From b437da8b8dcaafe5c8299e24ea63246faa955079 Mon Sep 17 00:00:00 2001
From: David Sagan <dcs16@cornell.edu>
Date: Thu, 12 Dec 2024 23:04:49 -0500
Subject: [PATCH] Fix update of p0c.

---
 bmad/ptc/update_fibre_from_ele.f90 | 10 +++++++---
 1 file changed, 7 insertions(+), 3 deletions(-)

diff --git a/bmad/ptc/update_fibre_from_ele.f90 b/bmad/ptc/update_fibre_from_ele.f90
index 2ce2f2245..d6ef9228a 100644
--- a/bmad/ptc/update_fibre_from_ele.f90
+++ b/bmad/ptc/update_fibre_from_ele.f90
@@ -27,8 +27,9 @@ subroutine update_fibre_from_ele (ele, survey_needed)
 type (element), pointer :: mag
 type (elementp), pointer :: magp
 type (magnet_chart), pointer :: mp, mpp
+type (work) ptc_work
 
-real(rp) value, hk, vk, phi_tot, fh, volt
+real(rp) value, hk, vk, phi_tot, fh, volt, delta_p
 real(rp) a_pole(0:n_pole_maxx), b_pole(0:n_pole_maxx)
 real(rp) a_ptc(0:n_pole_maxx), b_ptc(0:n_pole_maxx)
 real(rp), pointer :: val(:)
@@ -44,6 +45,7 @@ subroutine update_fibre_from_ele (ele, survey_needed)
 branch => pointer_to_branch(ele)
 fib => ele%ptc_fibre
 val => ele%value
+FEED_P0C = .true.
 
 mag  => fib%mag
 magp => fib%magp
@@ -51,6 +53,10 @@ subroutine update_fibre_from_ele (ele, survey_needed)
 mp => mag%p
 mpp => magp%p
 
+ptc_work = fib
+ptc_work = 1e-9_rp * val(p0c$) - mp%p0c 
+fib = ptc_work
+
 cavity_type = not_set$
 if (ele%key == rfcavity$ .or. ele%key == lcavity$) then
   cavity_type = nint(ele%value(cavity_type$))
@@ -67,8 +73,6 @@ subroutine update_fibre_from_ele (ele, survey_needed)
   call set_real_all (mp%lc, mpp%lc, val(l$))
 endif
 
-call set_real_all (mp%p0c, mpp%p0c, 1e-9_rp * val(p0c$))
-
 !
 
 if (ele%key == marker$) return