Why
res and hyper_res aren't just runtime toggles, they pick which compile-time Equations template gets built (Equations::resistivity/hyperResistivity in godunov_utils.hpp, gated by if constexpr). So if you set eta=0.001 but forget res=True, the simulation silently runs with no resistive term compiled in at all — no warning, nothing. Same for nu/hyper_res. Hybrid doesn't have this problem since resistivity/hyper_resistivity are just values there, no separate switch.
What
Default res/hyper_res from eta/nu in check_mhd_terms (pyphare/pharein/simulation.py) when not explicitly given, so setting a nonzero coefficient is enough to turn the term on. Keep them settable manually for the rare case someone wants the term compiled in with a zero coefficient.
Ideas on how (optional)
res = kwargs.get("res", kwargs.get("eta", 0.0) > 0.0)
hyper_res = kwargs.get("hyper_res", kwargs.get("nu", 0.0) > 0.0)Alternatives considered
No response
Additional context
No response
Why
res and hyper_res aren't just runtime toggles, they pick which compile-time Equations template gets built (Equations::resistivity/hyperResistivity in godunov_utils.hpp, gated by if constexpr). So if you set eta=0.001 but forget res=True, the simulation silently runs with no resistive term compiled in at all — no warning, nothing. Same for nu/hyper_res. Hybrid doesn't have this problem since resistivity/hyper_resistivity are just values there, no separate switch.
What
Default res/hyper_res from eta/nu in check_mhd_terms (pyphare/pharein/simulation.py) when not explicitly given, so setting a nonzero coefficient is enough to turn the term on. Keep them settable manually for the rare case someone wants the term compiled in with a zero coefficient.
Ideas on how (optional)
Alternatives considered
No response
Additional context
No response