rdemaria / pysixtrack

Reference sixtrack tracking engine in pure python

pysixtrack

Reference sixtrack tracking engine in pure python

pysixtrack's Issues

p0c setter gives an error

Here an example:

In [7]: ps_part.p0c = 7000*1e9
---------------------------------------------------------------------------
NameError                                 Traceback (most recent call last)
<ipython-input-7-6b6e194dff1d> in <module>()
----> 1 ps_part.p0c = 7000*1e9

~/Desktop/WeakStrongDevelopment/pysixtrack/pysixtrack/particles.py in p0c(self, p0c)
    282         new = self._f1(self.mass0, p0c)
    283         self._update_ref(*new)
--> 284         self._update_particles(*new)
    285 
    286     energy0 = property(lambda self: self._energy0)

~/Desktop/WeakStrongDevelopment/pysixtrack/pysixtrack/particles.py in _update_particles(self, mass0, beta0, gamma0, p0c, energy0)
    328             Energy = self.Energy
    329             Pc = self.Pc
--> 330             mratio = mass / mass0
    331             self._mratio = mratio
    332             self._chi = self._qratio / mratio

NameError: name 'mass' is not defined

Issue with Line constructor and defaults

In [2]: import pysixtrack

In [3]: pysixtrack.Line()
Out[3]: Line(elements=[])

In [4]: l1 = pysixtrack.Line()

In [5]: l1.elements.append('hello')

In [6]: l2 = pysixtrack.Line()

In [7]: l2
Out[7]: Line(elements=['hello'])

loader_mad: collimator, kicker, elseparator

For now, loader_mad knows about rcollimator but in general (at least in recent MAD-X versions) it should be collimator. Let's also add kicker and elseparator (at least they are present in the SIS100 lattice, could be useful to translate them to hkicker and vkicker resp. a zero drift!).

expose slicing tool in BeamBeam6D

Particle definitions against pyblep

We should clean up the names in the particle in pysixtrack and pysixtracklib to use the same as pyblep.

improved error handling

To be improved before merging:

1. integrate error handling for PySixTrack already into loader_madx functionality -- by reading out errors via new cpymad functionality, e.g.:

>>> seq = madx.sequence.XYZ
>>> multipole = seq.expanded_elements[0]
>>> multipole.align_errors
AlignError(dx=-2.1754812916408347e-05, dy=-6.556356908596416e-06, 
ds=0.0, dphi=0.0, dtheta=0.0, dpsi=0.0, mrex=0.0, mrey=0.0, mredx=0.0, 
mredy=0.0, arex=0.0, arey=0.0, mscalx=0.0, mscaly=0.0)

>>> multipole.field_errors.dkn
[0.0,
 1.1472076071601915e-06,
 5.002980147857331e-06,
 0.013090083041168831,
 -0.19713806015162913,
 -73.91912412030126,
 -9.796705181638819,
 0.0,
(...)
 0.0]

2. possibly remove current approach with error table read out (more cumbersome approach, bloated functionality in PySixTrack)

Originally posted by @aoeftiger in #28 (comment)

Multipole knl & ksl extensibility

For an instantiated elements.Multipole, it'd be really useful to assign higher-order magnet strengths even if they were not declared at instantiation.

e.g.

m = pysixtrack.elements.Multipole(knl=[0])
m.knl[1] = 1e-2 # currently raises an IndexError

This could be implemented based on abc.Sequence similarly to the cpymad.madx.ArrayAttribute approach -- which comes in really handy in cpymad.

This feature would be useful for manipulation of Multipoles in particular in view of adding error components to an existing lattice.

Current version on PyPI does not contain recent changes

Most notably, the BeamMonitor introduced in commit 3c0dceb is not present in the version installable via pip, causing pysixtracklib to fail on a vanilla installation.