#1195: Modify bisection algorithm in EOS_Omni's nuc_eos ------------------------------------+--------------------------------------- Reporter: eschnett | Owner: Type: enhancement | Status: review Priority: major | Milestone: Component: EinsteinToolkit thorn | Version: Resolution: | Keywords: ------------------------------------+---------------------------------------
Comment (by eschnett):
Christian Ott tells me that he is currently re-designing part of this algorithm anyway. We should therefore wait before modifying the code.
Ian: Yes, the reason is that the temperature is more evenly distributed in log T than in T.
This routine is a generic EOS table lookup routine, and doesn't know anything about past timelevels or neighbouring points. This routine already uses log T for many operations. It only goes to great lengths to switch back to T, apply the bisection step, and then switch back to log T. My argument is that this additional complication is not necessary, and likely even slows down convergence.
Frank: This routine is not a generic bisection routine. It is supposed to find the temperature corresponding to a particular internal energy, since the EOS table is provided in terms of log T, while the code passes in the internal energy.
I did not add calls to log, I removed them. If you go to https://trac.einsteintoolkit.org/attachment/ticket/1195/eos-log.diff, then the green lines are added, not the red ones.