Add coupling representation of Ripken-Wolski-Forest

[mattsignorelli]

The current default representation of coupling can cause the "beta function" to blow up (e.g. #478) and is not physically measurable. The coupling representation of Ripken-Wolski-Forest does not have this issue and should be the default. See section 43.3 of the attached.

bmad_43-1.pdf

[DavidSagan]

@mattsignorelli This is a huge breaking change. Just implementing RWF as a non-default option will take some work. I am going to close this for now and this issue can be reopened after some discussion.

[mattsignorelli]

OK, but why would this be so much work as a non default? It’s just a simple matrix calculation using the map and linear normalizing map. The calculation for all of these quantities is only a couple lines of code, and I also saw Xsuite includes Etienne’s de Moivre representation as an option according to their paperIn fact there is already a function in FPP “compute lattice functions” that does it for you I feel at the least we should leave the issue open as an “enhancement”Sent from my iPhoneOn Aug 10, 2024, at 4:21 PM, David Sagan ***@***.***> wrote: @mattsignorelli This is a huge breaking change. Just implementing RWF as a non-default option will take some work. I am going to close this for now and this issue can be reopened after some discussion. —Reply to this email directly, view it on GitHub, or unsubscribe.You are receiving this because you were mentioned.Message ID: ***@***.***>