Changes introduced in Xsuite v0.2.0

Significant changes are introduced with Xsuite v0.2.0 and the corresponding subpackages Xobjects v0.1.0, Xtrack v0.4.0, Xpart v0.2.0 and Xfields v0.3.0 .

The main goals of these changes are to simplify the user interface bases on the (precious!) feedback from early users and developers and to ease the implementation of new features in the near future.

We are trying to adapt and improve the user interface as much as possible at this early stage of development to minimize future changes, which would affect a larger number of users and a larger amount of user’s code.

Changes to the interface

Most relevant changes to the interface are the following:

  • The xline package is removed

    • The class xline.Line is replaced by xtrack.Line for the creation and import of machine lattices (see Getting started).

    • Beam elements are created using directly the xtrack classes (xtrack.Drift, xtrack.Multipole, xtrack.Cavity, etc.) instead of of the xline ones (xline.Drift, xline.Multipole, xtrack.Cavity).

  • There is only one Particles class within Xsuite, which can be imported from xpart package. Therefore xline.Particles and xtrack.Particles should be replaced by xpart.Particles.

  • The sequence argument of the tracker class was renamed line to be consistent with the naming used elsewhere.

  • The PyHEADTAIL interface is moved from xtrack to xpart (see Interface to PyHEADTAIL)

  • The random number generators are moved from xtrack to xpart.

  • The method xtrack.Line.from_json has been removed. A line can be loaded from a json file by:

import json
with open(''line.json", "r") as fid:
    line = xtrack.Line.from_dict(json.load(fid))

New features

  • The xtrack.Tracker class has new methods for closed-orbit search and one-turn-matrix calculation with finite differences.

  • Added xpart.build_particles function allowing to build a particles object from a reference particles plus arrays with geometric or normalized coordinates.