From 4770618a6dda544faa553345decaad1368dba01b Mon Sep 17 00:00:00 2001
From: gubaidulinvadim <gubaidulinvadim@gmail.com>
Date: Tue, 30 Jul 2024 11:47:54 +0200
Subject: [PATCH] changed chromaticity computation in _compute_chro() of
transverse_map_sector_generator(). Now it can compute arbitrary order of
chromaticity from AT.
---
mbtrack2/tracking/element.py | 21 +++++++--------------
1 file changed, 7 insertions(+), 14 deletions(-)
diff --git a/mbtrack2/tracking/element.py b/mbtrack2/tracking/element.py
index d218e8e..7e36e81 100644
--- a/mbtrack2/tracking/element.py
+++ b/mbtrack2/tracking/element.py
@@ -404,22 +404,15 @@ def transverse_map_sector_generator(ring, positions):
else:
import at
- def _compute_chro(ring, pos, dp=1e-4):
+ def _compute_chro(ring, pos, dp=1e-4, order=4):
lat = deepcopy(ring.optics.lattice)
lat.append(at.Marker("END"))
- N = len(lat)
- refpts = np.arange(N)
- (*elem_neg_dp, ) = at.linopt2(lat, refpts=refpts, dp=-dp)
- (*elem_pos_dp, ) = at.linopt2(lat, refpts=refpts, dp=dp)
-
- s = elem_neg_dp[2]["s_pos"]
- mux0 = elem_neg_dp[2]["mu"][:, 0]
- mux1 = elem_pos_dp[2]["mu"][:, 0]
- muy0 = elem_neg_dp[2]["mu"][:, 1]
- muy1 = elem_pos_dp[2]["mu"][:, 1]
-
- Chrox = (mux1-mux0) / (2*dp) / 2 / np.pi
- Chroy = (muy1-muy0) / (2*dp) / 2 / np.pi
+ fit, dpa, tune = at.physics.nonlinear.chromaticity(lat,
+ method='linopt',
+ dpm=0.02,
+ n_points=100,
+ order=order)
+ Chrox, Chroy = fit
chrox = np.interp(pos, s, Chrox)
chroy = np.interp(pos, s, Chroy)
--
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