Julian Hall
I don't think that the presolve is looking at the consequences of poor scaling, so you've not missed anything @douglaswaynepotter, and I'm pleased to hear of your successful use of...
We will be introducing a system of callbacks into HiGHS, but not on a per-iteration basis for simplex at least.
I can see that you don't want to do this, but a "per iteration" callback would be a performance hit that we can't accept. At present there is a logging...
LP and MIP solver callbacks are now implemented
We may be able to accommodate this - what's your view @galabovaa? - but why do you want to build HiGHS in anything other than `Release`?
Thanks. I get anomalous behaviour as the cost parameter increases, but not quite the same as you. I'm using v1.4.1, but on Linux, not MacOS. I suspect that the inherent...
The issue isn't related to presolve, as aberrant behaviour still occurs with `--presolve=off`. Indeed, without presolve the solver stalls, suggesting a problem solving nodes with the LP solver.
All I can say is that the multitasking environment (not written by me, I should add) was WIP for most of 2022, so it's quite possible that this race condition...
I, too, reduced `mip_rel_gap` to zero and got this outcome. Indeed, the termination criterion is that at least one of the two tolerances is satisfied: just to give flexibility to...
Thanks, but this won't work when (for example) one of `lower` and `upper` is infinite. I'll have a look, but changes at this level of the HiGHS solvers have to...