]": 0,
        "Typical plated lithium concentration [mol.m-3]": 1000,
    },
    check_already_exists=False
)

sim = pybamm.Simulation(model, experiment=experiment, solver=solver, parameter_values=parameter_values)
sim.solve()

Expected behaviour

No error

Additional context

• Possibly related to Solving 2D pouch model with explicit experiment fails #1547.
• Using only a single step in the experiment removes the error
• Removing lithium plating removes the error

[brosaplanella]

The issue is with the x-averaging of the plating model. I will open a separate issue, but for the moment you can replace the line where you define the model by

model = pybamm.lithium_ion.SPMe(build=False)
model.submodels["negative lithium plating"] = pybamm.lithium_plating.IrreversiblePlating(model.param, "Negative", False)
model.build_model()

[DavidMStraub]

Thanks! Fix worked (I had to remove the "Negative" from IrreversiblePlating).

[valentinsulzer]

It should still work with the x-averaged form, there is just a bug in how multiple steps are set up. I thought I had fixed it but don't know where that branch went