Fig 1. The four relative metrics as a function of the key parameter N (the number of eigenfunctions), for four selected values of α.

The solution is computed for all values of α on the time interval [0,500 ms] with a uniform time step Δt = 0.01 ms. All relative errors are evaluated by comparing the solution for a specific combination of α and N with the solution obtained for the same α when N = 3200. In all simulations, the stimulus I _stim = 40 μA⋅cm⁻³ was applied on [0,0.05 cm] at t _stim = 10 ms for two consecutive milliseconds and then removed.