R of x gets passed dimensionless x

[rtimms]

The functions R_n_of_x etc. get passed dimensionless x but this doesn't get scaled when passed to the FunctionParameter which depends on x [m], e.g.

        inputs = {"Through-cell distance (x_n) [m]": x}
        return pybamm.FunctionParameter("Negative particle distribution in x", inputs)

should be

        inputs = {"Through-cell distance (x_n) [m]": x * self.L_x}
        return pybamm.FunctionParameter("Negative particle distribution in x", inputs)

since thicknesses are scaled by L_x

[rtimms]

actually, more consistent with other things (e.g. initial solid concentration) to write it as a function of dimensionless through-cell position, i.e.

        inputs = {"Dimensionless through-cell position (x_n)": x}
        return pybamm.FunctionParameter("Negative particle distribution in x", inputs)

[valentinsulzer]

Looking at this again, why do we separate the particle radius and its dependence in x into two separate parameters? Wouldn't it be clearer if it was always a single (dimensional input, dimensional output) parameter?

[rtimms]

yeah that would be cleaner. i think we kept it separate so that we had a reference radius to use in the non-dimensionlisation, though i guess you just take the average for that

[valentinsulzer]

Yeah, or evaluate at x=0 and x=1 (might have issues with the average not being defined until discretisation)