processed spatial variables

[tobykirk]

We would like to process a SpatialVariable (into a "ProcessedSpatialVariable") to extract the limits and construct a np.array of points between them using linspace (or otherwise). This would allow easy plotting over any domain of choice.

[martinjrobins]

might be able to make ProcessedVariable automatically detect if the variable is a spatial one and use a default np.array of points the same as the mesh on that domain?

[rtimms]

you can now do this (see PR #1020) e.g.

import pybamm
import numpy as np

model = pybamm.lithium_ion.SPM()

sim = pybamm.Simulation(model)
solution = sim.solve()
r_n = solution["r_n [m]"]
r_n(r=np.linspace(0, 1, 10))

to get 10 linearly spaced points in the negative particle