[Users] question about ML_BSSN::fixAdvectionTerms

[Slinker, Kyle Patrick]

Hello,

I'm wondering if anybody can tell me about the
ML_BSSN::fixAdvectionTerms parameter (which I think was new in
Somerville). I have been trying to reproduce some old results and
discovered this morning that having this parameter set to "off" is what
was causing the discrepancy.

What does it do? The description "Modify driver and advection terms to
work better?" is vague enough I don't know what to make of it. From
McLachlan_BSSN.m it looks like it's switching how the advection terms in
the 1+log and Gamma-driver conditions are handled. What changes is it
making to these equations? And what is the purpose of them? If setting
the parameter to "on" reproduces old results (and if it lives up to its
name and fixes things), should "on" be the default behavior?

Thanks.

Kyle Slinker