Naming of the keyword arguments of simple_ring about at HOT 6 CLOSED

Anybody willing to do something about that ? Or shall I do it ?

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I think @lcarver said he would do it, but most likely not for matlab...

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Fine. Apart from naming, better being done before the function gets widely used, all my other suggestions are neither critical nor urgent, just ideas!

For Matlab, same: not urgent, I might do it some time later…

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Sorry, I was off yesterday. I will do it for your first 2 points. But yes, I will not do the MATLAB! Although I am not sure of the following point:

"one could even accept a Σ-matrix, which can replace alpha*, beta*, emit*, sigma_dp*.`"

This is not clear to me.

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This is not clear to me.

The Σ-matrix (beam matrix as returned by ohmienvelope, for instance) contains all the optics and emittance information. So, with Σ and tunes, you can get the M₆₆ matrix and the emittances. Adding the damping times, you have everything.

Here, since the longitudinal motion is treated apart, I think we should use a 4D twiss_in input, generate a 4x4 transfer map and add the 44, 45, 54 and 55 terms as you do it now.

So to start from the R matrix in twiss_in, the easiest is first to build Σ = ε₁.R₁ + ε₂.R₂, then use a_matrix to get the A matrix, use the tunes to generate the rotation matrix S and finally build M₄₄ = A.S.A^-1

If starting directly from Σ, a_matrix will also return the needed emittances.

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fixed in #655

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