Utility Classes

Various classes are provided for the construction of BDSIM input definitions. There are classes defined in pybdsim.Builder that allow writing of an object without any checks. Also, there are some specialised classes listed here that exist in pybdsim that include some checking and utility functions.

Once a class is constructed, converting to a string in Python will produce a string in BDSIM input syntax that can be written to a file.

General Classes

pybdsim.Builder.Aperture
pybdsim.Builder.Atom
pybdsim.Builder.BLM
pybdsim.Builder.CavityModel
pybdsim.Builder.Crystal
pybdsim.Builder.Field
pybdsim.Builder.Material
pybdsim.Builder.Query
pybdsim.Builder.Region
pybdsim.Builder.SamplerPlacement
pybdsim.Builder.Scorer
pybdsim.Builder.ScorerMesh
pybdsim.Builder.Tunnel
pybdsim.Builder.XSecBias

These all work in the same way. The are constructed with the first argument being a name, then paramter value pairs as keyword arguments (“kwargs”). e.g.

>>> a = pybdsim.Builder.Aperture('aperDef1', aper1=3, aper2=(2.5,'cm'))
>>> str(a)
    'aperDef1: aperture, aper1=3, aper2=2.5*cm;\n'

Acceptable types are int, float, str, list, tuple(number, str). In the case of a tuple (e.g. ()), it should contain 2 items and the second is the units string.

An example with a list:

>>> sp = pybdsim.Builder.SamplerPlacement('z350mL',
                                          z=(350,'m'),
                                          shape="rectangular",
                                          aper1=(5,'m'),
                                          aper2=(5,'m'),
                                          partID=[13,-13])
>>> str(sp)
    'z350mL: samplerplacement, shape="rectangular", partID={13,-13}, aper1=5.0*m, z=350.0*m, aper2=5.0*m;\n'

Note

The keyword arguments are not checked. One could write “bananas=5” and it would be used, but ultimately would have no meaning to BDSIM.

Specialised Classes

Beam.Beam

This beam class represents a beam definition in gmad syntax. The class has ‘setter’ functions that are added dynamically based on the distribution type selected.:

>>> b = pybdsim.Beam.Beam()
>>> b.SetParicleType("proton")
>>> b.SetDistributionType("reference")

Options.Options

This class provides the set of options for BDSIM. Please see pybdsim.Options module for more details.

XSecBias.XSecBias

This class provides the definition process biasing in BDSIM. Please see pybdsim.XSecBias module for more details.