3.6

ConvertCWSDMDtoHKL v1

../_images/ConvertCWSDMDtoHKL-v1_dlg.png

ConvertCWSDMDtoHKL dialog.

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.

Description

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

  1. Convert MDEvent’s coordinate system
  2. 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']
print 'Output MDEventWorkspace has %d events.'%(mdws.getNEvents())

hklws = mtd['HKLMD']
print 'H: range from %.5f to %.5f.' % (hklws.getXDimension().getMinimum(), hklws.getXDimension().getMaximum())
print 'K: range from %.5f to %.5f.' % (hklws.getYDimension().getMinimum(), hklws.getYDimension().getMaximum())
print 'L: range from %.5f to %.5f.' % (hklws.getZDimension().getMinimum(), hklws.getZDimension().getMaximum())

Output:

Output MDEventWorkspace has 1631 events.
H: range from -0.24012 to 0.29856.
K: range from -0.41417 to 0.42250.
L: range from 4.83863 to 7.23861.

Categories: Algorithms | Diffraction\ConstantWavelength