When APVETO=TRUE set phase relative to arrival time
The phase of a cavity at time t is given by
\varphi (t) = \omega \cdot t + \varphi_{\text{LAG}} + \varphi_0.When running the auto-phasing algorithm we set the phase of a cavity relative to the phase at which a cavity yields maximal energy. Thus \varphi_0 = \varphi_{\text{max}}. In some cases we want or have to set APVETO=TRUE. Currently we set \varphi_0 = 0 but we should set it such that \varphi (t_{\text{ELEMEDGE}}) = 0. Here t_{\text{ELEMEDGE}} is the time at which the reference particle enters the element (either physically or alternatively the region in which field of the cavity is non-zero).