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Diffraction Changes¶

Powder Diffraction ¶

Add parameters, LogAllowList and LogBlockList, to AlignAndFocusPowderFromFiles and SNSPowderReduction so users can select which logs are actually needed. The default is to block chopper logs in SNSPowderReduction
Expose the HighBackground option from FitPeaks in PDCalibration
Update HRPD definition to reflect modifications to low-angle bank modules for runs from 01-MAR-23 onwards
Add the ability for CombineDiffCal to have a partial GroupedCalibration workspace. Detectors that do not appear in the GroupedCalibration have calibration constants copied directly from the PixelCalibration workspace without change.
Expose the OffsetData parameter in the Powder Diffraction Reduction GUI
PDCalibration has two new parameters, StartWorkspaceIndex and StopWorkspaceIndex, which limit which spectra are calibrated
PowderReduceP2D has been adapted to work with SNAP measuring data.
AlignAndFocusPowderFromFiles, when it calls LoadDiffCal, it will pass through the TMin parameter. In the case of non-zero TZERO values existing in the calibration constant, the warning message about minimum TOF value shift will now be suppressed.

Fixed bug in absolute unit normalisation in ISIS powder reduction where the vanadium workspace shape was used instead of the sample.
When performing an ISIS powder reduction, errors are raised in absolute normalisation when sample/vanadium shape and material are not provided.
Raise an error in POLARIS (ISIS) powder reduction script if user tries to create a vanadium workspace without correcting for absorption and multiple scattering.
Exposed MSEvents parameter of MayersSampleCorrection to users of ISIS powder reduction scripts (parameter mayers_mult_scat_events in the instrument settings).
Fix type conversion bug producing an error in the cross-correlation functionality of the powder diffraction calibration scripts used in powder diffraction calibration.
Fixed bug in ISIS powder reduction for workspaces being overwritten when focussing using individual batching mode (this affected POLARIS and GEM)
Fixed bug in PDCalibration which was not using the user-input peak windows unless they were pre-sorted, it is no longer necessary to pre-sort peak centers and windows.
Fixed way FitPeaks uses workspace indices in PeakCentersWorkspace and FitPeakWindowWorkspace, to correspond to the same spectrum workspace indices in the input workspace, even when using StartWorkspaceIndex and StopWorkspaceIndex. This fixes the issue with PDCalibration.
Fixed bug in FitPeaks which assumed the zeroeth workspace index defined the largest number of peaks to attempt to fit in all spectra.

Added new SNAPRed menu item for Diffraction interfaces
ISIS Engineering Diffraction UI fitting tab will perform an unweighted average of log values if the proton_charge log doesn’t exist in workspace.

LoadWANDSCD has new keyword argument to apply or not apply goniometer tilts
Update fitting coefficients for BackToBackExponential in SXD parameters xml file.
Add parameter MinIntensOverSigma in SaveReflections to filter peaks to export by Intensity/Sigma
Support saving LeanElasticPeaksWorkspace with GSAS format in SaveReflections (calls SaveHKLCW)
New parameter in SaveIsawUB to rotate the UB by the goniometer matrix.
New algorithm LoadGaussCube to load Gaussian cube files for volumetric data into a 3D MDHistoWorkspace
LoadWANDSCD with grouping option has been sped up
New algorithm FindSXPeaksConvolve to find single-crystal Bragg peaks in instruments with RectangularDetectors (such as SXD).
ISIS single crystal reduction class for SXD now supports defining a file extension when loading data (previously available for WISH class - in both cases the argument to load_run has been renamed to file_ext)
Constant wavelength HFIR DEMAND instrument has been added to DGS Planner

$Instrument view showing the calculated dTOF/TOF resolution for the SNAP instrument (SNS) using the EstimateResolutionDiffraction algorithm.$

Fix bug saving empty peak tables in SaveReflections using SHELX format
Peaks with zero sigma will have Signal/Noise set to zero in FilterPeaks
Now set modUB in IndexPeaks when SaveModulationInfo=True
ISIS single crystal reduction classes now set UB before attempting to transform data to HKL using convert_to_MD method
Fixed bug in ISIS single crystal reduction classes where UB was not set on combined peak table when saving using save_all_peaks method.
Fixed bug in ISIS single crystal reduction classes when defining goniometer angles in process_data method with a sequence (i.e. not using the motor name string)