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Add eigentune calculation to MATRIX_Lattice #151

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Merged
austin-hoover merged 5 commits into from
Oct 13, 2026
Merged

Add eigentune calculation to MATRIX_Lattice #151

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ed55c57
Add eigentune calculation to MATRIX_Lattice
austin-hoover Sep 15, 2026
06191fa
Merge branch 'main' into matrix-lattice-eigentunes
austin-hoover Oct 9, 2026
3892da1
Add tests for eigentune calculation
austin-hoover Oct 9, 2026
a253883
Merge branch 'PyORBIT-Collaboration:main' into matrix-lattice-eigentunes
austin-hoover Oct 9, 2026
e448722
Merge branch 'PyORBIT-Collaboration:main' into matrix-lattice-eigentunes
austin-hoover Oct 13, 2026
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15 changes: 14 additions & 1 deletion py/orbit/matrix_lattice/MATRIX_Lattice.py
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Original file line number Diff line number Diff line change
Expand Up @@ -9,7 +9,7 @@
"""
import os
import math

import numpy as np

# import bunch
from orbit.core.bunch import Bunch
Expand Down Expand Up @@ -114,6 +114,8 @@ def getRingParametersDict(self, momentum, mass):
mt = self.oneTurnMatrix
res_dict["fractional tune x"] = None
res_dict["fractional tune y"] = None
res_dict["fractional tune 1"] = None
res_dict["fractional tune 2"] = None
res_dict["alpha x"] = None
res_dict["alpha y"] = None
res_dict["beta x [m]"] = None
Expand Down Expand Up @@ -145,6 +147,17 @@ def getRingParametersDict(self, momentum, mass):
res_dict["fractional tune x"] = nux
res_dict["fractional tune y"] = nuy

# Eigentunes
M = np.array([[mt.get(i, j) for j in range(4)] for i in range(4)])
eigvals, _ = np.linalg.eig(M)
eigvals = eigvals[[0, 2]]
cos_phi = np.real(eigvals)
phi = np.arccos(cos_phi)
nu = phi / (2.0 * np.pi)
nu %= 1.0
res_dict["fractional tune 1"] = float(nu[0])
res_dict["fractional tune 2"] = float(nu[1])

# Alpha, beta, gamma
beta_x = mt.get(0, 1) / sin_phi_x
beta_y = mt.get(2, 3) / sin_phi_y
Expand Down
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