pymchelper.axis module

class pymchelper.axis.AxisId

Bases: enum.IntEnum

An enumeration.

diff1 = 3

diff2 = 4

x = 0

y = 1

z = 2

class pymchelper.axis.MeshAxis

Bases: pymchelper.axis.MeshAxis

Scoring mesh axis data.

It can represent an axis variety of scorers: x,y or z in cartesian scoring, r, rho or z in cylindrical. An axis represents a sequence of n numbers, defining linear or logarithmic binning. This sequence of numbers is not stored in the memory, but can be generated using data property method. min_val is lowest bin left edge, max_val is highest bin right edge name can be used to define physical quantity (i.e. position, energy, angle). unit gives physical units (i.e. cm, MeV, mrad).

MeshAxis is constructed as immutable data structure, thus it is possible to set field values only upon object creation. Later they are available for read only.

>>> x = MeshAxis(n=10, min_val=0.0, max_val=30.0, name="Position", unit="cm", binning=MeshAxis.BinningType.linear)
>>> x.n, x.min_val, x.max_val
(10, 0.0, 30.0)
>>> x.n = 5
Traceback (most recent call last):
...
AttributeError: can't set attribute

binning field (use internal BinningType.linear or BinningType.logarithmic) can distinguish log from linear binning

class BinningType

Bases: enum.IntEnum

type of axis generator

linear = 0

logarithmic = 1

data

Generates linear or logarithmic sequence of n numbers.

These numbers are middle points of the bins defined by n, min_val and max_val parameters.

>>> x = MeshAxis(n=10, min_val=0.0, max_val=10.0, name="X", unit="cm", binning=MeshAxis.BinningType.linear)
>>> x.data
array([ 0.5,  1.5,  2.5,  3.5,  4.5,  5.5,  6.5,  7.5,  8.5,  9.5])

Binning may also consist of one bin: >>> x = MeshAxis(n=1, min_val=0.0, max_val=5.0, name=”X”, unit=”cm”, binning=MeshAxis.BinningType.linear) >>> x.data array([ 2.5])

Logarithmic binning works as well, middle bin points are calculated as geometrical mean. Here we define 3 bins: [1,4], [4,16], [16,64]. >>> x = MeshAxis(n=3, min_val=1.0, max_val=64.0, name=”X”, unit=”cm”, binning=MeshAxis.BinningType.logarithmic) >>> x.data array([ 2., 8., 32.])

For the same settings as below linear scale gives as expected different sequence: >>> x = MeshAxis(n=3, min_val=1.0, max_val=64.0, name=”X”, unit=”cm”, binning=MeshAxis.BinningType.linear) >>> x.data array([ 11.5, 32.5, 53.5])

For logarithmic axis min_val has to be positive: >>> x = MeshAxis(n=3, min_val=-2.0, max_val=64.0, name=”X”, unit=”cm”, binning=MeshAxis.BinningType.logarithmic) >>> x.data Traceback (most recent call last): … Exception: Left edge of first bin (-2) is not positive

Returns: