[Fix] BeamLoadingEquilibrium

Change location of update_rho()

mbtrack2/utilities/beamloading.py

@@ -107,7 +107,6 @@ class BeamLoadingEquilibrium():
 
     def center_of_mass(self):
         """Return center of mass position in [s]"""
-        self.update_rho()
         CM = np.average(self.z0, weights=self.rho0)
         return CM / c
 
@@ -166,6 +165,7 @@ class BeamLoadingEquilibrium():
         else:
             self.F = x[::2]
         self.PHI = x[1::2]
+        self.update_rho()
 
         # Compute system
         if self.auto_set_MC_theta: