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Table of Contents
Name | Direction | Type | Default | Description |
---|---|---|---|---|
Filename | Input | string | Mandatory | Path to the polarization efficiency file. |
OutputWorkspace | Output | MatrixWorkspace | Mandatory | An output workspace containing the efficiencies at the reference workspace’s wavelength points. |
WavelengthReference | Input | MatrixWorkspace | Mandatory | A reference workspace to get the wavelength axis from. |
This algorithm loads reflectometry polarization efficiency data from ILL’s IDL-style text files. The output is a workspace with the efficiency factors calculated for each bin or point in the first spectrum of the WavelengthReference workspace. The output workspace is populated with five histograms carrying the following vertical axis labels:
P1
P2
F1
F2
Phi
Note, that the order of the histograms in the output workspace is unspecified. The histograms should be identified by the above labels instead.
The errors in the output histograms are estimated by multiplying the efficiencies by constant factors.
Note
To run these usage examples please first download the usage data, and add these to your path. In Mantid this is done using Manage User Directories.
Example - Loading sample data and corresponding efficiencies
# We need reference wavelengths. Lets use some real data for that.
# Load direct beam for detector angle calibration.
db = LoadILLReflectometry(Filename='ILL/D17/317369.nxs',
XUnit='TimeOfFlight')
rb = LoadILLReflectometry(Filename='ILL/D17/317370.nxs',
Measurement='ReflectedBeam',
BraggAngle=0.8,
XUnit='TimeOfFlight')
# Sum over the reflected beam.
rb_grouped = GroupDetectors(rb, GroupingPattern='201-203')
rb_in_wavelength = ConvertUnits(rb_grouped, Target='Wavelength')
rb_cropped = CropWorkspace(rb_in_wavelength, XMin=0)
pol_factors = LoadILLPolarizationFactors(Filename='ILL/D17/PolarizationFactors.txt',
WavelengthReference=rb_cropped)
# Grab the vertical axis.
axis = pol_factors.getAxis(1)
axisSize = axis.length()
factors = []
for i in range(axisSize):
factors.append(axis.label(i))
print("The following factors were loaded from the file: {}".format(factors))
Output:
The following factors were loaded from the file: ['F1', 'F2', 'P1', 'P2', 'Phi']
Categories: AlgorithmIndex | DataHandling\Text | ILL\Reflectometry
C++ header: LoadILLPolarizationFactors.h (last modified: 2021-03-31)
C++ source: LoadILLPolarizationFactors.cpp (last modified: 2021-03-31)