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ConvertCWSDMDtoHKL v1¶

Summary ¶

Convert constant wavelength single crystal diffractomer’s datain MDEventWorkspace and in unit of Q-sample to the HKL space by UB matrix.

Properties ¶

Name	Direction	Type	Default	Description
InputWorkspace	Input	MDEventWorkspace	Mandatory	Name of the input MDEventWorkspace that stores detectors counts from a constant-wave powder diffraction experiment.
PeaksWorkspace	Input	PeaksWorkspace		Input Peaks Workspace
UBMatrix	Input	dbl list		A comma seperated list of doubles for UB matrix from (0,0), (0,1)… (2,1),(2,2)
OutputWorkspace	Output	MDEventWorkspace	Mandatory	Name of the output MDEventWorkspace in HKL-space.
QSampleFileName	Input	string		Name of file for sample sample.
HKLFileName	Input	string		Name of file for HKL.

This algorithms is to convert an MDEventWorkspace in Q-sample coordinate to HKL coordindate for a reactor-based four-circle single crystal diffractometer. Meanwhile, the algorithm is able to export the MDEvents to file.

Outline of algorithm ¶

Convert MDEvent’s coordinate system
Export MDEvent in Q-sample coordinate and HKL coordinate.

Inputs ¶

InputWorkspace is an MDEventWorkspace ???.

PeakWorkspace is an optional input as in many cases especially after calculating UB matrix, …

UBMatrix is ???.

Outputs ¶

The output is an MDEventWorkspace that… ..

MDEvent ¶

Each MDEvent in output MDEventWorkspace contain * H * K * L * Signal * Error * Detector ID * Run Number

Compare with ConvertMD ¶

Comparing with ????

Usage ¶

Example - Convert detector counts of an HB3A’s measurement to HKL.

# Create input table workspaces for experiment information and virtual instrument parameters
CollectHB3AExperimentInfo(ExperimentNumber='406', ScanList='298', PtLists='-1,22',
    DataDirectory='',
    GenerateVirtualInstrument=False,
    OutputWorkspace='ExpInfoTable', DetectorTableWorkspace='VirtualInstrumentTable')

# Convert to MDWorkspace
ConvertCWSDExpToMomentum(InputWorkspace='ExpInfoTable', CreateVirtualInstrument=False,
    OutputWorkspace='QSampleMD',
    Directory='')

ConvertCWSDMDtoHKL(InputWorkspace='QSampleMD',
              UBMatrix='0.13329061, 0.07152342, -0.04215966, 0.01084569, -0.1620849, 0.0007607, -0.14018499, -0.07841385, -0.04002737',
              OutputWorkspace='HKLMD')


# Examine
mdws = mtd['QSampleMD']
hklws = mtd['HKLMD']
print('Output QSample and HKL workspaces have %d and %d events.'%(mdws.getNEvents(), hklws.getNEvents()))

BinMD(InputWorkspace='HKLMD', AlignedDim0='H,-0.3,0.3,60', AlignedDim1='K,-0.4,0.5,90', AlignedDim2='L,4,8,10', OutputWorkspace='BinndHKL')
histws = mtd['BinndHKL']
events_array = histws.getNumEventsArray()
print('events[22, 53, 5] = {:.1f}'.format(events_array[22, 53, 5]))
print('events[30, 40, 5] = {:.1f}'.format(events_array[30, 40, 5]))

Output:

Output QSample and HKL workspaces have 1631 and 1631 events.
events[22, 53, 5] = 19.0
events[30, 40, 5] = 38.0

Categories: AlgorithmIndex | Diffraction\ConstantWavelength

Source ¶

C++ header: ConvertCWSDMDtoHKL.h

C++ source: ConvertCWSDMDtoHKL.cpp