#487: SimFactory should allow steering of parameters between restarts --------------------------+------------------------------------------------- Reporter: hinder | Owner: eschnett Type: enhancement | Status: new Priority: major | Milestone: Component: SimFactory | Version: Resolution: | Keywords: --------------------------+-------------------------------------------------
Comment (by bmundim):
I should say that this is the main reason I haven't switched to SimFactory yet. I probably have already mentioned this before, but I should repeat here, that I commonly output a different number of variables between the initial data and evolution parts of the simulation. I find it useful for initial inspection (to see if everything is all right before spending thousands of SUs). It would be really great if SimFactory allows me to steer parameters so I don't need to hack into its internals to force a change of parameters.
Also I can think of other examples where it could be useful: the case when you want to find the horizons with a different frequency in the inspiral phase than in the plunge and merger phases. Or if someone else has a very expensive analysis routine that would be turned on only at a particular time of the simulation (that we don't know when to do so in advance for a new simulation). Another example: your simulation quits with nans and you find out that you can avoid that by decreasing the courant factor or maybe by enlarging an AH mask in a hydro simulation, it would be very useful to still do so easily with SimFactory. Currently I don't think it is possible without hacking it. Since the other alternative, running my own scripts, gives me more freedom, I find it hard to justify all the time necessary to learn yet another tool (that may not give me such a freedom). Erik's ideal of a simulation unfortunately is currently too unrealistic, since all these eventual tweaks in the parameters would need to be some how dealt with automatically. I don't think that's possible.
So, said that, maybe we can still use the same simulation infrastructure and if we need to change the parameter file for some reason, that would be stored in the appropriate checkpoint directory and tagged accordingly. This way the simulation is still easily reproducible by someone else. What do you think?