The simulation state combines fields, material, coefficients, grid parameters, and sources. A reset deliberately clears only the advancing fields and clock:

void Fdtd_EzSimReset(Fdtd_EzSim *sim)
{
    Fdtd_EzStateReset(sim->fsim_state);
    Fdtd_EzFieldsReset(sim->fsim_fields);
}

Material, coefficients, execution mode, and source registrations remain in place. This lets benchmark repetitions restart the same setup without reconstructing it.

In contrast, consecutive Fdtd_EzSimRun(sim, nsteps) calls continue from the current fields and step counter. Fdtd_EzSimGetTime() returns that counter, while Fdtd_EzSimGetDt() supplies seconds per step. CSV output saves fields and material for later restoration, but not source callbacks.

Source: fdtd_ez_sim.c.